Initial import of argyll version 1.5.1-8debian/1.5.1-8

1 files changed, 4659 insertions, 0 deletions

diff --git a/scanin/scanrd.c b/scanin/scanrd.c
new file mode 100644
index 0000000..a915e44
--- /dev/null
+++ b/scanin/scanrd.c
@@ -0,0 +1,4659 @@
+
+/*
+ * Raster Color Target Scan Input module
+ * This is the core chart recognition code.
+ * 
+ * Author: Graeme Gill
+ *
+ * Copyright 1995 - 2008 Graeme W. Gill, All right reserved.
+ * This material is licenced under the GNU AFFERO GENERAL PUBLIC LICENSE Version 3 :-
+ * see the License.txt file for licencing details.
+ */
+
+/*
+ * To Do: 
+ *		  Add option to output a raster file made from the .cht and example values.
+ *
+ *        Fix sboxes parameters/digitization to fix "droop" in box areas.
+ *        Scale parameters with image size.
+ *        To handle high res, introduce automatic sub-sampler.
+ *		  Change reference parser to make it more forgiving - use cgats parser ?
+ */
+
+#undef DEBUG
+
+#define VERSION "1.0"
+
+/* Behaviour defines */
+#undef DIAGN				/* Allow diagonal connectivity of groups */
+#define AA_LINES			/* Plot diagnostics using anti-aliased lines */
+
+#define MATCHCC 0.3			/* Match correlation threshold - reject any match under this */
+							/* (Might want to be able to override this in command line) */
+
+#define ALT_ROT_TH 0.7		/* Correlation threshold of alternate rotations to be greater than this */
+
+#define TH (20.0 * 20.0)	/* Initial color change threshhold */
+
+#undef DBG
+#define dbgo stdout
+#define DBG(aaa) fprintf aaa, fflush(dbgo)
+
+#include <stdio.h>
+/* #include <fcntl.h> */		/* In case DOS binary stuff is needed */
+#include <string.h>
+#include <math.h>
+
+#include <stdlib.h>
+#include <sys/stat.h>
+/*  #include <fname.h> */
+
+#include "numlib.h"
+#include "scanrd_.h"
+
+/* ------------------------------------------------- */
+/* Implementations of public functions */
+static void free_scanrd(scanrd *s);
+static int scanrd_reset(scanrd *s);
+static int scanrd_read(scanrd *ps, char *id, double *P, double *mP,
+                       double *sdP, int *cnt);
+static unsigned int scanrd_error(scanrd *s, char **errm);
+
+/* Forward internal function declaration */
+static scanrd_ *new_scanrd(int flags, int verb, double gammav,
+	int (*write_line)(void *ddata, int y, char *src), void *ddata,
+	int w, int h, int d, int td, int p,
+	int (*read_line)(void *fdata, int y, char *dst), void *fdata,
+	char *refname);
+static int read_input(scanrd_ *s);
+static int calc_lines(scanrd_ *s);
+static int show_lines(scanrd_ *s);
+static int calc_perspective(scanrd_ *s);
+static int calc_rotation(scanrd_ *s);
+static int calc_elists(scanrd_ *s, int ref);
+static int write_elists(scanrd_ *s);
+static int read_relists(scanrd_ *s);
+static int do_match(scanrd_ *s);
+static int compute_ptrans(scanrd_ *s);
+static int compute_man_ptrans(scanrd_ *s, double *sfids);
+static int improve_match(scanrd_ *s);
+static int setup_sboxes(scanrd_ *s);
+static int do_value_scan(scanrd_ *s);
+static int compute_xcc(scanrd_ *s);
+//static int restore_best(scanrd_ *s);
+static int show_sbox(scanrd_ *s);
+static int show_groups(scanrd_ *s);
+static int scanrd_write_diag(scanrd_ *s);
+static void toRGB(unsigned char *dst, unsigned char *src, int depth, int bpp);
+static void XYZ2Lab(double *out, double *in);
+static void pval2Lab(double *out, double *in, int depth);
+/* ------------------------------------------------- */
+
+/* Read in a chart, and either create a reference or make values available, */
+/* by using reset() and read() to get values read */
+scanrd *do_scanrd(
+int flags,			/* option flags */
+int verb,			/* verbosity level */
+
+double gammav,		/* Apprimate gamma encoding of image (0.0 = default 2.2) */
+double *sfid,		/* Specified four fiducials x1, y1 .. x4, y4, NULL if auto recognition */
+					/* Typical clockwise from top left */
+
+int w, int h, 		/* Width and Height of input raster in pixels */
+int d, int td, int p,		/* Useful plane depth, Total depth, Bit presision of input pixels */
+int (*read_line)(void *fdata, int y, char *dst),	/* Read RGB line of source file */
+void *fdata,		/* Opaque data for read_line */
+
+char *refname,		/* reference file name */
+
+int (*write_line)(void *ddata, int y, char *src),	/* Write RGB line of diag file */
+void *ddata			/* Opaque data for write_line */
+) {
+	scanrd_ *s;
+
+	/* allocate the basic object */
+	if (verb >= 2)
+		DBG((dbgo,"About to allocate scanrd_ object\n"));
+	if ((s = new_scanrd(flags, verb, gammav, write_line, ddata, w, h, d, td, p, read_line, fdata, refname)) == NULL)
+		return NULL;
+
+	if (s->errv != 0)	/* Some other error from new_scanrd() */
+		return (scanrd *)s;
+
+	if (s->verb >= 2)
+		DBG((dbgo,"About to read input tiff file and discover groups\n"));
+	if (read_input(s))
+		goto sierr;			/* Error */
+
+	if (s->flags & SI_SHOW_GROUPS)
+		if (show_groups(s))
+			goto sierr;		/* Error */
+	
+	if (s->verb >= 2)
+		DBG((dbgo,"About to calculate edge lines\n"));
+	if (calc_lines(s))
+		goto sierr;			/* Error */
+	if (s->verb >= 2)
+		DBG((dbgo,"%d useful edges out of %d\n",s->novlines, s->noslines));
+
+	if (s->flags & SI_PERSPECTIVE) {
+		if (s->verb >= 2)
+			DBG((dbgo,"About to calculate perspective correction\n"));
+		if (calc_perspective(s)) {
+			if (s->flags & SI_SHOW_LINES) {
+				s->flags &= ~SI_SHOW_PERS;	/* Calc perspective failed! */
+				s->flags &= ~SI_SHOW_ROT;	/* Calc rotation not done! */
+				show_lines(s);
+			}
+			goto sierr;			/* Error */
+		}
+	}
+
+	if (s->verb >= 2)
+		DBG((dbgo,"About to calculate rotation\n"));
+	if (calc_rotation(s)) {
+		if (s->flags & SI_SHOW_LINES) {
+			s->flags &= ~SI_SHOW_ROT;	/* Calc rotation failed! */
+			show_lines(s);
+		}
+		goto sierr;			/* Error */
+	}
+
+	if (s->flags & SI_BUILD_REF) { /* If generating a chart reference file */
+		/* Calculate the edge lists and write it to the file */
+		if (s->verb >= 2)
+			DBG((dbgo,"About to build feature information\n"));
+		if (calc_elists(s, 1))		/* reference */
+			goto sierr;		/* Error */
+
+		if (s->verb >= 2)
+			DBG((dbgo,"About to write feature reference information\n"));
+		if (write_elists(s))
+			goto sierr;		/* Error */
+	} else {
+		/* If we are matching to the reference and generating an output data file */
+		int rv;
+
+		/* Calculate the edge lists read for a match */
+		if (s->verb >= 2)
+			DBG((dbgo,"About to calculate feature information\n"));
+		if (calc_elists(s, 0))		/* match */
+			goto sierr;		/* Error */
+
+		if (s->verb >= 2)
+			DBG((dbgo,"About to read reference feature information\n"));
+		if (read_relists(s))
+			goto sierr;		/* Error */
+		if (s->verb >= 2)
+			DBG((dbgo,"Read of chart reference file succeeded\n"));
+
+		if (sfid != NULL) {		/* Manual matching */
+			if (s->verb >= 2)
+				DBG((dbgo,"Using manual matching\n"));
+
+			if (s->havefids == 0) {
+				s->errv = SI_NO_FIDUCIALS_ERR;
+				sprintf(s->errm,"Chart recognition definition file doesn't contain fiducials");
+				goto sierr;		/* Error */
+			}
+			if (compute_man_ptrans(s, sfid))
+				goto sierr;
+
+			/* Do the actual scan given out manual transformation matrix */ 
+			if (s->verb >= 2)
+				DBG((dbgo,"About to setup value scanrdg boxes\n"));
+			if (setup_sboxes(s))	
+				goto sierr;
+			if (s->verb >= 2)
+				DBG((dbgo,"About to read raster values\n"));
+			if (do_value_scan(s))
+				goto sierr;
+
+		} else {				/* Automatic matching */
+
+			/* Attempt to match input file with reference */
+			if (s->verb >= 2)
+				DBG((dbgo,"About to match features\n"));
+			if ((rv = do_match(s)) != 0) {
+				if (rv == 1) {	/* No reasonable rotation found */
+					s->errv = SI_POOR_MATCH;
+					sprintf(s->errm,"Pattern match wasn't good enough");
+				}
+				goto sierr;
+			}
+
+			/* If there is patch matching data and more than one */
+			/* feasible matching rotation, try and discriminate between them. */
+			if (s->xpt && s->norots > 1) {
+				int i, j;
+				int flags = s->flags;
+			
+				s->flags &= ~SI_SHOW_SAMPLED_AREA;	/* Don't show areas for trials */
+
+				/* For each candidate rotation, scan in the pixel values */
+				for (s->crot = 0; s->crot < s->norots; s->crot++) {
+		
+					/* Compute transformation from reference to input file */
+					if (s->verb >= 2)
+						DBG((dbgo,"About to compute match transform for rotation %f deg.\n",
+						          DEG(s->rots[s->crot].irot)));
+					if (compute_ptrans(s))
+						goto sierr;
+			
+					/* Setup the input boxes ready for scanning in the input values */
+					if (s->verb >= 2)
+						DBG((dbgo,"About to setup value scanrdg boxes\n"));
+					if (setup_sboxes(s))	
+						goto sierr;
+			
+					/* Scan in the pixel values */
+					if (s->verb >= 2)
+						DBG((dbgo,"About to read raster values\n"));
+					if (do_value_scan(s))
+						goto sierr;
+		
+					/* Copy to this rotation values so that the best can be restored */
+					if (s->xpt != 0) {			/* Got expected patch values to compare with */
+						if (s->verb >= 2)
+							DBG((dbgo,"About to compute expected value correlation\n"));
+						if (compute_xcc(s))
+							goto sierr;
+					}
+				}
+
+				/* Pick the best from the candidate rotation */
+				if (s->verb >= 2) {
+					DBG((dbgo,"Expected value distance values are:\n"));
+					for (i = 0; i < s->norots; i++) {
+						DBG((dbgo,"%d, rot %f: %f\n", i, DEG(s->rots[i].irot), s->rots[i].xcc));
+					}
+				}
+
+				for (j = 0, i = 1; i < s->norots; i++) {
+					if (s->rots[i].xcc < s->rots[j].xcc)
+						j = i;
+				}
+
+				if (s->verb >= 2)
+					DBG((dbgo,"Chosen rotation %f deg. as best\n",DEG(s->rots[j].irot)));
+	
+				s->crot = j;
+				s->flags = flags;		/* Restore flags */
+			}
+
+			/* Setup transformation to be that for chosen rotation for diagnostics */
+			if (s->verb >= 2)
+				DBG((dbgo,"About to compute final match transform\n"));
+			if (compute_ptrans(s))
+				goto sierr;
+
+			if (s->verb >= 2)
+				DBG((dbgo,"Improve match\n"));
+			if (improve_match(s))
+				goto sierr;
+
+			/* After choosing rotation of improving the fit, rescan the values */
+			if (s->verb >= 2)
+				DBG((dbgo,"About to setup value scanrdg boxes\n"));
+			if (setup_sboxes(s))	
+				goto sierr;
+			if (s->verb >= 2)
+				DBG((dbgo,"About to read raster values\n"));
+			if (do_value_scan(s))
+				goto sierr;
+		}
+
+		if (s->flags & SI_SHOW_SBOX) {
+			show_sbox(s);		/* Draw sample box outlines on diagnostic raster */
+		}
+	}
+	if (s->flags & SI_SHOW_LINES)
+		if(show_lines(s))
+			goto sierr;		/* Error */
+
+sierr:;
+	if (s->verb >= 2)
+		DBG((dbgo,"About to write diag file\n"));
+	if (scanrd_write_diag(s))
+		return (scanrd *)s;	/* Error */
+
+	return (scanrd *)s;
+}
+
+
+/********************************************************************************/
+
+/* Allocate the basic scanrd object */
+/* Return NULL on failure to allocate */
+/* Need to check errv for other problems */
+static scanrd_
+*new_scanrd(
+	int flags,			/* option flags */
+	int verb,			/* verbosity level */
+	double gammav,		/* Approximate gamma encoding of image (0.0 = default 2.2) */
+	int (*write_line)(void *ddata, int y, char *src),	/* Write RGB line of diag file */
+	void *ddata,		/* Opaque data for write_line() */
+	int w, int h, 		/* Width and Height of input raster in pixels */
+	int d, int td, int p,	/* Useful plane Depth, Total depth, Bit presision of input pixels */
+	int (*read_line)(void *fdata, int y, char *dst),	/* Read RGB line of source file */
+	void *fdata,		/* Opaque data for read_line() */
+
+	char *refname		/* reference file name */
+) {
+	scanrd_ *s;
+
+	if ((s = (scanrd_ *)calloc(1, sizeof(scanrd_))) == NULL)
+		return NULL;
+
+	/* Public functions */
+	s->public.reset = scanrd_reset;
+	s->public.read = scanrd_read;
+	s->public.error = scanrd_error;
+	s->public.free = free_scanrd;
+
+	if (flags & (SI_SHOW_ROT | SI_SHOW_PERS | SI_SHOW_IMPL | SI_SHOW_ALL_LINES))
+		flags |= SI_SHOW_LINES;		/* Key all line stuff off SI_SHOW_LINES */
+
+	if (flags & (SI_SHOW_SBOX_OUTLINES | SI_SHOW_SBOX_NAMES | SI_SHOW_SBOX_AREAS))
+		flags |= SI_SHOW_SBOX;;		/* Key all sample box stuff off SI_SHOW_SBOX */
+
+	if (write_line == NULL)
+		flags &= ~SI_SHOW_FLAGS;	/* If no diag file, turn off show flags */
+
+	s->flags = flags;
+	s->verb = verb;
+
+	s->errv = 0;
+	s->errm[0] = '\0';
+
+	if (gammav <= 0.0)
+		gammav = 2.2;			/* default */
+	s->gammav = gammav;
+	s->width = w;
+	s->height = h;
+	s->depth = d;
+	s->tdepth = td;
+	s->bpp = p;
+
+	if (d > MXDE)  {
+		s->errv = SI_PIX_DEPTH_ERR;
+		sprintf(s->errm,"scanrd: Pixel depth is too large");
+		return s;
+	}
+
+	if (p != 8 && p != 16) {
+		s->errv = SI_BIT_DEPTH_ERR;
+		sprintf(s->errm,"scanrd: Pixel bits/pixel is not 8 or 16");
+		return s;
+	}
+	if (p == 8)
+		s->bypp = 1;
+	else
+		s->bypp = 2;
+
+	if (verb >= 2)
+		DBG((dbgo,"Verbosity = %d, flags = 0x%x\n",verb, flags));
+
+	/* RGB Diagnostic output raster array requested */
+	if ((flags & SI_SHOW_FLAGS) && write_line != NULL) {
+		if ((s->out = malloc(3 * w * h)) == NULL) {
+			s->errv = SI_MALLOC_DIAG_RAST;
+			sprintf(s->errm,"scanrd: Diagnostic output raster array malloc failed");
+			return s;
+		}
+	}
+	
+	s->noslines = 0;
+	s->novlines = 0;
+	s->gdone = NULL;
+	s->irot = 0.0;
+	s->norots = 0;
+	
+	s->ppc[0] = 0.0;
+	s->ppc[1] = 0.0;
+	s->ppc[2] = 0.0;
+	s->ppc[3] = 0.0;
+
+	/* Set overall perspective transform to null */
+	s->ptrans[0] = 1.0;
+	s->ptrans[1] = 0.0;
+	s->ptrans[2] = 0.0;
+	s->ptrans[3] = 0.0;
+	s->ptrans[4] = 1.0;
+	s->ptrans[5] = 0.0;
+	s->ptrans[6] = 0.0;
+	s->ptrans[7] = 0.0;
+
+	INIT_ELIST(s->xelist);
+	INIT_ELIST(s->yelist);
+	INIT_ELIST(s->ixelist);
+	INIT_ELIST(s->iyelist);
+	INIT_ELIST(s->rxelist);
+	INIT_ELIST(s->ryelist);
+	s->rbox_shrink = 0.9;
+	s->xpt = 0;
+	
+	s->nsbox = 0;
+	s->sboxes = NULL;
+	s->sbstart = NULL;
+	s->sbend = NULL;
+	s->csi = 0;
+	s->cei = 0;
+	s->alist = NULL;
+	
+	s->next_read = 0;
+
+	s->refname = refname;
+
+	s->inited = 0;
+	s->vrego = s->vregn = NULL;
+	s->no_vo = s->no_vn = 0;
+	s->hrego = s->hregn = NULL;
+	s->no_ho = s->no_hn = 0;
+	s->th = TH;
+	s->divval = 0.25;
+	s->adivval = 0.0;
+	s->divc = 0;
+
+	/* aa line init */
+	s->aa_inited = 0;	/* Let line init do the rest */
+	s->coverage = NULL;
+
+	/* Callbacks */
+	s->read_line = read_line;
+	s->fdata = fdata;
+
+	s->write_line = write_line;
+	s->ddata = ddata;
+
+	return s;
+}
+
+static void free_elist_array(elist *el);
+
+/* Free the object up */
+static void
+free_scanrd(
+scanrd *ps
+) {
+	scanrd_ *s = (scanrd_ *)ps;	/* Cast public to private */
+	points *tp;
+
+	free_elist_array(&s->xelist);
+	free_elist_array(&s->yelist);
+	free_elist_array(&s->ixelist);
+	free_elist_array(&s->iyelist);
+	free_elist_array(&s->rxelist);
+	free_elist_array(&s->ryelist);
+	
+	if (s->sboxes != NULL)
+		free(s->sboxes);
+	if (s->sbstart != NULL)
+		free(s->sbstart);
+	if (s->sbend != NULL)
+		free(s->sbend);
+	s->alist = NULL;
+	
+	/* Free up done line list */
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->r != NULL)
+			free(tp->r);
+		free(tp);
+	END_FOR_ALL_ITEMS(tp);
+	s->gdone = NULL;
+	
+	/* Points were deleted with gdone ??? */
+	if(s->vrego != NULL)
+		free(s->vrego);
+	if(s->vregn)
+		free(s->vregn);
+	if(s->hrego != NULL)
+		free(s->hrego);
+	if(s->hregn != NULL)
+		free(s->hregn);
+	s->inited = 1;
+
+	/* Free up output diag array */
+	if (s->out != NULL)
+		free(s->out);
+	
+	/* Free up aa line array */
+	if (s->coverage != NULL)
+		free(s->coverage);
+	free(s);
+}
+
+
+/* Return the error flag, and set the message pointer */
+static unsigned int
+scanrd_error(scanrd *ps, char **errm) {
+	scanrd_ *s = (scanrd_ *)ps;	/* Cast public to private */
+	*errm = s->errm;
+	return s->errv;
+}
+
+/********************************************************************************/
+static int analize(scanrd_ *s, unsigned char *inp[6], int y);
+
+/* Read in and process the input file */
+/* Return non-zero on error */
+static int
+read_input(scanrd_ *s) {
+	unsigned char *in[6];		/* Pointer to six input buffers */
+	int w = s->width;			/* Raster width */
+	int h = s->height;			/* Raster height */
+	int i, y;
+
+	/* Allocate input line buffers */
+	for (i = 0; i < 6; i++) {
+		if ((in[i] = malloc(s->tdepth * w * s->bypp)) == NULL) {
+			s->errv = SI_MALLOC_INPUT_BUF;
+			sprintf(s->errm,"scanrd: Failed to malloc input line buffers");
+			return 1;
+		}
+	}
+
+	/* Prime the input buffers with 5 lines */
+	for (y = 0; y < 5; y++) {
+		if (s->read_line(s->fdata, y, (char *)in[y])) {
+			s->errv = SI_RAST_READ_ERR;
+			sprintf(s->errm,"scanrd: read_line() returned error");
+			return 1;
+		}
+	}
+	/* Process the tiff file line by line (Assume at least 6 lines in total raster) */
+	for (; y < h; ++y) {
+		unsigned char *tt;
+		if (s->read_line(s->fdata, y, (char *)in[5])) {
+			s->errv = SI_RAST_READ_ERR;
+			sprintf(s->errm,"scanrd: read_line() returned error");
+			return 1;
+		}
+
+		if (analize(s, in, y)) {
+			return 1;
+		}
+
+		tt = in[0];		/* Shuffle buffers about */
+		in[0] = in[1];
+		in[1] = in[2];
+		in[2] = in[3];
+		in[3] = in[4];
+		in[4] = in[5];
+		in[5] = tt;
+
+	}
+	s->adivval /= (double)s->divc;	/* Average divider value, 1.0 = 0 degrees, 0.0 = 45 degrees */
+	if (s->adivval < 0.0)
+		s->adivval = 0.0;
+	else if (s->adivval > 1.0)
+		s->adivval = 1.0;
+
+	if (s->verb >= 2)
+		DBG((dbgo,"adivval = %f\n",s->adivval));
+
+	/* Free the input line buffers */
+	for (i = 0; i < 6; i++)
+		free(in[i]);
+
+	return 0;
+}
+
+/********************************************************************************/
+
+#ifdef NEVER	/* Before 22/5/2004 */
+#define	THRN 1.0			/* Threshold above average ratio - numerator */
+#define	THRD 2.0			/* Threshold above average ratio - denominator */
+
+#define THAWF 1.0 			/* Threshold average adaptation filter weight, fixed value (TH) */
+#define THAWP 4.0 			/* Threshold average adaptation filter weight, previous value */
+#define THAWN 1.0 			/* Threshold average adaptation filter weight, new value */
+
+#else			/* Current values */
+
+#define	THRN 1.0			/* Threshold above average ratio - numerator */
+#define	THRD 1.5			/* Threshold above average ratio - denominator */
+
+#define THAWF 1.0 			/* Threshold average adaptation filter weight, fixed value (TH) */
+#define THAWP 5.0 			/* Threshold average adaptation filter weight, previous value */
+#define THAWN 1.0 			/* Threshold average adaptation filter weight, new value */
+
+#endif
+
+/* ~~~ minimum raster size needs to be specified/checked ~~~~ */
+#define MIN_NO_LINES    16		/* Minimum number of valid fitted lines to estimate rotation */
+
+/* Criteria for accepting lines for angle calculation (valid lines) */
+#define MAX_MWID_TO_LEN    0.1
+#define MIN_POINT_TO_AREA  0.9	/* Minimum point desity over the lines area */
+#define SD_WINDOW          1.5	/* Allow += 1.5 of a standard deviation for robust angle calc. */
+#define ELISTCDIST 800		/* 1/ELISTCDIST = portion of refence edge list legth to coalesce over */
+
+/* Criteria for accepting lines for improring final fit */
+#define IMP_MATCH 0.10			/* Proportion of average tick spacing */
+
+/* The following should be scaled to the resolution of the image ? */
+#define MIN_POINTS 10		/* Minimum points to calculate line */
+#define MIN_LINE_LENGTH    10.0
+#define CUT_CHUNKS 128		/* cut groups along diagonals - must be power of 2 */
+
+static int add_region(scanrd_ *s, region *rego, int no_o, region *regn, int no_n, int y);
+
+/* Process a line of the TIFF file */
+/* return non-zero on error */
+static int
+analize(
+scanrd_ *s,
+unsigned char *inp[6],		/* current and previous 5 lines */
+int y						/* Current line y */
+) {
+	int w = s->width;
+	int stride = s->tdepth * s->width;	/* In pixels */
+	unsigned short *gamma = s->gamma;
+	int x,i;
+	unsigned short *inp2[6];	/* current and previous 5 lines (16bpp) equivalent of inp[] */
+	unsigned char  *in[6];		/* six input lines (8bpp) */
+	unsigned short *in2[6];		/* six input lines (16bpp) */
+	region *tr;
+	double tdh,tdv;				/* Horizontal/virtical detect levels */
+	double tdmag;
+	double atdmag = 0.0;		/* Average magnitude over a line */
+	int atdmagc = 0;			/* Average magnitude over a line count */
+	double linedv = 0.0;		/* Lines average divider value */
+	int linedc = 0;				/* Lines average count */
+	int xo3 = s->tdepth * 3;	/* Xoffset by 3 pixels */
+	int xo2 = s->tdepth * 2;	/* Xoffset by 2 pixels */
+	int xo1 = s->tdepth * 1;	/* Xoffset by 1 pixels */
+
+	for (x = 0; x < 6; x++)		/* Create 16 bpp version of line pointers */
+		inp2[x] = (unsigned short *)inp[x];
+
+	if (s->inited == 0) {
+		/* Init gamma conversion lookup and region tracking. */
+		/* The assumption is that a typical chart has an approx. visually */
+		/* uniform distribution of samples, so that a typically gamma */
+		/* encoded scan image will have an average pixel value of 50%. */
+		/* If a the chart has a different gamma encoding (ie. linear), */
+		/* then we convert it to gamma 2.2 encoded to (hopefuly) enhance */
+		/* the patch contrast. */
+		if (s->bpp == 8)
+		    for (i = 0; i < 256; i++) {
+				int byteb1;
+			
+				byteb1 = (int)(0.5 + 255 * pow( i / 255.0, s->gammav/2.2 ));
+				gamma[i] = byteb1;
+			}
+		else
+		    for (i = 0; i < 65536; i++) {
+				int byteb1;
+			
+				byteb1 = (int)(0.5 + 65535 * pow( i / 65535.0, s->gammav/2.2 ));
+				gamma[i] = byteb1;
+			}
+
+		if ((s->vrego = (region *) malloc(sizeof(region) * (w+1)/2)) == NULL) {
+			s->errv = SI_MALLOC_VREGION;
+			sprintf(s->errm,"vreg malloc failed");
+			return 1;
+		}
+		s->no_vo = 0;
+		if ((s->vregn = (region *) malloc(sizeof(region) * (w+1)/2)) == NULL) {
+			s->errv = SI_MALLOC_VREGION;
+			sprintf(s->errm,"vreg malloc failed");
+			return 1;
+		}
+		s->no_vn = 0;
+		if ((s->hrego = (region *) malloc(sizeof(region) * (w+1)/2)) == NULL) {
+			s->errv = SI_MALLOC_VREGION;
+			sprintf(s->errm,"vreg malloc failed");
+			return 1;
+		}
+		s->no_ho = 0;
+		if ((s->hregn = (region *) malloc(sizeof(region) * (w+1)/2)) == NULL) {
+			s->errv = SI_MALLOC_VREGION;
+			sprintf(s->errm,"vreg malloc failed");
+			return 1;
+		}
+		s->no_hn = 0;
+		INIT_LIST(s->gdone);
+		s->inited = 1;
+	}
+
+	/* Un-gamma correct the latest input line */
+	if (s->bpp == 8)
+		for (x = 0; x < stride; x++)
+			inp[5][x] = (unsigned char)gamma[inp[5][x]];
+	else
+		for (x = 0; x < stride; x++)
+			inp2[5][x] = gamma[inp2[5][x]];
+
+	/* Compute difference output for line y-3 */
+	atdmagc = w - 5;		/* Magnitude count (to compute average) */
+	for (x = 3; x < (w-2); x++) {		/* Allow for -3 to +2 from x */
+		unsigned char *out = s->out;
+		int e;
+		int ss;
+		int idx = ((y-2) * w + x) * 3;		/* Output raster index in bytes */
+
+		if (s->bpp == 8)
+			for (i = 0; i < 6; i++)
+				in[i] = inp[i] + x * s->tdepth;	/* Strength reduce */
+		else
+			for (i = 0; i < 6; i++) {
+				in2[i] = inp2[i] + x * s->tdepth;	/* Strength reduce */
+				in[i] = (unsigned char *)in2[i];	/* track 8bpp pointers */
+			}
+
+		if (s->flags & SI_SHOW_IMAGE) {		/* Create B&W image */
+			toRGB(out + idx, in[2], s->depth, s->bpp);		/* Convert to RGB */
+			out[idx] = out[idx+1] = out[idx+2] = (2 * out[idx] + 7 * out[idx+1] + out[idx+2])/10;
+		}
+
+		ss = 0;		/* Sign of cross components the same vote */
+		tdh = tdv = 0.0;
+		
+		if (s->bpp == 8)
+			for (e = 0; e < s->depth; e++) {
+				int d1,d2;
+				/* Compute Gxp */
+				d1 = -in[0][-xo3+e] + -in[0][-xo2+e] + -in[0][-xo1+e]
+				                              + -in[0][ 0+e] + -in[0][ xo1+e] + -in[0][ xo2+e]
+				   + -in[1][-xo3+e] + -in[1][-xo2+e] + -in[1][-xo1+e]
+				                              + -in[1][ 0+e] + -in[1][ xo1+e] + -in[1][ xo2+e] 
+				   + -in[2][-xo3+e] + -in[2][-xo2+e] + -in[2][-xo1+e]
+				                              + -in[2][ 0+e] + -in[2][ xo1+e] + -in[2][ xo2+e]
+				   +  in[3][-xo3+e] +  in[3][-xo2+e] +  in[3][-xo1+e]
+				                              +  in[3][ 0+e] +  in[3][ xo1+e] +  in[3][ xo2+e]
+				   +  in[4][-xo3+e] +  in[4][-xo2+e] +  in[4][-xo1+e]
+				                              +  in[4][ 0+e] +  in[4][ xo1+e] +  in[4][ xo2+e]
+				   +  in[5][-xo3+e] +  in[5][-xo2+e] +  in[5][-xo1+e]
+				                              +  in[5][ 0+e] +  in[5][ xo1+e] +  in[5][ xo2+e];
+				/* Compute Gyp */
+				d2 = -in[0][-xo3+e] + -in[1][-xo3+e] + -in[2][-xo3+e]
+				                              + -in[3][-xo3+e] + -in[4][-xo3+e] + -in[5][-xo3+e]
+				   + -in[0][-xo2+e] + -in[1][-xo2+e] + -in[2][-xo2+e]
+				                              + -in[3][-xo2+e] + -in[4][-xo2+e] + -in[5][-xo2+e]
+				   + -in[0][-xo1+e] + -in[1][-xo1+e] + -in[2][-xo1+e]
+				                              + -in[3][-xo1+e] + -in[4][-xo1+e] + -in[5][-xo1+e]
+				   +  in[0][   0+e] +  in[1][   0+e] +  in[2][   0+e]
+				                              +  in[3][   0+e] +  in[4][   0+e] +  in[5][   0+e]
+				   +  in[0][+xo1+e] +  in[1][+xo1+e] +  in[2][+xo1+e]
+				                              +  in[3][+xo1+e] +  in[4][+xo1+e] +  in[5][+xo1+e]
+				   +  in[0][+xo2+e] +  in[1][+xo2+e] +  in[2][+xo2+e]
+				                              +  in[3][+xo2+e] +  in[4][+xo2+e] +  in[5][+xo2+e];
+
+				if ((d1 >= 0 && d2 >=0)
+				 || (d1 < 0 && d2 < 0))
+					ss++;				/* Sign was the same */
+				tdh += d1/4.5 * d1/4.5;		/* (4.5 = 6x6/4x2, to scale original tuned values) */
+				tdv += d2/4.5 * d2/4.5;
+			}
+		else
+			for (e = 0; e < s->depth; e++) {
+				int d1,d2;
+				/* Compute Gxp */
+				d1 = -in2[0][-xo3+e] + -in2[0][-xo2+e] + -in2[0][-xo1+e]
+				                              + -in2[0][ 0+e] + -in2[0][ xo1+e] + -in2[0][ xo2+e]
+				   + -in2[1][-xo3+e] + -in2[1][-xo2+e] + -in2[1][-xo1+e]
+				                              + -in2[1][ 0+e] + -in2[1][ xo1+e] + -in2[1][ xo2+e] 
+				   + -in2[2][-xo3+e] + -in2[2][-xo2+e] + -in2[2][-xo1+e]
+				                              + -in2[2][ 0+e] + -in2[2][ xo1+e] + -in2[2][ xo2+e]
+				   +  in2[3][-xo3+e] +  in2[3][-xo2+e] +  in2[3][-xo1+e]
+				                              +  in2[3][ 0+e] +  in2[3][ xo1+e] +  in2[3][ xo2+e]
+				   +  in2[4][-xo3+e] +  in2[4][-xo2+e] +  in2[4][-xo1+e]
+				                              +  in2[4][ 0+e] +  in2[4][ xo1+e] +  in2[4][ xo2+e]
+				   +  in2[5][-xo3+e] +  in2[5][-xo2+e] +  in2[5][-xo1+e]
+				                              +  in2[5][ 0+e] +  in2[5][ xo1+e] +  in2[5][ xo2+e];
+				/* Compute Gyp */
+				d2 = -in2[0][-xo3+e] + -in2[1][-xo3+e] + -in2[2][-xo3+e]
+				                              + -in2[3][-xo3+e] + -in2[4][-xo3+e] + -in2[5][-xo3+e]
+				   + -in2[0][-xo2+e] + -in2[1][-xo2+e] + -in2[2][-xo2+e]
+				                              + -in2[3][-xo2+e] + -in2[4][-xo2+e] + -in2[5][-xo2+e]
+				   + -in2[0][-xo1+e] + -in2[1][-xo1+e] + -in2[2][-xo1+e]
+				                              + -in2[3][-xo1+e] + -in2[4][-xo1+e] + -in2[5][-xo1+e]
+				   +  in2[0][   0+e] +  in2[1][   0+e] +  in2[2][   0+e]
+				                              +  in2[3][   0+e] +  in2[4][   0+e] +  in2[5][   0+e]
+				   +  in2[0][+xo1+e] +  in2[1][+xo1+e] +  in2[2][+xo1+e]
+				                              +  in2[3][+xo1+e] +  in2[4][+xo1+e] +  in2[5][+xo1+e]
+				   +  in2[0][+xo2+e] +  in2[1][+xo2+e] +  in2[2][+xo2+e]
+				                              +  in2[3][+xo2+e] +  in2[4][+xo2+e] +  in2[5][+xo2+e];
+
+				if ((d1 >= 0 && d2 >=0)
+				 || (d1 < 0 && d2 < 0))
+					ss++;				/* Sign was the same */
+				
+				tdh += d1/(4.5 * 257) * d1/(4.5 * 257);		/* Scale to 0..255 range */
+				tdv += d2/(4.5 * 257) * d2/(4.5 * 257);
+			}
+
+		tdmag = tdh + tdv;
+
+		if (tdmag < (32.0 * s->th))
+			atdmag += tdmag;	/* Average magnitude over a line */
+		else
+			atdmag += 32.0 * s->th;
+
+		/* if over threshold */
+		/* (Cut long lines up to prevent long lines being */
+		/* (thrown away due to attached blobs) */
+		if (tdmag >= s->th
+		 && (x & (CUT_CHUNKS-1)) != (y & (CUT_CHUNKS-1))) {
+			double tt;
+			double av;		/* Angle value of current pixel */
+			tt = (tdv - tdh)/(tdh + tdv);	/* Partial angle */
+			linedv += fabs(tt);
+			linedc++;
+
+			if (ss >= (s->depth/2+1))	/* Assume signs are the same if clear majority */
+				av = 3.0 + tt;
+			else
+				av = 1.0 - tt;
+
+			/* Separate the orthogonal elements */
+			if (av  >= s->divval && av < (s->divval + 2.0)) {
+				if (s->flags & SI_SHOW_DIFFSH)
+					out[idx] = (char)255;		/* Red */
+				/* Add point to new region */
+				/* See if we can add to last region */
+				if (s->no_hn > 0 && x == s->hregn[s->no_hn-1].hx)
+					s->hregn[s->no_hn-1].hx++;
+				else {	/* Add another */
+					if (s->no_hn >= (w+1)/2) {
+						s->errv = SI_INTERNAL;
+						sprintf(s->errm,"Internal, no_hn is too large");
+						return 1;
+					}
+					s->hregn[s->no_hn].lx = x;
+					s->hregn[s->no_hn].hx = x+1;
+					s->hregn[s->no_hn].p = NULL;
+					s->no_hn++;
+				}
+			} else {
+				if (s->flags & SI_SHOW_DIFFSV)
+					out[idx+1] = (char)255;		/* Green */
+				/* Add point to new region */
+				/* See if we can add to last region */
+				if (s->no_vn > 0 && x == s->vregn[s->no_vn-1].hx)
+					s->vregn[s->no_vn-1].hx++;
+				else {	/* Add another */
+					if (s->no_vn >= (w+1)/2) {
+						s->errv = SI_INTERNAL;
+						sprintf(s->errm,"Internal, no_vn is too large");
+						return 1;
+					}
+					s->vregn[s->no_vn].lx = x;
+					s->vregn[s->no_vn].hx = x+1;
+					s->vregn[s->no_vn].p = NULL;
+					s->no_vn++;
+				}
+			}
+		}
+	}
+
+	if (linedc != 0) {						/* Adapt divider value to line */
+		linedv /= (double)linedc;			/* Compute average over the line */
+		linedv = (linedv * linedv);			/* Square to even out linedv vs angle */
+		linedv = (1.65 * (linedv - 0.12));	/* Compensate for random offsets */
+		s->adivval += linedv;
+		s->divc++;
+		s->divval = (7.0 * s->divval + linedv)/8.0;		/* Average over 8 lines */
+		if (s->divval < 0.0)
+			s->divval = 0.0;
+		else if (s->divval > 1.0)
+			s->divval = 1.0;
+		if (s->verb >= 5)
+			DBG((dbgo,"linedv = %f, divval = %f\n",linedv,s->divval));
+	}
+
+	/* Adjust the threshold */
+	atdmag /= (double)atdmagc;				/* compute average magnitude over the line */
+	s->th = (s->th * THRD)/(THRN + s->divval);/* Convert threshold to average */
+	s->th = ((THAWF * TH) + (THAWP * s->th) + (THAWN * atdmag))/(THAWF + THAWP + THAWN);
+	s->th = (s->th * (THRN + s->divval))/THRD;	/* Convert average back to threshold */
+
+	/* Add vertical regions */
+	if (add_region(s,s->vrego,s->no_vo,s->vregn,s->no_vn,y-2))
+		return 1;
+
+	/* Add horizontal regions */
+ 	if (add_region(s,s->hrego,s->no_ho,s->hregn,s->no_hn,y-2))
+		return 1;
+
+	/* shuffle them along */
+	tr = s->vrego;
+	s->vrego = s->vregn;	/* move new to old */
+	s->vregn = tr;			/* old to new */
+	s->no_vo = s->no_vn;
+	s->no_vn = 0;
+
+	tr = s->hrego;
+	s->hrego = s->hregn;	/* move new to old */
+	s->hregn = tr;			/* old to new */
+	s->no_ho = s->no_hn;
+	s->no_hn = 0;
+
+	return 0;
+}
+
+/********************************************************************************/
+/* Point list code */
+
+/* allocate a new (empty) points structure */
+/* return NULL on error */
+static points *
+new_points(
+scanrd_ *s
+) {
+	points *ps;
+	static int pn = 0;
+	if ((ps = (points *) malloc(sizeof(points))) == NULL) {
+		s->errv = SI_MALLOC_POINTS;
+		sprintf(s->errm,"new_points: malloc failed");
+		return NULL;
+	}
+	ps->mxno = 0;
+	ps->no = 0;
+	ps->nop = 0;
+	ps->r = NULL;
+	ps->pn = pn;
+	pn++;
+	return ps;
+}
+
+/* destroy a points structure */
+static void
+destroy_points(
+scanrd_ *s,
+points *ps) {
+	if (ps->r != NULL)	/* Free any array pointed to */
+		free(ps->r);
+	free (ps);
+}
+
+/* Add another run to a points object */
+/* return non-zero on error */
+static int
+add_run(
+scanrd_ *s,
+points *ps,
+int lx,
+int hx,
+int y)
+	{
+	if (ps->no == ps->mxno) {	/* Need some more space */
+		ps->mxno = (2 * ps->mxno) + 5;		/* New size */
+		if ((ps->r = (run *) realloc(ps->r, sizeof(run) * ps->mxno)) == NULL) {
+			s->errv = SI_REALLOC_POINTS;
+			sprintf(s->errm,"add_run: realloc failed");
+			return 1;
+		}
+	}
+	ps->r[ps->no].lx = lx;
+	ps->r[ps->no].hx = hx;
+	ps->r[ps->no].y = y;	
+	ps->no++;					/* One more run */
+	ps->nop += hx - lx;			/* Total of pixels */
+	return 0;
+}
+
+/* copy src points to dest */
+/* Return non-zero on error */
+static int
+copy_points(
+scanrd_ *s,
+points *dst,
+points *src
+) {
+	int i;
+	for (i = 0; i < src->no; i++) {
+		if (add_run(s,dst,src->r[i].lx,src->r[i].hx,src->r[i].y))
+			return 1;
+	}
+	return 0;
+}
+
+/********************************************************************************/
+
+/* Add a new region of points to the line points lists */
+/* Note that regions are assumed to be non-overlapping x sorted */
+/* Return non-zero on error */
+static int
+add_region(
+scanrd_ *s,
+region *rego,		/* Old regions */
+int no_o,			/* No of old region */
+region *regn,		/* New regions */
+int no_n,			/* No of new region */
+int y				/* Y value */
+) {
+	int osp,op,np;	/* Old/new pointers */
+
+	osp = 0;
+	for (np = 0; np < no_n; np++) {	/* Process all new runs */
+		/* Advance start pointer until we get to runs that may touch */
+#ifdef DIAGN
+		while (osp < no_o && rego[osp].hx < regn[np].lx)
+#else
+		while (osp < no_o && rego[osp].hx <= regn[np].lx)
+#endif
+			osp++;
+		/* For all old runs that may touch new */
+#ifdef DIAGN
+		for(op = osp; op < no_o && rego[op].lx <= regn[np].hx; op++) {
+#else
+		for(op = osp; op < no_o && rego[op].lx < regn[np].hx; op++) {
+#endif
+
+#ifdef DIAGN
+			if (rego[op].hx >= regn[np].lx  && rego[op].lx <= regn[np].hx) {
+#else
+			if (rego[op].hx > regn[np].lx  && rego[op].lx < regn[np].hx) {
+#endif
+				/* Old region touches new */
+				if (regn[np].p == NULL) {		/* No group for new yet */
+					regn[np].p = rego[op].p;	/* Make part of the same group */
+					if (add_run(s, regn[np].p,regn[np].lx,regn[np].hx,y)) /* add new run to group */
+						return 1;
+				} else if (regn[np].p != rego[op].p) {	/* Touches different group */
+					int j;
+					points *tp = rego[op].p;			/* Old region to be renamed/merged */
+					if (copy_points(s,regn[np].p,tp))	/* Merge old with current new */
+						return 1;	/* Error */
+					DEL_LINK(s->gdone,tp);				/* Don't need other any more */
+					for (j = 0; j < no_o; j++)			/* Fix all references to this group */
+						if (rego[j].p == tp)
+							rego[j].p = regn[np].p;
+					for (j = 0; j < no_n; j++)
+						if (regn[j].p == tp)
+							regn[j].p = regn[np].p;
+					destroy_points(s,tp);
+				}
+			}
+		}
+		/* Finished all relevant old runs */
+		if (regn[np].p == NULL) {	/* No old touched, so start new group */
+			if ((regn[np].p = new_points(s)) == NULL)
+				return 1;		/* Error */
+			ADD_ITEM_TO_TOP(s->gdone,regn[np].p);	/* Stash it in points list */
+			if (add_run(s, regn[np].p,regn[np].lx,regn[np].hx,y))	/* add new run to group */
+				return 1;		/* Error */
+		}
+	}
+	return 0;
+}
+
+/********************************************************************************/
+
+/* Apply partial perspective to an xy point */
+/* (We omit the two offset parameters, since we don't need them) */
+void ppersp(scanrd_ *s, double *xx, double *yy, double x, double y, double *ppc) {
+	double den;
+
+	/* Offset the partial perspective transform */
+	x -= ppc[2];
+	y -= ppc[3];
+
+	den = ppc[0] * x + ppc[1] * y + 1.0;
+
+	if (fabs(den) < 1e-6) {
+		if (den < 0.0)
+			den = -1e-6;
+		else
+			den = 1e-6;
+	}
+	*xx = x/den + ppc[2];
+	*yy = y/den + ppc[3];
+}
+
+
+/* Apply inverse partial perspective to an xy point */
+void invppersp(scanrd_ *s, double *x, double *y, double xx, double yy, double *ppc) {
+	double den;
+
+	/* Offset the partial perspective transform */
+	xx -= ppc[2];
+	yy -= ppc[3];
+
+	den = - ppc[0] * xx - ppc[1] * yy + 1.0;
+
+	if (fabs(den) < 1e-6) {
+		if (den < 0.0)
+			den = -1e-6;
+		else
+			den = 1e-6;
+	}
+	*x = xx/den + ppc[2];
+	*y = yy/den + ppc[3];
+}
+
+/********************************************************************************/
+
+/* Compute the least squares best line fit for a group */
+/* Return non-zero if failed */
+static int
+points_to_line(
+scanrd_ *s,
+points *ps) {
+	int i,j;
+	point *vv;			/* Point vectors */
+	int nop = ps->nop;	/* Number of points */
+	double sx,sy;		/* Sum */
+	double mx,my;		/* Mean */
+	double a;			/* Angle, Clockwise from 12o'clock */
+	double mw,len;		/* mean width, length */
+	double x1,y1,x2,y2;	/* Start/end point of fitted line */
+
+	ps->flag = 0;
+
+	if (nop < MIN_POINTS)			/* Don't bother if too few pixels */
+		return 0;
+
+	/* Convert runs to individual points, and compute mean */
+	if ((vv = (point *) malloc(sizeof(point) * nop)) == NULL) {
+		s->errv = SI_MALLOC_POINT2LINE;
+		sprintf(s->errm,"scanrd: points_to_line: malloc failed");
+		return 1;
+	}
+
+	sx = sy = 0.0;
+	for (j = i = 0; i < ps->no; i++) {	/* For all runs */
+		int x,y;
+		int hx = ps->r[i].hx, lx = ps->r[i].lx;
+
+		y = ps->r[i].y;
+		sy += (hx - lx) * y;
+		for (x = lx; x < hx; x++, j++) {	/* Convert to points */
+			sx += x;
+			vv[j].x = x;
+			vv[j].y = y;
+		}
+	}
+	mx = sx/(double)nop;	/* Centroid (mean) of points */
+	my = sy/(double)nop;
+
+	/* Offset points to centroid */
+	for (i=0; i < nop; i++) {
+		vv[i].x -= mx;
+		vv[i].y -= my;
+	}
+	
+	/* Compute ad and bd, then A, B, C */
+	/* From Graphics Gems V, pp 91-97, */
+	/* "The Best Least-Squares Line Fit" */
+	/* by David Alciatore and Rick Miranda. */
+	{
+		double ad, bd;		/* a' and b' values */
+		double xd, yd;		/* temp x' and y' */
+		double A, B;		/* line equation */
+		double abn;			/* A & B normalizer */
+
+		xd = yd = bd = 0.0;
+		for (i = 0; i < nop; i++) {
+			double x, y;
+
+			x = vv[i].x;
+			y = vv[i].y;
+			xd += x * x;
+			yd += y * y;
+			bd += x * y;
+		}
+		ad = xd - yd;
+
+		/* Equation of best fit line is Ax + By = C */
+		A = 2 * bd;
+		B = -(ad + sqrt(ad * ad + 4.0 * bd * bd));
+		/* C = A * mx + B * my; */
+
+		/* Compute angle */
+		/* A = abn * cos(a), B = -abn * sin(a) */
+
+		abn = sqrt(A * A + B * B);	/* Normalize A & B */
+		if (fabs(abn) < 1e-6) {		/* No dominant direction */
+			a = 0.0;
+		} else {
+			a = acos(A/abn);
+		}
+		/* Make angle +ve */
+		while (a < 0.0) a += M_PI;
+	}
+
+	/* Now figure out the bounding box for the line + other stats */
+	{
+		double s,c;
+		double pl,nl;		/* Positive length, negative length */
+		s = sin(a);
+		c = cos(a);
+		for (mw = 0.0, pl = 0.0, nl = 0.0, i = 0; i < nop; i++)
+			{
+			double npj;		/* Projection onto normal */
+			double lpj;		/* Projection onto line */
+			npj = -c * vv[i].x + s * vv[i].y;
+			if (npj < 0)
+				mw -= npj;
+			else
+				mw += npj;
+			lpj = s * vv[i].x + c * vv[i].y;
+			if (lpj > pl)
+				pl = lpj;
+			if (lpj < nl)
+				nl = lpj;
+			}
+		mw = 2.0 * mw/(double)nop;		/* Mean width */
+	
+		x1 = mx + s * nl;
+		y1 = my + c * nl;
+		x2 = mx + s * pl;
+		y2 = my + c * pl;
+		len = pl - nl;
+	}
+
+	ps->mx = mx;		/* Mean point */
+	ps->my = my;
+	ps->a = a;			/* Angle */
+	ps->mw = mw;		/* Mean width */
+	ps->len = len;		/* Mean length */
+	ps->x1 = x1;		/* Start/end point of fitted line */
+	ps->y1 = y1;
+	ps->x2 = x2;
+	ps->y2 = y2;
+	ps->flag = F_LINESTATS;	/* Line stats valid */
+
+	/* Compute the Constrained to 90 degrees angle */
+	/* We use the adivval to figure out where to split angles */
+	/* Split at 0 if adivval == 0.0, split at 45 if adivval == 1.0 */
+	if (a >= (M_PI * (1.0 - s->adivval/4.0)))
+		ps->ca = a - M_PI;
+	else if (a >= (M_PI * (0.5 - s->adivval/4.0)))
+		ps->ca = a - M_PI_2;
+	else
+		ps->ca = a;
+
+	if (s->verb >= 5)
+	 	DBG((dbgo,"Angle %f, CA = %f, length = %f, mean width  = %f, Line %f,%f to %f,%f\n",
+			DEG(a),DEG(ps->ca),len,mw,x1,y1,x2,y2));
+	free(vv);
+
+/* printf("~~stats: mw = %f, len = %f, mw/len = %f, area = %f\n",
+	mw, len, mw/len, ((double)nop/(len * (mw + 0.01)))); */
+	/* Look at stats to see what lines are acceptable for further processing */
+	if ( len >= MIN_LINE_LENGTH
+	  && mw/len <= MAX_MWID_TO_LEN
+	  && ((double)nop/(len * (mw + 0.01))) >= MIN_POINT_TO_AREA) {
+		ps->flag |= F_VALID;	/* Line stats valid to use */
+/* printf("~~set valid\n"); */
+	}
+	return 0;
+}
+
+static int
+calc_lines(
+scanrd_ *s
+) {
+	points *tp;
+	s->noslines = 0;
+	s->novlines = 0;
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		if (points_to_line(s,tp))
+			return 1;				/* Error */
+		if (tp->flag & F_LINESTATS)	/* Line stats valid */
+			s->noslines++;
+		if (tp->flag & F_VALID)		/* Valid for angle calcs */
+			s->novlines++;
+
+		/* Save orininal raster (non partial perspective corrected) values */
+		if (tp->flag & F_VALID) {
+			tp->pmx = tp->mx;
+			tp->pmy = tp->my;
+			tp->px1 = tp->x1;
+			tp->py1 = tp->y1;
+			tp->px2 = tp->x2;
+			tp->py2 = tp->y2;
+		}
+	END_FOR_ALL_ITEMS(tp);
+	return 0;
+}
+
+static int show_line(scanrd_ *s, int x1, int y1, int x2, int y2, unsigned long c);
+
+/* Show the edge detected lines */
+static int
+show_lines(
+scanrd_ *s
+) {
+	points *tp;
+	int outw = s->width;
+	int outh = s->height;
+	/* For SI_SHOW_ROT */
+	double cirot,sirot;		/* cos and sin of -irot */
+	cirot = cos(-s->irot);
+	sirot = sin(-s->irot);
+
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		if ((s->flags & SI_SHOW_ALL_LINES) || (tp->flag & F_VALID))
+			{
+			unsigned long col = 0xffffff;		/* default color is white */
+			double x1 = tp->px1, y1 = tp->py1, x2 = tp->px2, y2 = tp->py2;
+			/* For SI_SHOW_ROT */
+
+			/* Show partial perspective corrected lines */
+			if (s->flags & (SI_SHOW_ROT | SI_SHOW_PERS)) {
+				invppersp(s, &x1, &y1, x1, y1, s->ppc);
+				invppersp(s, &x2, &y2, x2, y2, s->ppc);
+				col = 0xffff00;	/* cyan */
+			}
+
+			/* Show rotation correction of lines + color coding yellow and red */
+			if (s->flags & SI_SHOW_ROT) {
+				double tx1, ty1, tx2, ty2;
+				double a = tp->a - s->irot;
+
+				tx1 = x1;
+				ty1 = y1;
+				tx2 = x2;
+				ty2 = y2;
+
+				/* Rotate about center of raster */
+				x1 = (tx1-outw/2.0) * cirot + (ty1-outh/2.0) * sirot;
+				y1 = -(tx1-outw/2.0) * sirot + (ty1-outh/2.0) * cirot;
+				x2 = (tx2-outw/2.0) * cirot + (ty2-outh/2.0) * sirot;
+				y2 = -(tx2-outw/2.0) * sirot + (ty2-outh/2.0) * cirot;
+
+				x1 += outw/2.0;		/* Rotate about center of raster */
+				y1 += outh/2.0;
+				x2 += outw/2.0;
+				y2 += outh/2.0;
+				if ((a >= -0.08 && a <= 0.08) || (a >= (M_PI-0.08) && a <= (M_PI+0.08))
+				 || (a >= (M_PI_2-0.08) && a <= (M_PI_2+0.08)))
+					col = 0x00ffff;	/* yellow */
+				else
+					col = 0x0000ff;	/* Red */
+			}
+			/* Show just lines used for fit improvement in blue */
+			if (s->flags & SI_SHOW_IMPL) {
+				if (tp->flag & F_IMPROVE)
+					col = 0xff4040;	/* blue */
+			}
+			show_line(s,(int)(x1+0.5),(int)(y1+0.5),(int)(x2+0.5),(int)(y2+0.5),col);
+		}
+	END_FOR_ALL_ITEMS(tp);
+	return 0;
+}
+
+
+/********************************************************************************/
+
+/* Definition of the optimization function handed to powell() */
+static double
+pfunc(void *ss, double p[]) {
+	scanrd_ *s = (scanrd_ *)ss;
+	points *tp;
+	double aa;		/* Average angle */
+	double va, rva;	/* Variance */
+	double wt;		/* Total weighting = sum of line lengths */
+	double pw;
+	double dw;		/* Discrimination width */
+	
+//printf("~1 %f %f %f %f %f %f\n", p[0],p[1],p[2],p[3],p[4],p[5]);
+
+	/* Correct the perspective of all the edge lines using the parameters */
+	/* and compute the mean angle */
+	aa = 0.0;		/* Average constrained angle */
+	wt = 0.0;		/* Total weighting = sum of line lengths */
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->flag & F_LONGENOUGH) {
+			double a, ca;
+			invppersp(s, &tp->x1, &tp->y1, tp->px1, tp->py1, p);
+			invppersp(s, &tp->x2, &tp->y2, tp->px2, tp->py2, p);
+
+			/* Compute the angle */
+			a = atan2(tp->x2 - tp->x1,tp->y2 - tp->y1);
+
+			/* Make angle +ve */
+			while (a < 0.0)
+				a += M_PI;
+
+			/* Compute the Constrained to 90 degrees angle */
+			/* We use the adivval to figure out where to split angles */
+			/* Split at 0 if adivval == 0.0, split at 45 if adivval == 1.0 */
+			if (a >= (M_PI * (1.0 - s->adivval/4.0)))
+				ca = a - M_PI;
+			else if (a >= (M_PI * (0.5 - s->adivval/4.0)))
+				ca = a - M_PI_2;
+			else
+				ca = a;
+
+			tp->a = a;
+			tp->ca = ca;
+
+			aa += tp->len * ca;
+			wt += tp->len;
+		}
+	END_FOR_ALL_ITEMS(tp);
+	aa /= wt;
+
+	/* Calculate the angle variance */
+	va = 0.0;
+	tp = s->gdone;
+	wt = 0.0;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->flag & F_LONGENOUGH) {
+			double tt;
+			tt = tp->ca - aa;
+			va += tp->len * tt * tt;
+			wt += tp->len;
+		}
+	END_FOR_ALL_ITEMS(tp);
+	va = va/wt;
+
+	/* Calculate the a robust angle variance */
+	rva = 0.0;
+	wt = 0.0;
+	dw = sqrt(va) * 3.1;		/* Allow += 0.5 of a standard deviation */
+	if (dw < 0.0001)			/* A perfect chart may have dw of zero */
+		dw = 0.0001;
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->flag & F_LONGENOUGH && fabs(tp->ca - aa) <= dw) {
+			double tt;
+			tt = tp->ca - aa;
+			rva += tp->len * tt * tt;
+			wt += tp->len;
+		}
+	END_FOR_ALL_ITEMS(tp);
+	if (wt > 0.0) {
+		rva = rva/wt;
+		va = rva;
+	}
+
+	/* Add some regularization to stop it going crazy */
+	pw = 0.0;
+	pw += 0.01 * (fabs(p[0]) + fabs(p[1]));
+	pw += 0.0001 * (fabs(p[2]/s->width - 0.5) + fabs(p[3]/s->height - 0.5));
+	va += pw;
+
+	return va;
+}
+
+/* Calculate the partial perspective correction factors */
+/* Return non-zero if failed */
+static int
+calc_perspective(
+scanrd_ *s
+) {
+	points *tp;
+	int nl;			/* Number of lines used */
+	double ml;		/* Minimum length */
+	double pc[4];	/* Perspective factors */
+	double ss[4];	/* Initial search distance */
+	double rv;		/* Return value */
+	int rc = 0;		/* Return code */
+
+	if (s->novlines < MIN_NO_LINES) {
+		s->errv = SI_FIND_PERSPECTIVE_FAILED;
+		sprintf(s->errm,"Not enough valid lines to compute perspective");
+		return 1;
+	}
+
+	/* Find the longest line */
+	ml = 0.0;
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->flag & F_VALID) {
+			if (tp->len > ml)
+				ml = tp->len;
+		}
+	END_FOR_ALL_ITEMS(tp);
+	
+	/* Make minimum line length to be included in angle */
+	/* calculation 1% of longest line */
+	ml *= 0.01;
+
+	/* Mark lines long enough to participate in angle calculation */
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->flag & F_VALID && tp->len >= ml)
+			tp->flag |= F_LONGENOUGH;
+	END_FOR_ALL_ITEMS(tp);
+
+	/* Locate the perspective correction factors that minimze the */
+	/* variance of the mean angle. */
+
+	pc[0] = 0.0;
+	pc[1] = 0.0;
+	pc[2] = 0.5 * s->width;
+	pc[3] = 0.5 * s->height;
+
+	ss[0] = 0.0001;
+	ss[1] = 0.0001;
+	ss[2] = 1.0001;
+	ss[3] = 1.0001;
+	rc = powell(&rv, 4, pc,ss,1e-8,2000,pfunc,s, NULL, NULL);
+
+	if (rc == 0) {
+		points *tp;
+	
+		DBG((dbgo,"Perspective correction factors = %f %f %f %f\n",
+		       pc[0],pc[1],pc[2],pc[3]));
+		
+		s->ppc[0] = pc[0];
+		s->ppc[1] = pc[1];
+		s->ppc[2] = pc[2];
+		s->ppc[3] = pc[3];
+
+		/* Implement the perspective correction */
+		tp = s->gdone;
+		FOR_ALL_ITEMS(points, tp)
+			if (tp->flag & F_LONGENOUGH) {
+				double a, ca;
+				invppersp(s, &tp->x1, &tp->y1, tp->px1, tp->py1, s->ppc);
+				invppersp(s, &tp->x2, &tp->y2, tp->px2, tp->py2, s->ppc);
+				tp->mx = 0.5 * (tp->x2 + tp->x1);
+				tp->my = 0.5 * (tp->y2 + tp->y1);
+				tp->len = sqrt((tp->x2 - tp->x1) * (tp->x2 - tp->x1)
+				             + (tp->y2 - tp->y1) * (tp->y2 - tp->y1));
+	
+				/* Compute the angle */
+				a = atan2(tp->x2 - tp->x1,tp->y2 - tp->y1);
+	
+				/* Make angle +ve */
+				while (a < 0.0)
+					a += M_PI;
+	
+				/* Compute the Constrained to 90 degrees angle */
+				/* We use the adivval to figure out where to split angles */
+				/* Split at 0 if adivval == 0.0, split at 45 if adivval == 1.0 */
+				if (a >= (M_PI * (1.0 - s->adivval/4.0)))
+					ca = a - M_PI;
+				else if (a >= (M_PI * (0.5 - s->adivval/4.0)))
+					ca = a - M_PI_2;
+				else
+					ca = a;
+	
+				tp->a = a;
+				tp->ca = ca;
+			}
+		END_FOR_ALL_ITEMS(tp);
+	}
+
+	return 0;
+}
+
+/********************************************************************************/
+/* Calculate the image rotation */
+/* Return non-zero if failed */
+static int
+calc_rotation(
+scanrd_ *s
+) {
+	points *tp;
+	int nl;			/* Number of lines used */
+	double ml;		/* Minimum length */
+	double aa;		/* Average angle */
+	double sd,dw;	/* Standard deviation, deviation window */
+	double wt;		/* Total weighting = sum of line lengths */
+
+	if (s->novlines < MIN_NO_LINES) {
+		s->errv = SI_FIND_ROTATION_FAILED;
+		sprintf(s->errm,"Not enough valid lines to compute rotation angle");
+		return 1;
+	}
+
+	/* Find the longest line */
+	tp = s->gdone;
+	ml = 0.0;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->flag & F_VALID) {
+			if (tp->len > ml)
+				ml = tp->len;
+		}
+	END_FOR_ALL_ITEMS(tp);
+	
+	/* Make minimum line length to be included in angle */
+	/* calculation 1% of longest line */
+	ml *= 0.01;
+
+	/* Calculate the mean angle */
+	aa = 0.0;
+	wt = 0.0;		/* Total weighting = sum of line lengths */
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->flag & F_VALID && tp->len >= ml) {
+			aa += tp->len * tp->ca;
+			wt += tp->len;
+		}
+	END_FOR_ALL_ITEMS(tp);
+	aa /= wt;
+
+	if (s->verb >= 2)
+		DBG((dbgo,"Mean angle = %f\n",DEG(aa)));
+
+	/* Calculate the angle standard deviation */
+	tp = s->gdone;
+	sd = 0.0;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->flag & F_VALID && tp->len >= ml) {
+			double tt;
+			tt = tp->ca - aa;
+			sd += tp->len * tt * tt;
+		}
+	END_FOR_ALL_ITEMS(tp);
+
+	sd = sqrt(sd/wt);
+
+	if (s->verb >= 2)
+		DBG((dbgo,"Standard deviation = %f\n",DEG(sd)));
+
+	/* Now re-compute the angle while rejecting any that fall outside one standard deviation */
+	s->irot = 0.0;
+	wt = 0.0;					/* Total weighting = sum of line lengths */
+	nl = 0;
+	dw = sd * SD_WINDOW;		/* Allow += 0.5 of a standard deviation */
+	if (dw < 0.01)				/* A perfect chart may have dw of zero */
+		dw = 0.01;
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->flag & F_VALID && tp->len >= ml && fabs(tp->ca - aa) <= dw) {
+			s->irot += tp->len * tp->ca;
+			wt += tp->len;
+			nl++;
+		}
+	END_FOR_ALL_ITEMS(tp);
+	if (nl < (MIN_NO_LINES/2)) {
+		s->errv = SI_FIND_ROTATION_FAILED;
+		sprintf(s->errm,"%d consistent lines is not enough to compute rotation angle",nl);
+		return 1;
+	}
+	s->irot /= wt;
+
+	if (s->verb >= 2)
+		DBG((dbgo,"Robust mean angle = %f from %d lines\n",DEG(s->irot),nl));
+
+	return 0;
+}
+
+/********************************************************************************/
+/* Coalesce close entries of an edge list */
+/* return non-zero on error */
+static int
+coalesce_elist(
+scanrd_ *s,
+elist *el,
+int close			/* Closeness factor, smaller = coarser */
+) {
+	double r;		/* Margin for coalescence */
+	int i,k;
+
+	if (el->c < 2)		/* Need at least 2 entries */
+		return 0;
+
+	r = (el->a[el->c-1].pos - el->a[0].pos)/(double)close;
+	for (k = 0, i = 1; i < el->c; i++) {
+		if ((el->a[i].pos - el->a[k].pos) <= r) {
+			/* Merge the two */
+			double lk = el->a[k].len;
+			double li = el->a[i].len;
+			el->a[k].pos = (el->a[k].pos * lk + el->a[i].pos * li)/(lk + li);
+			el->a[k].len = lk + li;
+			if (el->a[k].p1 > el->a[i].p1)		/* Track overall start/end points */
+				el->a[k].p1 = el->a[i].p1;
+			if (el->a[k].p2 < el->a[i].p2)
+				el->a[k].p2 = el->a[i].p2;
+			continue;
+		}
+		k++;		/* Inc destination pointer */
+		if (k != i)
+			el->a[k] = el->a[i];	/* shuffle data down */
+	}
+	k++;		/* one past last out entry */
+	el->c = k;
+	return 0;
+}
+
+static int invert_elist(scanrd_ *s, elist *dl, elist *sl);
+static void debug_elist(scanrd_ *s, elist *el);
+
+/* Make up the x and y edge lists */
+/* Return non-zero if failed */
+static int
+calc_elists(
+scanrd_ *s,
+int ref			/* 1 if generating reference lists */
+) {
+	int outw = s->width;
+	int outh = s->height;
+	points *tp;
+	int i,j;
+	double cirot,sirot;		/* cos and sin of -irot */
+	elist xl, yl;	/* Temporary X and Y edge lists array */
+	elist tl;		/* temporary crossing list */
+
+	/* Allocate structures for edge lists */
+	if ((xl.a = (epoint *) malloc(sizeof(epoint) * s->novlines)) == NULL) {
+		s->errv = SI_MALLOC_ELIST;
+		sprintf(s->errm,"scanrd: calc_elist: malloc failed - novlines = %d",s->novlines);
+		return 1;
+	}
+	xl.c = 0;
+	if ((yl.a = (epoint *) malloc(sizeof(epoint) * s->novlines)) == NULL) {
+		s->errv = SI_MALLOC_ELIST;
+		sprintf(s->errm,"scanrd: calc_elist: malloc failed - novlines = %d",s->novlines);
+		return 1;
+	}
+	yl.c = 0;
+
+	/* Put valid lines into one of the two edge list arrays */
+	cirot = cos(-s->irot);
+	sirot = sin(-s->irot);
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->flag & F_VALID) {
+			/* Rotate the point about 0,0 by angle -irot */
+			double x,y,a;
+			double mx = tp->mx, my = tp->my;
+			
+			if (ref) {	/* Rotate about center of raster for reference generation */
+				mx -= outw/2.0;		/* Rotate about center of raster */
+				my -= outh/2.0;
+				x = mx * cirot + my * sirot + outw/2.0;
+				y = -mx * sirot + my * cirot + outh/2.0;
+			} else {	/* Rotate about 0,0 for matching */
+				x = mx * cirot + my * sirot;
+				y = -mx * sirot + my * cirot;
+			}
+			a = tp->a - s->irot;
+			if ((a >= -0.08 && a <= 0.08) || (a >= (M_PI-0.08) && a <= (M_PI+0.08))) {
+				xl.a[xl.c].pos = x;
+				xl.a[xl.c].len = tp->len;
+				xl.a[xl.c].p1 = y - tp->len/2.0;
+				xl.a[xl.c].p2 = y + tp->len/2.0;
+				xl.c++;
+			} else if (a >= (M_PI_2-0.08) && a <= (M_PI_2+0.08)) {
+				yl.a[yl.c].pos = y;
+				yl.a[yl.c].len = tp->len;
+				yl.a[yl.c].p1 = x - tp->len/2.0;
+				yl.a[yl.c].p2 = x + tp->len/2.0;
+				yl.c++;
+			}
+		}
+	END_FOR_ALL_ITEMS(tp);
+
+	/* ~~~~ need to check that lists have a reasonable number of entries ~~~~~ */
+
+	/* now sort the lists */
+#define HEAP_COMPARE(A,B)  (A.pos < B.pos)
+	HEAPSORT(epoint,xl.a,xl.c);
+	HEAPSORT(epoint,yl.a,yl.c);
+#undef HEAP_COMPARE
+	
+	/* Copy the temporary lists to the real lists */
+	if ((s->xelist.a = (epoint *) malloc(sizeof(epoint) * xl.c)) == NULL) {
+		s->errv = SI_MALLOC_ELIST;
+		sprintf(s->errm,"scanrd: calc_elist: malloc failed, xl.c = %d",xl.c);
+		return 1;
+	}
+	s->xelist.c = xl.c;
+	for (i=0; i < xl.c; i++)
+		s->xelist.a[i] = xl.a[i];
+	if ((s->yelist.a = (epoint *) malloc(sizeof(epoint) * yl.c)) == NULL) {
+		s->errv = SI_MALLOC_ELIST;
+		sprintf(s->errm,"scanrd: calc_elist: malloc failed, yl.c = %d",yl.c);
+		return 1;
+	}
+	s->yelist.c = yl.c;
+	for (i=0; i < yl.c; i++)
+		s->yelist.a[i] = yl.a[i];
+
+	/* Coalese close entries of the final lists */
+	if (coalesce_elist(s, &s->xelist,ELISTCDIST))
+		return 1;
+	if (coalesce_elist(s, &s->yelist,ELISTCDIST))
+		return 1;
+
+	/* Calculate crossing count for lines in the X and y lists */
+	if ((tl.a = (epoint *) malloc(sizeof(epoint) * (xl.c > yl.c ? xl.c : yl.c))) == NULL) {
+		s->errv = SI_MALLOC_ELIST;
+		sprintf(s->errm,"scanrd: calc_elist: malloc failed, xl.c = %d, yl.c = %d",xl.c,yl.c);
+		return 1;
+	}
+	/* X list */
+	for (i = 0; i < s->xelist.c; i++) {
+		double ppos = s->xelist.a[i].pos;
+		double pp,np;		/* Previous and next pos */
+		if ((i-1) >= 0)
+			pp = (ppos + s->xelist.a[i-1].pos)/2.0;	/* Half distance to next line */
+		else
+			pp = -1e6;
+		if ((i+1) < s->xelist.c)
+			np = (ppos + s->xelist.a[i+1].pos)/2.0;	/* Half distance to next line */
+		else
+			np = 1e6;
+
+		/* For all the lines in the Y list */
+		for (tl.c = j = 0; j < yl.c; j++) {
+			double pos = yl.a[j].pos;
+			double p1 = yl.a[j].p1;
+			double p2 = yl.a[j].p2;
+			if (p1 <= pp)
+				p1 = pp;
+			if (p2 >= np)
+				p2 = np;
+			/* If crosses on this lines X within +-0.5 of line each side */
+			if (p1 <= np && p2 >= pp) {
+				tl.a[tl.c].pos = pos;
+				tl.a[tl.c].len = p2 - p1;
+				tl.a[tl.c].p1 = p1;
+				tl.a[tl.c].p2 = p2;
+				tl.c++;
+			}
+		}
+		/* now coalesce the crossings */
+		if (coalesce_elist(s,&tl,200))
+			return 1;
+		/* Put count in line we're working on */
+		s->xelist.a[i].ccount = (double)tl.c;
+		pp = ppos;
+	}
+
+	/* Y list */
+	for (i = 0; i < s->yelist.c; i++) {
+		double ppos = s->yelist.a[i].pos;
+		double pp,np;		/* Previous and next pos */
+		if ((i-1) >= 0)
+			pp = (ppos + s->yelist.a[i-1].pos)/2.0;	/* Half distance to next line */
+		else
+			pp = -1e6;
+		if ((i+1) < s->xelist.c)
+			np = (ppos + s->yelist.a[i+1].pos)/2.0;	/* Half distance to next line */
+		else
+			np = 1e6;
+
+		for (tl.c = j = 0; j < xl.c; j++) {
+			double pos = xl.a[j].pos;
+			double p1 = xl.a[j].p1;
+			double p2 = xl.a[j].p2;
+			if (p1 <= pp)
+				p1 = pp;
+			if (p2 >= np)
+				p2 = np;
+			/* If crosses on this lines Y within +-0.5 of line each side */
+			if (p1 <= np && p2 >= pp) {
+				tl.a[tl.c].pos = pos;
+				tl.a[tl.c].len = p2 - p1;
+				tl.a[tl.c].p1 = p1;
+				tl.a[tl.c].p2 = p2;
+				tl.c++;
+			}
+		}
+		/* now coalesce the crossings */
+		if (coalesce_elist(s,&tl,200))
+			return 1;
+		/* Put count in line we're working on */
+		s->yelist.a[i].ccount = (double)tl.c;
+		pp = ppos;
+	}
+
+	/* Normalize the length and ccount */
+		{
+		double tlen;	/* Total length maximum */
+		double tcmax;	/* Total count maximum */
+		for (tlen = tcmax = 0.0, i=0; i < s->xelist.c; i++) {
+			if (tlen < s->xelist.a[i].len)
+				tlen = s->xelist.a[i].len;
+			if (tcmax < s->xelist.a[i].ccount)
+				tcmax = s->xelist.a[i].ccount;
+		}
+		for (i=0; i < s->xelist.c; i++) {
+			s->xelist.a[i].len /= tlen;
+			s->xelist.a[i].ccount /= tcmax;
+		}
+		for (tlen = tcmax = 0.0, i=0; i < s->yelist.c; i++) {
+			if (tlen < s->yelist.a[i].len)
+				tlen = s->yelist.a[i].len;
+			if (tcmax < s->yelist.a[i].ccount)
+				tcmax = s->yelist.a[i].ccount;
+		}
+		for (i=0; i < s->yelist.c; i++) {
+			s->yelist.a[i].len /= tlen;
+			s->yelist.a[i].ccount /= tcmax;
+		}
+	}
+
+	/* Create the inverted lists for any rotation matching */
+	if (invert_elist(s, &s->ixelist, &s->xelist))
+		return 1;
+	if (invert_elist(s, &s->iyelist, &s->yelist))
+		return 1;
+
+	if (s->verb >= 3) {
+		DBG((dbgo,"\nxelist:\n"));
+		debug_elist(s,&s->xelist);
+		DBG((dbgo,"\nixelist:\n"));
+		debug_elist(s,&s->ixelist);
+		DBG((dbgo,"\nyelist:\n"));
+		debug_elist(s,&s->yelist);
+		DBG((dbgo,"\niyelist:\n"));
+		debug_elist(s,&s->iyelist);
+	}
+
+	/* Clean up */
+	free(xl.a);
+	free(yl.a);
+	free(tl.a);
+	return 0;
+}
+
+/********************************************************************************/
+/* Write the elists out to a file */
+
+/* Increment a string counter */
+static void
+strinc(
+char *s
+) {
+	int i,n,c;	/* Length of string and carry flag */
+	n = strlen(s);
+	for (c = 1, i = n-1; i >= 0 && c != 0; i--) {
+		char sval = ' ';
+		if (s[i] == '9') {
+			s[i] = '0';
+			sval = '1';
+			c = 1;
+		} else if (s[i] == 'z') {
+			s[i] = 'a';
+			sval = 'a';
+			c = 1;
+		} else if (s[i] == 'Z') {
+			s[i] = 'A';
+			sval = 'A';
+			c = 1;
+		} else {
+			s[i]++;
+			c = 0;
+		}
+		if (i == 0 && c != 0) {
+			/* Assume there is some more space */
+			for (i = n; i >= 0; i--)
+				s[i+1] = s[i];
+			s[0] = sval;
+			break;
+		}
+	}
+}
+
+/* Write out the match reference information */
+/* Return non-zero on error */
+static int
+write_elists(
+scanrd_ *s
+) {
+	char *fname = s->refname;			/* Path of file to write to */
+	FILE *elf;
+	int i;
+
+	if ((elf=fopen(fname,"w"))==NULL) {
+		s->errv = SI_REF_WRITE_ERR;
+		sprintf(s->errm,"write_elists: error opening match reference file '%s'",fname);
+		return 1;
+	}
+
+	fprintf(elf,"REF_ROTATION %f\n\n",DEG(s->irot));
+
+	fprintf(elf,"XLIST %d\n",s->xelist.c);
+	for (i = 0; i < s->xelist.c; i++)
+		fprintf(elf,"  %f %f %f\n",s->xelist.a[i].pos, s->xelist.a[i].len, s->xelist.a[i].ccount);
+	fprintf(elf,"\n");
+
+	fprintf(elf,"YLIST %d\n",s->yelist.c);
+	for (i = 0; i < s->yelist.c; i++)
+		fprintf(elf,"  %f %f %f\n",s->yelist.a[i].pos, s->yelist.a[i].len, s->yelist.a[i].ccount);
+	fprintf(elf,"\n");
+
+	if ((fclose(elf)) == EOF) {
+		s->errv = SI_REF_WRITE_ERR;
+		error("write_elists: Unable to close match reference file '%s'\n",fname);
+		return 1;
+	}
+	return 0;
+}
+
+/* Read in an elist reference file */
+/* return non-zero on error */
+/* (~~~ the line counting is rather broken ~~~) */
+static int
+read_relists(
+scanrd_ *s
+) {
+	char *fname = s->refname;			/* Path of file to read from */
+	FILE *elf;
+	int i,l = 1;
+	int rv;
+	char *em;	/* Read error message */
+
+	if ((elf=fopen(fname,"r"))==NULL) {
+		s->errv = SI_REF_READ_ERR;
+		sprintf(s->errm,"read_elists: error opening match reference file '%s'",fname);
+		return 1;
+	}
+
+	s->fid[0] = s->fid[1] = 0.0;
+	s->fid[2] = s->fid[3] = 0.0;
+	s->fid[4] = s->fid[5] = 0.0;
+	s->fid[6] = s->fid[7] = 0.0;
+
+	/* BOXES */
+	for(;;) {
+		if((rv = fscanf(elf,"BOXES %d",&s->nsbox)) == 1) {
+			l++;
+			break;
+		}
+		if (rv == EOF) {
+			em = "Didn't find BOXES before end of file";
+			goto read_error;
+		}
+		if (rv == 0) {
+			while ((rv = getc(elf)) != '\n' && rv != EOF);
+			l++;
+		}
+	}
+
+	/* Allocate structures for boxes */
+	if ((s->sboxes = (sbox *) calloc(s->nsbox, sizeof(sbox))) == NULL) {
+		s->errv = SI_MALLOC_REFREAD;
+		sprintf(s->errm,"read_elist, malloc failed");
+		return 1;
+	}
+	for (i = 0; i < s->nsbox;) {
+		char xfix1[20], xfix2[20], yfix1[20],yfix2[20];
+		char xfirst[20];
+		double ox,oy,w,h,xi,yi;
+		char xf[20];
+		double x;
+
+		if(fscanf(elf," %19s %19s %19s %19s %19s %lf %lf %lf %lf %lf %lf",xfirst ,xfix1, xfix2, yfix1, yfix2, &w, &h, &ox, &oy, &xi, &yi) != 11) {
+			em = "Read of BOX failed";
+			goto read_error;
+		}
+		l++;
+
+		/* If Fiducial. Typically top left, top right, botton right, bottom left. */
+		if (xfirst[0] == 'F') {
+			s->fid[0] = atof(yfix1);
+			s->fid[1] = atof(yfix2);
+			s->fid[2] = w;
+			s->fid[3] = h;
+			s->fid[4] = ox;
+			s->fid[5] = oy;
+			s->fid[6] = xi;
+			s->fid[7] = yi;
+			s->fidsize = fabs(s->fid[2] - s->fid[0]) + fabs(s->fid[5] - s->fid[3]);
+			s->fidsize /= 80.0;
+			s->havefids = 1;
+
+//printf("~1 fiducials %f %f, %f %f %f, %f\n",w, h, ox,oy, xi, yi);
+			continue;
+		}
+		for(;;) {		/* Do Y increment */
+			x = ox;
+			strcpy(xf,xfix1);
+			for(;;) {	/* Do X increment */
+				if (i >= s->nsbox) {
+					em = "More BOXes that declared";
+					goto read_error;
+				}
+				/* '_' is used as a null string marker for single character single cells */
+				if (xf[0] == '_')
+					sprintf(s->sboxes[i].name,"%s",yfix1);
+				else if (yfix1[0] == '_')
+					sprintf(s->sboxes[i].name,"%s",xf);
+				else {	/* Y indicates Y name comes first */
+					if (xfirst[0] == 'Y')
+						sprintf(s->sboxes[i].name,"%s%s",yfix1,xf);
+					else	/* X or D */
+						sprintf(s->sboxes[i].name,"%s%s",xf,yfix1);
+				}
+				if (xfirst[0] == 'D')
+					s->sboxes[i].diag = 1;	/* Diagnostic box - don't print name or read pixels */
+				else
+					s->sboxes[i].diag = 0;
+				s->sboxes[i].x1 = x;
+				s->sboxes[i].y1 = oy;
+				s->sboxes[i].x2 = x + w;
+				s->sboxes[i].y2 = oy + h;
+
+				/* Misc. init. of new sbox */
+				s->sboxes[i].xpt[0] = -1.0;		/* No default expected value */
+				
+				i++;
+				x += xi;
+				if (strcmp(xf,xfix2) == 0)
+					break;
+				strinc(xf);
+				}
+			if (strcmp(yfix1,yfix2) == 0)
+				break;
+			oy += yi;
+			strinc(yfix1);
+		}
+	}
+
+	/* BOX_SHRINK */
+	for(;;) {
+		if((rv = fscanf(elf,"BOX_SHRINK %lf ",&s->rbox_shrink)) == 1) {
+			l++;
+			break;
+		}
+		if (rv == EOF) {
+			em = "Didn't find BOX_SHRINK before end of file";
+			goto read_error;
+		}
+		if (rv == 0) {
+			while ((rv = getc(elf)) != '\n' && rv != EOF); 
+			l++;
+		}
+	}
+
+	/* XLIST */
+	for(;;) {
+		if((rv = fscanf(elf,"XLIST %d ",&s->rxelist.c)) == 1) {
+			l++;
+			break;
+		}
+		if (rv == EOF) {
+			em = "Didn't find XLIST before end of file";
+			goto read_error;
+		}
+		if (rv == 0) {
+			while ((rv = getc(elf)) != '\n' && rv != EOF);
+			l++;
+		}
+	}
+	/* Allocate structures for ref edge lists */
+	if ((s->rxelist.a = (epoint *) malloc(sizeof(epoint) * s->rxelist.c)) == NULL) {
+		s->errv = SI_MALLOC_REFREAD;
+		sprintf(s->errm,"read_elist, malloc failed");
+		return 1;
+	}
+	for (i = 0; i < s->rxelist.c; i++) {
+		if (fscanf(elf," %lf %lf %lf ",
+		    &s->rxelist.a[i].pos, &s->rxelist.a[i].len, &s->rxelist.a[i].ccount) != 3) {
+			em = "Failed to read an XLIST line";
+			goto read_error;
+		}
+		l++;
+	}
+
+	/* YLIST */
+	for(;;) {
+		if ((rv = fscanf(elf,"YLIST %d ",&s->ryelist.c)) == 1) {
+			l++;
+			break;
+		}
+		if (rv == EOF) {
+			em = "Didn't find YLIST before end of file";
+			goto read_error;
+		}
+		if (rv == 0) {
+			while ((rv = getc(elf)) != '\n' && rv != EOF);
+			l++;
+		}
+	}
+	if ((s->ryelist.a = (epoint *) malloc(sizeof(epoint) * s->ryelist.c)) == NULL) {
+		s->errv = SI_MALLOC_REFREAD;
+		sprintf(s->errm,"read_elist, malloc failed");
+		return 1;
+	}
+	for (i = 0; i < s->ryelist.c; i++) {
+		if (fscanf(elf," %lf %lf %lf ",
+		    &s->ryelist.a[i].pos, &s->ryelist.a[i].len, &s->ryelist.a[i].ccount) != 3)
+			{
+			em = "Failed to read an YLIST line";
+			goto read_error;
+		}
+		l++;
+	}
+
+	/* EXPECTED */
+	{
+		int j;
+		int isxyz = 0;
+		int nxpt = 0;
+		char csps[20];
+
+		for(;;) {
+			if ((rv = fscanf(elf,"EXPECTED %19s %d ",csps, &nxpt)) == 2) {
+				l++;
+				if (strcmp(csps, "XYZ") == 0) {
+					isxyz = 1;
+					break;
+				} else if (strcmp(csps, "LAB") == 0) {
+					isxyz = 0;
+					break;
+				} else {
+					em = "Unknown EXPECTED colorespace";
+					goto read_error;
+				}
+			}
+			if (rv == EOF) {
+				break;
+			}
+			if (rv == 0) {
+				while ((rv = getc(elf)) != '\n' && rv != EOF);
+				l++;
+			}
+		}
+		for (j = 0; j < nxpt; j++) {
+			char name[20];
+			double val[3];
+			if (fscanf(elf," %19s %lf %lf %lf ",
+			    name, &val[0], &val[1], &val[2]) != 4)
+				{
+				em = "Failed to read an EXPECTED line";
+				goto read_error;
+			}
+			l++;
+			/* Now locate the matching box */
+			for (i = 0; i < s->nsbox; i++) {
+				if (strcmp(s->sboxes[i].name, name) == 0) {	/* Found it */
+					if (isxyz) {
+						XYZ2Lab(s->sboxes[i].xpt, val);
+					} else {
+						s->sboxes[i].xpt[0] = val[0];
+						s->sboxes[i].xpt[1] = val[1];
+						s->sboxes[i].xpt[2] = val[2];
+					}
+					s->xpt = 1;
+					break;
+				}
+			}
+			if (i >= s->nsbox) {
+				em = "Failed to locate matching sample box in EXPECTED list";
+				goto read_error;
+			}
+		}
+	}
+
+	if ((fclose(elf)) == EOF) {
+		s->errv = SI_REF_WRITE_ERR;
+		error("read_elists: Unable to close match reference file '%s'\n",fname);
+		return 1;
+	}
+
+	/* Generate length normalization factor */
+	{
+		double tlen;	/* Total of normalized length */
+		for (tlen = 0.0, i=0; i < s->rxelist.c; i++)
+			tlen += s->rxelist.a[i].len;
+		s->rxelist.lennorm = tlen;
+		for (tlen = 0.0, i=0; i < s->ryelist.c; i++)
+			tlen += s->ryelist.a[i].len;
+		s->ryelist.lennorm = tlen;
+	}
+
+	if (s->verb >= 3) {
+		DBG((dbgo,"\nrxelist:\n"));
+		debug_elist(s, &s->rxelist);
+		DBG((dbgo,"\nryelist:\n"));
+		debug_elist(s, &s->ryelist);
+	}
+
+	return 0;
+
+read_error:;
+	s->errv = SI_REF_FORMAT_ERR;
+	sprintf(s->errm,"read_relist failed at line %d in file %s: %s\n",l,fname,em);
+	return 1;
+}
+
+/********************************************************************************/
+/* Create an inverted direction elist */
+/* return non-zero on error */
+static int
+invert_elist(
+scanrd_ *s,
+elist *dl,		/* Destination list */
+elist *sl		/* Source list */
+) {
+	int i,j, rc = sl->c;
+	
+	*dl = *sl;	/* Copy all the structure elements */
+
+	/* Allocate space in the destination list */
+	if ((dl->a = (epoint *) malloc(sizeof(epoint) * rc)) == NULL) {
+		s->errv = SI_MALLOC_ELIST;
+		sprintf(s->errm,"invert_elist: malloc failed");
+		return 1;
+	}
+
+	/* Copy the array data and reverse its order */
+	for (i = 0, j = rc-1; i < rc; i++,j--) {
+		dl->a[j]  = sl->a[i];		/* Copy array element */
+		dl->a[j].pos = -dl->a[j].pos;	/* Invert position */
+	}
+	return 0;
+}
+
+/* Print out elist */
+static void
+debug_elist(
+scanrd_ *s,
+elist *el
+) {
+	int i, rc = el->c;
+	
+	DBG((dbgo,"Elist has %d entries allocated at 0x%p\n",el->c,el->a));
+	DBG((dbgo,"lennorm = %f\n",el->lennorm));
+	for (i = 0; i < rc; i++)
+		DBG((dbgo,"  [%d] = %f %f %f\n",i,el->a[i].pos,el->a[i].len,el->a[i].ccount));
+}
+
+/* Free the array data in an elist */
+static void
+free_elist_array(elist *el) {
+	free(el->a);
+	el->c = 0;
+}
+
+/********************************************************************************/
+/* !!!!!!! */
+/* NEED TO RESOLVE WHY current code is better in some cases, but */
+/* not in others. */
+
+#ifndef NEVER	/* Current code */
+
+/* Compute a correlation between two elists */
+static double
+elist_correl(
+scanrd_ *s,
+elist *r,		/* Reference list */
+elist *t,		/* Target list */
+double off, double scale,		/* Offset and scale of target to ref */
+int verb		/* Verbose mode */
+) {
+	int i, j, rc = r->c;
+	double cc = 0.0;		/* Correlation */
+	double marg = (r->a[rc-1].pos - r->a[0].pos)/150.0;	/* determines sharpness of pos. match */
+	double marg2 = marg * 3.0;		/* Don't contribute anything outside this distance */
+	
+	for (i = j = 0; i < t->c; i++) {
+		int ri;		/* Reference index */
+		double dd,d1,d2;		/* Distance to nearest reference */
+		double pos = (t->a[i].pos + off) * scale;
+		double len = t->a[i].len;
+		double cnt = t->a[i].ccount;
+		while (pos > r->a[j+1].pos && j < (r->c-2)) j++;
+		d1 = fabs(pos - r->a[j].pos);
+		d2 = fabs(r->a[j+1].pos - pos);
+		if (d1 < d2) {
+			dd = d1;
+			ri = j;
+		} else {
+			dd = d2;
+			ri = j+1;
+		}
+		if (dd <= marg2) {	/* If close enough to reference */
+			double ccf, rcnt = r->a[ri].ccount;
+			double llf, rlen = r->a[ri].len;
+			double df = marg/(marg + dd);
+			df *= df;
+			ccf = 1.0 - (rcnt > cnt ? rcnt-cnt : cnt-rcnt);
+			llf = 1.0 - (rlen > len ? rlen-len : len-rlen);
+			/* The weighting gives slightly more emphasis on matching long lines */
+			cc += (1.0 + rlen) * (df * llf * ccf);
+			if (verb) {
+				DBG((dbgo,"---- t[%d] %f %f %f    this cc = %f, running total cc = %f\n     r[%d] %f %f %f, df = %f, llf = %f, ccf = %f\n",
+				i,pos,len,cnt,df * llf * ccf,cc,j,r->a[ri].pos,r->a[ri].len,rcnt,df, llf, ccf));
+			}
+		}
+	}
+	return cc/(r->lennorm + (double)r->c);		/* Normalize */
+}
+
+#else	/* New test code */
+
+/* Compute a correlation between two elists */
+static double
+elist_correl(
+scanrd_ *s,
+elist *r,		/* Reference list */
+elist *t,		/* Target list */
+double off, double scale,		/* Offset and scale of target to ref */
+int verb		/* Verbose mode */
+) {
+	int i, rc = r->c;
+	double cc = 0.0;		/* Correlation */
+	double marg = (r->a[rc-1].pos - r->a[0].pos)/100.0;	/* determines sharpness of pos. match */
+	double marg2 = marg * marg;		/* marg squared */
+	
+//printf("~1 doing elist_correl\n");
+	/* For each reference edge */
+	for (i = 0; i < rc; i++) {
+		int j[3], jj, bj, tc = t->c;
+		double dd, pos, bdd;
+
+		/* Find the closest target edge using binary search. */
+		for(bdd = 1e6, j[2] = tc-1, j[0] = 0; j[2] > (j[0]+1);) {
+			double dist;
+			j[1] = (j[2] + j[0])/2;			/* Trial point */
+			dist = r->a[i].pos - (t->a[j[1]].pos + off) * scale;
+			
+//printf("~1 j1 = %d, j1 = %d, j0 = %d, dist = %f\n",j[2], j[1], j[0], dist);
+			if (dist > 0) {
+				j[0] = j[1];
+			} else {
+				j[2] = j[1];
+			}
+		}
+
+		/* Locate best out of 3 remaining points */
+		for (jj = 0; jj < 3; jj++) {
+			double dist;
+			pos = (t->a[j[jj]].pos + off) * scale;
+			dist = r->a[i].pos - pos;
+			dd = dist * dist;				/* Distance squared */
+			if (dd < bdd) {	/* New closest */
+				bdd = dd;
+				bj = j[jj];
+			}
+		}
+
+//printf("~1 best j = %d, bdd = %f, marg2 = %f\n",bj,bdd,marg2);
+		/* Compute correlation */
+		if (bdd < marg2) {		/* Within our margine */
+			double df = (marg2 - bdd)/marg2;		/* Distance factor */
+			double llf, rlen = r->a[i].len, len = t->a[i].len;
+			double ccf, rcnt = r->a[i].ccount, cnt = t->a[i].ccount;
+			double tcc;
+			llf = 1.0 - (rlen > len ? rlen-len : len-rlen);
+			ccf = 1.0 - (rcnt > cnt ? rcnt-cnt : cnt-rcnt);
+
+			/* The weighting gives slightly more emphasis on matching long lines */
+			/* Not using crossing count */
+			tcc = (1.0 + rlen) * (df * llf);
+			cc += tcc;
+			if (verb) {
+				DBG((dbgo,"---- targ[%d] %f %f %f    this cc = %f, running total cc = %f\n",
+				bj,pos,t->a[bj].len,t->a[bj].ccount, tcc,cc));
+				DBG((dbgo,"      ref[%d] %f %f %f, df = %f, llf = %f, ccf = %f\n",
+				i,r->a[i].pos,r->a[i].len,r->a[i].ccount, df, llf, ccf));
+			}
+		}
+
+	}
+	return cc/(r->lennorm + (double)r->c);		/* Normalize */
+}
+
+#endif /* NEVER */
+
+/* Structure to hold data for optimization function */
+struct _edatas {
+	scanrd_ *s;		/* scanrd object */
+	elist *r;		/* Reference list */
+	elist *t;		/* Target list */
+	int verb;		/* Verbose mode */
+	}; typedef struct _edatas edatas;
+
+/* Definition of the optimization function handed to powell() */
+static double
+efunc(void *edata, double p[]) {
+	edatas *e = (edatas *)edata;
+	double rv = 2.0 - elist_correl(e->s,e->r,e->t,p[0],p[1],e->verb);
+	return rv;
+}
+
+/* return non-zero on error */
+static int
+best_match(
+scanrd_ *s,
+elist *r,		/* Reference list */
+elist *t,		/* Target list */
+ematch *rv		/* Return values */
+) {
+	int r0,r1,rw,t0,t1;
+	double rwidth;
+	double cc;
+	double bcc = 0.0, boff = 0.0, bscale = 0.0;	/* best values */
+	
+	/* The target has been rotated, and we go through all reasonable */
+	/* translations and scales to see if we can match it to the */
+	/* reference. */
+	r0 = 0;
+	r1 = r->c-1;
+	rw = r->c/2;	/* Minimum number of target line to match all of reference */
+	if (t->c/2 < rw)
+		rw = t->c/2;
+	rwidth = r->a[r1].pos - r->a[r0].pos;
+
+	for (t0 = 0; t0 < t->c-1; t0++) {
+		double off;
+		for (t1 = t->c-1; t1 > (t0+rw); t1--) {
+			double scale;
+
+			scale = rwidth/(t->a[t1].pos - t->a[t0].pos);
+			if (scale < 0.001 || scale > 100.0) {
+				break;		/* Don't bother with silly scale factors */
+			}
+
+			/* Have to compenate the offset for the scale since it is scaled from 0 */
+			off = r->a[r0].pos/scale - t->a[t0].pos;
+	        cc = elist_correl(s,r,t,off,scale,0);
+
+			if (s->verb >= 7) {
+				DBG((dbgo,"Matching target [%d]-[%d] to ref [%d]-[%d] = %f-%f to %f-%f\n",
+		   			t0,t1,r0,r1,t->a[t0].pos,t->a[t1].pos,r->a[r0].pos,r->a[r1].pos));
+				DBG((dbgo,"Initial off %f, scale %f, cc = %f\n",off,scale,cc));
+			}
+			if (cc > 0.20) {	/* Looks promising, try optimizing solution */
+				double cp[2];	/* Start point/improved point */
+				double rv;		/* Return value */
+				int rc;			/* Return code */
+				edatas dd;		/* Data structure */
+				double ss[2] = { 0.1, 0.1};	/* Initial search distance */
+				
+				dd.s = s;	/* scanrd object */
+				dd.r = r;	/* Reference list */
+				dd.t = t;	/* Target list */
+				dd.verb = 0;		/* Verbose mode */
+
+				/* Set search start point */
+				cp[0] = off;
+				cp[1] = scale;
+				/* Set search distance */
+				ss[0] = (0.01 * rwidth/ELISTCDIST)/scale;	/* Search distance */
+				ss[1] = scale * 0.01 * rwidth/ELISTCDIST;
+
+				/* Find minimum */
+				rc = powell(&rv, 2,cp,ss,0.0001,400,efunc,&dd, NULL, NULL);
+
+				if (rc == 0								/* Powell converged */
+				  && cp[1] > 0.001 && cp[1] < 100.0) {	/* and not ridiculous */
+					cc = 2.0 - rv;
+					off = cp[0];
+					scale = cp[1];
+				} 
+				/* Else use unoptimsed values */
+
+				if (s->verb >= 7) {
+					DBG((dbgo,"After optimizing, off %f, scale %f, cc = %f\n",off,scale,cc));
+				}
+			}
+
+			if (s->verb >= 7) {
+				if (cc > 0.25) {
+					DBG((dbgo,"Good correlation::\n"));
+					elist_correl(s,r,t,off,scale,1);
+				}
+			}
+			if (s->verb >= 7)
+				DBG((dbgo,"offset %f, scale %f cc %f\n", off,scale,cc));
+	        if (cc > 0.0 && cc > bcc) {	/* Keep best */
+				boff = off;
+				bscale = scale;
+				bcc = cc;
+				if (s->verb >= 7)
+					DBG((dbgo,"(New best)\n"));
+			}
+		}
+	}
+	if (s->verb >= 7)
+		DBG((dbgo,"Returning best offset %f, scale %f returns %f\n\n", boff,bscale,bcc));
+
+	/* return best values */
+	rv->cc = bcc;
+	rv->off = boff;
+	rv->scale = bscale;
+	return 0;
+}
+
+/* Find best offset and scale match between reference and target, */
+/* and then from this, compute condidate 90 degree rotations. */
+/* Return 0 if got at least one candidate rotation */
+/* Return 1 if no reasonable candidate rotation found */
+/* Return 2 if some other error */
+static int
+do_match(
+scanrd_ *s
+) {
+	ematch  xx, yy, xy, yx, xix, yiy, xiy, yix;	/* All 8 matches needed to detect rotations */
+	double r0, r90, r180, r270;			/* Correlation for each extra rotation of target */
+
+	/* Check out all the matches */
+	if (s->verb >= 2) DBG((dbgo,"Checking xx\n"));
+	if (best_match(s, &s->rxelist,&s->xelist,&xx))
+		return 2;
+	if (s->verb >= 2) DBG((dbgo,"Checking yy\n"));
+	if (best_match(s, &s->ryelist,&s->yelist,&yy))
+		return 2;
+	if (s->verb >= 2) DBG((dbgo,"Checking xy\n"));
+	if (best_match(s, &s->rxelist,&s->yelist,&xy))
+		return 2;
+	if (s->verb >= 2) DBG((dbgo,"Checking yx\n"));
+	if (best_match(s, &s->ryelist,&s->xelist,&yx))
+		return 2;
+	if (s->verb >= 2) DBG((dbgo,"Checking xix\n"));
+	if (best_match(s, &s->rxelist,&s->ixelist,&xix))
+		return 2;
+	if (s->verb >= 2) DBG((dbgo,"Checking yiy\n"));
+	if (best_match(s, &s->ryelist,&s->iyelist,&yiy))
+		return 2;
+	if (s->verb >= 2) DBG((dbgo,"Checking xiy\n"));
+	if (best_match(s, &s->rxelist,&s->iyelist,&xiy))
+		return 2;
+	if (s->verb >= 2) DBG((dbgo,"Checking yix\n"));
+	if (best_match(s, &s->ryelist,&s->ixelist,&yix))
+		return 2;
+
+	if (s->verb >= 2) {
+		DBG((dbgo,"Axis matches for each possible orientation:\n"));
+		DBG((dbgo,"  0: xx  = %f, yy  = %f, xx.sc  = %f, yy.sc  = %f\n",
+		                                xx.cc,yy.cc,xx.scale,yy.scale));
+		DBG((dbgo," 90: xiy = %f, yx  = %f, xiy.sc = %f, yx.sc  = %f\n",
+		                                xiy.cc,yx.cc,xiy.scale,yx.scale));
+		DBG((dbgo,"180: xix = %f, yiy = %f, xix.sc = %f, yiy.sc = %f\n",
+		                                xix.cc,yiy.cc,xix.scale,yiy.scale));
+		DBG((dbgo,"270: xy  = %f, yix = %f, xy.sc  = %f, yix.sc = %f\n",
+		                                xy.cc,yix.cc,xy.scale,yix.scale));
+	}
+
+	/* Compute the combined values for the four orientations. */
+	/* add penalty for different scale factors */
+	r0   = sqrt(xx.cc * xx.cc + yy.cc * yy.cc)
+	     * (xx.scale > yy.scale ? yy.scale/xx.scale : xx.scale/yy.scale);
+	r90  = sqrt(xiy.cc * xiy.cc + yx.cc * yx.cc)
+	     * (xiy.scale > yx.scale ? yx.scale/xiy.scale : xiy.scale/yx.scale);
+	r180 = sqrt(xix.cc * xix.cc + yiy.cc * yiy.cc)
+	     * (xix.scale > yiy.scale ? yiy.scale/xix.scale : xix.scale/yiy.scale);
+	r270 = sqrt(xy.cc * xy.cc + yix.cc * yix.cc)
+	     * (xy.scale > yix.scale ? yix.scale/xy.scale : xy.scale/yix.scale);
+
+	if (s->verb >= 2)
+		DBG((dbgo,"r0 = %f, r90 = %f, r180 = %f, r270 = %f\n",r0,r90,r180,r270));
+
+	s->norots = 0;
+	if (s->flags & SI_GENERAL_ROT) { /* If general rotation allowed */
+		if (s->xpt == 0) {		/* No expected color information to check rotations agaist */
+								/* so choose the single best rotation by the edge matching */
+			DBG((dbgo,"There is no expected color information, so best fit rotations will be used\n"));
+			if (r0 >= MATCHCC && r0 >= r90 && r0 >= r180 && r0 >= r270) {
+				s->rots[0].ixoff   = -xx.off; 
+				s->rots[0].ixscale = 1.0/xx.scale;
+				s->rots[0].iyoff   = -yy.off;
+				s->rots[0].iyscale = 1.0/yy.scale;
+				s->rots[0].irot    = s->irot;
+				s->rots[0].cc      = r0;
+				s->norots = 1;
+			} else if (r90 >= MATCHCC && r90 >= r180 && r90 >= r270) {
+				s->rots[0].ixoff   = -xiy.off;
+				s->rots[0].ixscale = 1.0/xiy.scale;
+				s->rots[0].iyoff   = -yx.off;
+				s->rots[0].iyscale = 1.0/yx.scale;
+				s->rots[0].irot    = s->irot + M_PI_2;
+				s->rots[0].cc      = r90;
+				s->norots = 1;
+			} else if (r180 >= MATCHCC && r180 >= r270) {
+				s->rots[0].ixoff   = -xix.off;
+				s->rots[0].ixscale = 1.0/xix.scale;
+				s->rots[0].iyoff   = -yiy.off;
+				s->rots[0].iyscale = 1.0/yiy.scale;
+				s->rots[0].irot    = s->irot + M_PI;
+				s->rots[0].cc      = r180;
+				s->norots = 1;
+			} else if (r270 >= MATCHCC) {	/* 270 extra target rotation */
+				s->rots[0].ixoff   = -xy.off;
+				s->rots[0].ixscale = 1.0/xy.scale;
+				s->rots[0].iyoff   = -yix.off;
+				s->rots[0].iyscale = 1.0/yix.scale;
+				s->rots[0].irot    = s->irot + M_PI + M_PI_2;
+				s->rots[0].cc      = r270;
+				s->norots = 1;
+			}
+
+		} else {	/* Got expected color info, so try reasonable rotations */
+			double bcc;		/* Best correlation coeff */
+
+			if (r0 >= r90 && r0 >= r180 && r0 >= r270)
+				bcc = r0;
+			else if (r90 >= r180 && r90 >= r270)
+				bcc = r90;
+			else if (r180 >= r270)
+				bcc = r180;
+			else 
+				bcc = r270;
+
+			bcc *= ALT_ROT_TH;		/* Threshold for allowing alternate rotation */
+			if (bcc < MATCHCC)
+				bcc = MATCHCC;
+
+			s->norots = 0;
+			if (r0 >= bcc) {
+				s->rots[s->norots].ixoff   = -xx.off; 
+				s->rots[s->norots].ixscale = 1.0/xx.scale;
+				s->rots[s->norots].iyoff   = -yy.off;
+				s->rots[s->norots].iyscale = 1.0/yy.scale;
+				s->rots[s->norots].irot    = s->irot;
+				s->rots[s->norots].cc      = r0;
+				s->norots++;
+			}
+			if (r90 >= bcc) {
+				s->rots[s->norots].ixoff   = -xiy.off;
+				s->rots[s->norots].ixscale = 1.0/xiy.scale;
+				s->rots[s->norots].iyoff   = -yx.off;
+				s->rots[s->norots].iyscale = 1.0/yx.scale;
+				s->rots[s->norots].irot    = s->irot + M_PI_2;
+				s->rots[s->norots].cc      = r90;
+				s->norots++;
+			}
+			if (r180 >= bcc) {
+				s->rots[s->norots].ixoff   = -xix.off;
+				s->rots[s->norots].ixscale = 1.0/xix.scale;
+				s->rots[s->norots].iyoff   = -yiy.off;
+				s->rots[s->norots].iyscale = 1.0/yiy.scale;
+				s->rots[s->norots].irot    = s->irot + M_PI;
+				s->rots[s->norots].cc      = r180;
+				s->norots++;
+			}
+			if (r270 >= bcc) {
+				s->rots[s->norots].ixoff   = -xy.off;
+				s->rots[s->norots].ixscale = 1.0/xy.scale;
+				s->rots[s->norots].iyoff   = -yix.off;
+				s->rots[s->norots].iyscale = 1.0/yix.scale;
+				s->rots[s->norots].irot    = s->irot + M_PI + M_PI_2;
+				s->rots[s->norots].cc      = r270;
+				s->norots++;
+			}
+		}
+	} else {	/* Use only rotation 0 */
+		if (r0 >= MATCHCC) {
+			s->rots[0].ixoff   = -xx.off; 
+			s->rots[0].ixscale = 1.0/xx.scale;
+			s->rots[0].iyoff   = -yy.off;
+			s->rots[0].iyscale = 1.0/yy.scale;
+			s->rots[0].irot    = s->irot;
+			s->rots[0].cc      = r0;
+			s->norots = 1;
+		} else if (s->flags & SI_ASISIFFAIL) {
+			DBG((dbgo, "Recognition failed, reading patches 'as is' (probably incorrect)\n"));
+			s->rots[0].ixoff   = 0.0;
+			s->rots[0].ixscale = 1.0;
+			s->rots[0].iyoff   = 0.0;
+			s->rots[0].iyscale = 1.0;
+			s->rots[0].irot    = 0.0;
+			s->rots[0].cc      = r0;
+			s->norots = 1;
+		}
+	}
+
+	if (s->verb >= 2) {
+		int i;
+		DBG((dbgo,"There are %d candidate rotations:\n",s->norots));
+		
+		for (i = 0; i < s->norots; i++) {
+			DBG((dbgo,"cc = %f, irot = %f, xoff = %f, yoff = %f, xscale = %f, yscale = %f\n",
+		        s->rots[i].cc, DEG(s->rots[i].irot), s->rots[i].ixoff,s->rots[i].iyoff,s->rots[i].ixscale,s->rots[i].iyscale));
+		}
+	}
+
+	if (s->norots == 0)
+		return 1;
+
+	return 0;
+}
+
+/********************************************************************************/
+/* perspective transformation. */
+/* Transform from raster to reference using iptrans[]. */
+/* Transform from reference to raster using ptrans[]. */
+static void ptrans(double *xx, double *yy, double x, double y, double *ptrans) {
+	double den;
+
+	den = ptrans[6] * x + ptrans[7] * y + 1.0;
+
+	if (fabs(den) < 1e-6) {
+		if (den < 0.0)
+			den = -1e-6;
+		else
+			den = 1e-6;
+	}
+
+	*xx = (ptrans[0] * x + ptrans[1] * y + ptrans[2])/den;
+	*yy = (ptrans[3] * x + ptrans[4] * y + ptrans[5])/den;
+}
+
+/* Convert perspective transfom parameters to inverse */
+/* perspective transform parameters. */
+/* Return nz on error */
+int invert_ptrans(double *iptrans, double *ptrans) {
+	double scale = ptrans[0] * ptrans[4] - ptrans[1] * ptrans[3];
+
+	if (fabs(scale) < 1e-6)
+		return 1;
+
+	scale = 1.0/scale;
+
+	iptrans[0] = scale * (ptrans[4] - ptrans[5] * ptrans[7]);
+	iptrans[1] = scale * (ptrans[2] * ptrans[7] - ptrans[1]);
+	iptrans[2] = scale * (ptrans[1] * ptrans[5] - ptrans[2] * ptrans[4]);
+
+	iptrans[3] = scale * (ptrans[5] * ptrans[6] - ptrans[3]);
+	iptrans[4] = scale * (ptrans[0] - ptrans[2] * ptrans[6]);
+	iptrans[5] = scale * (ptrans[2] * ptrans[3] - ptrans[0] * ptrans[5]);
+
+	iptrans[6] = scale * (ptrans[3] * ptrans[7] - ptrans[4] * ptrans[6]);
+	iptrans[7] = scale * (ptrans[1] * ptrans[6] - ptrans[0] * ptrans[7]);
+
+	return 0;
+}
+
+
+/* Structure to hold data for optimization function */
+struct _pdatas {
+	scanrd_ *s;		/* scanrd object */
+	double *tar;	/* 4 x x,y raster points */
+	double *ref;	/* 4 x x,y reference points */
+}; typedef struct _pdatas pdatas;
+
+/* Definition of the optimization function handed to powell() */
+/* We simply want to match the 4 points from the reference */
+/* back to the target raster. */
+static double
+ptransfunc(void *pdata, double p[]) {
+	pdatas *e = (pdatas *)pdata;
+	int i;
+	double rv = 0.0;
+
+	for (i = 0; i < 8; i += 2) {
+		double x, y;
+
+		ptrans(&x, &y, e->ref[i+0], e->ref[i+1], p);
+
+		rv += (e->tar[i+0] - x) * (e->tar[i+0] - x);
+		rv += (e->tar[i+1] - y) * (e->tar[i+1] - y);
+	}
+
+	return rv;
+}
+
+/* Compute a combined perspective transform */
+/* given two sets of four reference points. */
+/* Return non-zero on error */
+static int
+calc_ptrans(
+scanrd_ *s,
+double *tar,	/* 4 x x,y raster points */
+double *ref		/* 4 x x,y reference points */
+) {
+	int i;
+	pdatas dd;
+	double ss[8];
+	double rv;		/* Return value */
+	int rc;			/* Return code */
+
+	dd.s = s;
+	dd.tar = tar;
+	dd.ref = ref;
+
+	s->ptrans[0] = 1.0;
+	s->ptrans[1] = 0.0;
+	s->ptrans[2] = 0.0;
+	s->ptrans[3] = 0.0;
+	s->ptrans[4] = 1.0;
+	s->ptrans[5] = 0.0;
+	s->ptrans[6] = 0.0;
+	s->ptrans[7] = 0.0;
+
+	for (i = 0; i < 8; i++)
+		ss[i] = 0.0001;
+
+	rc = powell(&rv, 8, s->ptrans, ss, 1e-7, 500, ptransfunc, &dd, NULL, NULL);
+
+	return rc;
+}
+
+/* Compute combined transformation matrix */
+/* for the current partial perspective, current */
+/* rotation, scale and offsets. */
+/* Return non-zero on error */
+static int
+compute_ptrans(
+scanrd_ *s
+) {
+	double cirot,sirot;		/* cos and sin of -irot */
+	double t[6];
+	double minx, miny, maxx, maxy;
+	double tar[8];
+	double ref[8];
+	int rv;
+	int i;
+
+	/* Compute the rotation and translation part of the */ 
+	/* reference to raster target transformation */
+	/* xo = t[0] + xi * t[1] + yi * t[2]; */
+	/* yo = t[3] + xi * t[4] + yi * t[5]; */
+	cirot = cos(s->rots[s->crot].irot);
+	sirot = sin(s->rots[s->crot].irot);
+	t[0] = cirot * s->rots[s->crot].ixoff + sirot * s->rots[s->crot].iyoff;
+	t[1] = s->rots[s->crot].ixscale * cirot;
+	t[2] = s->rots[s->crot].iyscale * sirot;
+
+	t[3] = -sirot * s->rots[s->crot].ixoff + cirot * s->rots[s->crot].iyoff;
+	t[4] = s->rots[s->crot].ixscale * -sirot;
+	t[5] = s->rots[s->crot].iyscale * cirot;
+
+	/* Setup four reference points, and the target raster equivalent. */
+	/* Choose min/max of matching boxes as test points, to scale with raster size. */
+	minx = miny = 1e60;
+	maxx = maxy = -1e60;
+	for (i = 0; i < s->nsbox; i++) {
+		if (s->sboxes[i].x1 < minx)
+			minx = s->sboxes[i].x1;
+		if (s->sboxes[i].x2 > maxx)
+			maxx = s->sboxes[i].x2;
+		if (s->sboxes[i].y1 < miny)
+			miny = s->sboxes[i].y1;
+		if (s->sboxes[i].y2 > maxy)
+			maxy = s->sboxes[i].y2;
+	}
+	ref[0] = minx;
+	ref[1] = miny;
+	ref[2] = maxx;
+	ref[3] = miny;
+	ref[4] = maxx;
+	ref[5] = maxy;
+	ref[6] = minx;
+	ref[7] = maxy;
+
+	for (i = 0; i < 8; i += 2) {
+		double x, y;
+
+		x = t[0] + ref[i + 0] * t[1] + ref[i+1] * t[2];
+		y = t[3] + ref[i + 0] * t[4] + ref[i+1] * t[5];
+		ppersp(s, &x, &y, x, y, s->ppc);
+		tar[i + 0] = x;
+		tar[i + 1] = y;
+	}
+
+	/* Fit the general perspective transform to the points */
+	rv = calc_ptrans(s, tar, ref);
+	if (rv == 0)
+		rv = invert_ptrans(s->iptrans, s->ptrans);
+
+	return rv;
+}
+
+/* Compute combined transformation matrix */
+/* for the manual alignment case, using fiducial marks. */
+/* Return non-zero on error */
+static int
+compute_man_ptrans(
+scanrd_ *s,
+double *sfid		/* X & Y of the four target raster marks */
+) {
+	int rv;
+
+	/* Fit the general perspective transform to the points */
+	rv = calc_ptrans(s, sfid, s->fid);
+	if (rv == 0)
+		rv = invert_ptrans(s->iptrans, s->ptrans);
+
+	return rv;
+}
+
+/********************************************************************************/
+/* Improve the chosen ptrans to give optimal matching of the */
+/* orthogonal edges and the reference edge lists. */
+
+/* Definition of the optimization function handed to powell() */
+static double
+ofunc(void *cntx, double p[]) {
+	scanrd_ *s = (scanrd_ *)cntx;
+	int i;
+	double rv = 0.0;
+
+	/* First the X list */
+	for (i = 0; i < s->rxelist.c; i++) {
+		points *tp;
+
+		if (s->rxelist.a[i].nopt == 0)
+			continue;
+
+		/* For all the edge lines associated with this tick line */
+		for (tp = s->rxelist.a[i].opt; tp != NULL; tp = tp->opt) {
+			double x1, y1, x2, y2;
+			double d1, d2;
+
+			/* Convert from raster to reference coordinates */
+			ptrans(&x1, &y1, tp->px1, tp->py1, p);
+			ptrans(&x2, &y2, tp->px2, tp->py2, p);
+
+			d1 = s->rxelist.a[i].pos - x1;
+			d2 = s->rxelist.a[i].pos - x2;
+			rv += tp->len * (d1 * d1 + d2 * d2); 
+		}
+	}
+
+	/* Then the Y list */
+	for (i = 0; i < s->ryelist.c; i++) {
+		points *tp;
+
+		if (s->ryelist.a[i].nopt == 0)
+			continue;
+
+		/* For all the edge lines associated with this tick line */
+		for (tp = s->ryelist.a[i].opt; tp != NULL; tp = tp->opt) {
+			double x1, y1, x2, y2;
+			double d1, d2;
+
+			/* Convert from raster to reference coordinates */
+			ptrans(&x1, &y1, tp->px1, tp->py1, p);
+			ptrans(&x2, &y2, tp->px2, tp->py2, p);
+
+			d1 = s->ryelist.a[i].pos - y1;
+			d2 = s->ryelist.a[i].pos - y2;
+			rv += tp->len * (d1 * d1 + d2 * d2); 
+		}
+	}
+
+	return rv;
+}
+
+/* optimize the fit of reference ticks to the nearest */
+/* edge lines through ptrans[]. */
+/* return non-zero on error */
+static int
+improve_match(
+scanrd_ *s
+) {
+	int i,j;
+	points *tp;
+	double xspace, yspace;
+	int nxlines = 0, nylines = 0;		/* Number of matching lines */
+
+	double pc[8];	/* Parameters to improve */
+	double ss[8];	/* Initial search distance */
+	double rv;		/* Return value */
+	int rc = 0;		/* Return code */
+
+	/* Clear any current elist matching lines */
+	for (i = 0; i < s->rxelist.c; i++) {
+		s->rxelist.a[i].opt = NULL;
+		s->rxelist.a[i].nopt = 0;
+	}
+	for (i = 0; i < s->ryelist.c; i++) {
+		s->ryelist.a[i].opt = NULL;
+		s->ryelist.a[i].nopt = 0;
+	}
+
+	/* Figure out the average tick spacing for each reference edge list. */
+	/* (We're assuming the edge lists are sorted) */
+	xspace = (s->rxelist.a[s->rxelist.c-1].pos - s->rxelist.a[0].pos)/s->rxelist.c;
+	yspace = (s->ryelist.a[s->ryelist.c-1].pos - s->ryelist.a[0].pos)/s->ryelist.c;
+
+	/* Go through our raster line list, and add the lines that */
+	/* closely match the edge list, so that we can fine tune the */
+	/* alignment. */
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		if (tp->flag & F_VALID) {
+			double x1, y1, x2, y2;
+			elist *el;
+			double v1, v2;
+			double bdist;
+			int bix;
+			double space;
+			int *nlines = NULL;
+			double a;
+
+			/* Convert from raster to reference coordinates */
+			ptrans(&x1, &y1, tp->px1, tp->py1, s->iptrans);
+			ptrans(&x2, &y2, tp->px2, tp->py2, s->iptrans);
+
+			/* Compute the angle */
+			a = atan2(y2 - y1,x2 - x1);
+
+			/* Constrain the angle to be between -PI/4 and 3PI/4 */
+			if (a < -M_PI_4)
+				a += M_PI;
+			if (a > M_PI_3_4)
+				a -= M_PI;
+
+			/* Decide if it is one of the orthogonal lines */
+			if (fabs(a - M_PI_2) > (0.2 * M_PI_2)		/* 0.2 == +/- 18 degrees */	
+			 && fabs(a - 0.0)    > (0.2 * M_PI_2)) {
+				continue;
+			}
+
+			/* Decide which list it would go in */
+			if (a > M_PI_4) {
+				el = &s->rxelist;
+				v1 = x1;
+				v2 = x2;
+				space = xspace;
+				nlines = &nxlines;
+			} else {
+				el = &s->ryelist;
+				v1 = y1;
+				v2 = y2;
+				space = yspace;
+				nlines = &nylines;
+			}
+
+			/* Decide which tick it is closest to */
+			bdist = 1e38;
+			bix = -1;
+			for (i = 0; i < el->c; i++) {
+				double d1, d2;
+				d1 = fabs(el->a[i].pos - v1);
+				d2 = fabs(el->a[i].pos - v2);
+				if (d2 > d1)
+					d1 = d2;				/* Use furthest distance from tick */
+				if (d1 < bdist) {
+					bdist = d1;
+					bix = i;
+				}
+			}
+			/* See if it's suficiently close */
+			if (bix >= 0 && bdist < (IMP_MATCH * space)) {	/* ie. 0.1 */
+				tp->flag |= F_IMPROVE;
+				if (el->a[bix].opt == NULL) {
+					(*nlines)++;
+				}
+				/* Add it to the linked list of matching lines */
+				tp->opt = el->a[bix].opt;
+				el->a[bix].opt = tp;
+				el->a[bix].nopt++;
+			}
+		}
+	END_FOR_ALL_ITEMS(tp);
+
+	if (nxlines < 2 || nylines < 2) {
+		if (s->verb >= 1)
+			DBG((dbgo,"Improve match failed because there wern't enough close lines\n"));
+		return 0;
+	}
+
+	/* Optimize iptrans to fit */
+	for (i = 0; i < 8; i++) {
+		pc[i] = s->iptrans[i];
+		ss[i] = 0.0001;
+	}
+
+	rc = powell(&rv, 8, pc, ss, 0.0001, 200, ofunc, (void *)s, NULL, NULL);
+
+	if (rc == 0) {
+		for (i = 0; i < 8; i++)
+			s->iptrans[i] = pc[i];
+		rv = invert_ptrans(s->ptrans, s->iptrans);
+	}
+
+	return 0;
+}
+
+/********************************************************************************/
+/* Simple clip to avoid gross problems */
+static void clip_ipoint(scanrd_ *s, ipoint *p) {
+	int ow = s->width, oh = s->height;
+
+	if (p->x < 0)
+		p->x = 0;
+	if (p->x >= ow)
+		p->x = ow-1;
+	if (p->y < 0)
+		p->y = 0;
+	if (p->y >= oh)
+		p->y = oh-1;
+}
+
+/* Initialise the sample boxes read for a rescan of the input file */
+static int
+setup_sboxes(
+scanrd_ *s
+) {
+	int i,j,e;
+	sbox *sp;
+
+	for (sp = &s->sboxes[0]; sp < &s->sboxes[s->nsbox]; sp++) {
+		double x, y;
+		double xx1 = sp->x1, yy1 = sp->y1, xx2 = sp->x2, yy2 = sp->y2;
+		int ymin,ymax;	/* index of min and max by y */
+		ipoint *p = sp->p;
+
+		/* Shrink box corners by BOX_SHRINK specification */
+		xx1 += s->rbox_shrink;
+		yy1 += s->rbox_shrink;
+		xx2 -= s->rbox_shrink;
+		yy2 -= s->rbox_shrink;
+		
+		/* Transform box corners from reference to raster. */
+		/* Box is defined in clockwise direction. */
+		ptrans(&x, &y, xx1, yy1, s->ptrans);
+		p[0].x = (int)(0.5 + x);
+		p[0].y = (int)(0.5 + y);
+		clip_ipoint(s, &p[0]);
+
+		ptrans(&x, &y, xx2, yy1, s->ptrans);
+		p[1].x = (int)(0.5 + x);
+		p[1].y = (int)(0.5 + y);
+		clip_ipoint(s, &p[1]);
+
+		ptrans(&x, &y, xx2, yy2, s->ptrans);
+		p[2].x = (int)(0.5 + x);
+		p[2].y = (int)(0.5 + y);
+		clip_ipoint(s, &p[2]);
+
+		ptrans(&x, &y, xx1, yy2, s->ptrans);
+		p[3].x = (int)(0.5 + x);
+		p[3].y = (int)(0.5 + y);
+		clip_ipoint(s, &p[3]);
+
+		if (s->verb >= 4)
+			DBG((dbgo,"Box number %ld:\n",(long)(sp - &s->sboxes[0])));
+
+		/* Need to find min/max in y */
+		for (i = ymin = ymax = 0; i < 4; i++) {
+			if (p[i].y < p[ymin].y)
+				ymin = i;
+			if (p[i].y > p[ymax].y)
+				ymax = i;
+		}
+		sp->ymin = p[ymin].y;
+		sp->ymax = p[ymax].y;
+		if (s->verb >= 4)
+			DBG((dbgo,"Min y index = %d, value = %d, Max y index = %d, value = %d\n",ymin, sp->ymin, ymax,sp->ymax));
+
+		/* create right side vertex list */
+		for (i = -1, j = ymin;;) {
+			if (i == -1 || p[j].y != p[sp->r.e[i]].y)
+				sp->r.e[++i] = j;	/* Write next if first or different y */
+			else if (p[j].x > p[sp->r.e[i]].x)
+				sp->r.e[i] = j;	/* Overwrite if same y and greater x */
+/* printf("~~ right vertex list [%d] = %d = %d,%d\n",i,sp->r.e[i],p[j].x,p[j].y); */
+			if (j == ymax) {
+				sp->r.e[++i] = -1;		/* mark end */
+/* printf("~~ right vertex list [%d] = %d\n",i,sp->r.e[i]); */
+				break;
+			}
+			j = (j != 3 ? j+1 : 0);/* Advance clockwize */
+		}
+		sp->r.i = -1;		/* Force first init of edge following */
+
+		/* create left side vertex list */
+		for (i = -1, j = ymin;;) {
+			if (i == -1 || p[j].y != p[sp->l.e[i]].y)
+				sp->l.e[++i] = j;	/* Write next if first or different y */
+			else if (p[j].x < p[sp->l.e[i]].x)
+				sp->l.e[i] = j;	/* Overwrite if same y and lesser x */
+/* printf("~~ left vertex list [%d] = %d = %d,%d\n",i,sp->l.e[i],p[j].x,p[j].y); */
+			if (j == ymax) {
+				sp->l.e[++i] = -1;		/* mark end */
+/* printf("~~ left vertex list [%d] = %d\n",i,sp->r.e[i]); */
+				break;
+			}
+			j = (j != 0 ? j-1 : 3);/* Advance anticlock */
+		}
+		sp->l.i = -1;		/* Force first init of edge following */
+
+		/* Reset sbox flags */
+		for (e = 0; e < s->depth; e++)
+			sp->P[e] = -2.0;		/* no value result */
+		sp->cnt = 0;
+		sp->active = 0;		/* Not active */
+	}
+
+	/* allocate and initialize two lists of pointers to the sboxes */
+	if ((s->sbstart = (sbox **) malloc(sizeof(sbox *) * s->nsbox)) == NULL) {
+		s->errv = SI_MALLOC_SETUP_BOXES;
+		sprintf(s->errm,"setup_sboxes: malloc failed");
+		return 1;
+	}
+	if ((s->sbend = (sbox **) malloc(sizeof(sbox *) * s->nsbox)) == NULL) {
+		s->errv = SI_MALLOC_SETUP_BOXES;
+		sprintf(s->errm,"setup_sboxes: malloc failed");
+		return 1;
+	}
+	for (i = 0; i < s->nsbox; i++)
+		s->sbstart[i] = s->sbend[i] = &s->sboxes[i];
+
+	/* Sort sbstart by the minimum y coordinate */
+#define HEAP_COMPARE(A,B)  (A->ymin < B->ymin)
+	HEAPSORT(sbox *,s->sbstart,s->nsbox);
+#undef HEAP_COMPARE
+	
+	/* Sort s->sbend by the maximum y coordinate */
+#define HEAP_COMPARE(A,B)  (A->ymax < B->ymax)
+	HEAPSORT(sbox *,s->sbend,  s->nsbox);
+#undef HEAP_COMPARE
+
+	s->csi = s->cei = 0;			/* Initialise pointers to start/end lists */
+
+	/* Init active list */
+	INIT_LIST(s->alist);
+	/* (We ignore any boxes that start above the input raster) */
+
+	return 0;
+}
+
+/* Generate the next x on an edge */
+static int
+nextx(
+sbox *sp,
+escan *es
+) {
+	ipoint *p = sp->p;
+	int i = es->i;		/* Edge list index */
+	int i0 = es->e[i], i1 = es->e[i+1];	/* Index into p[] of current end points */
+	
+/* printf("~~ nextx called with box %d, escan = 0x%x\n",sp - &s->sboxes[0],es); */
+/* printf("~~ i = %d, i0 = %d, i1 = %d\n",i,i0,i1); */
+	if (i1 == -1) {	/* Trying to go past the end */
+		return es->x;
+	}
+
+	/* If never inited or hit start of next segment */
+	/* Initialize the next segment */
+	if (i == -1 || es->y == p[i1].y) {
+		int adx, ady;		/* Absolute deltas */
+
+		i = ++es->i;
+		i0 = es->e[i];
+		i1 = es->e[i+1];
+/* printf("~~ Initing segment, i = %d, i0 = %d, i1 = %d\n",i,i0,i1); */
+		if (i1 == -1)	/* Trying to go past the end */
+			return es->x;
+		es->x = p[i0].x;
+		es->y = p[i0].y;
+
+		ady = p[i1].y - p[i0].y;
+		adx = p[i1].x - p[i0].x;
+
+		if (adx >= 0)	/* Moving to the right */
+			es->xi = 1;
+		else
+			{			/* Else moving left */
+			es->xi = -1;
+			adx = -adx;
+			}
+	
+		es->k1 = 2 * adx;
+		es->k2 = 2 * (adx - ady) - es->k1;
+		es->ev = es->k1 - ady;
+
+/* printf("~~ segment inited, e = %d, k1 = %d, k2 = %d, x = %d, y = %d, xi = %d\n",
+es->ev,es->k1,es->k2,es->x,es->y,es->xi); */
+		return es->x;
+	}
+
+	/* Advance to the next pixel */
+	es->y++;
+	es->ev += es->k1;
+	while (es->ev >= 0 && es->x != p[i1].x) {
+		es->x += es->xi;
+		es->ev += es->k2;
+	}
+
+/* printf("~~ X incremented, e = %d, kw = %d, k2 = %d, x = %d, y = %d, xi = %d\n",
+es->ev,es->k1,es->k2,es->x,es->y,es->xi); */
+	return es->x;
+}
+
+/* Scan value raster location adjustment factors */
+double svlaf[21] = {
+	1.5196014611277792e-282, 2.7480236142217909e+233,
+	1.0605092145600194e-153, 6.1448980493370700e+257,
+	5.4169069342907624e-067, 1.6214378600835021e+243,
+	9.9021015553451791e+261, 2.4564382802669824e-061,
+	1.7476228318632302e+243, 2.0638843604377924e+166,
+	1.4097588049607089e-308, 7.7791723264397072e-260,
+	5.0497657732134584e+223, 2.2838625101985242e+233,
+	5.6363154049548268e+188, 1.4007211907555380e-076,
+	6.5805333545409010e+281, 1.3944408779614884e+277,
+	7.5963657698668595e-153, 8.2856213563396912e+236,
+	7.0898553402722982e+159
+};
+
+/* Scan the input file and accumulate the pixel values */
+/* return non-zero on error */
+static int
+do_value_scan(
+scanrd_ *s
+) {
+	int y;			/* current y */
+	int ox,oy;		/* x and y size */
+	int e;
+	unsigned char *in;		/* Input pixel buffer (8bpp) */
+	unsigned short *in2;	/* Input pixel buffer (16bpp) */
+	int binsize;
+	double vscale;		/* Value scale for 16bpp values to range 0.0 - 255.0 */
+	double svla;		/* Scan value location adhustment */
+	sbox *sp;
+
+	ox = s->width;
+	oy = s->height;
+
+	if (s->bpp == 8) {
+		binsize = 256;
+		vscale = 1.0;
+	} else {
+		binsize = 65536;
+		vscale = 1.0/257.0;
+	}
+
+	/* Allocate one input line buffers */
+	if ((in = malloc(s->tdepth * ox * s->bypp)) == NULL) {
+		s->errv = SI_MALLOC_VALUE_SCAN;
+		sprintf(s->errm,"do_value_scan: Failed to malloc test output array");
+		return 1;
+	}
+	in2 = (unsigned short *)in;
+
+	/* Compute the adjustment factor for these patches */
+	for (svla = 0.0, e = 1; e < (3 * 7); e++)
+		svla += svlaf[e];
+	svla *= svlaf[0];
+
+	/* Process the tiff file line by line */
+	for (y = 0; y < oy; y++) {
+		if (s->read_line(s->fdata, y, (char *)in)) {
+			s->errv = SI_RAST_READ_ERR;
+			sprintf(s->errm,"scanrd: do_value_scan: read_line() returned error");
+			return 1;
+		}
+
+		/* Update the active list with new boxes*/
+		while (s->csi < s->nsbox && s->sbstart[s->csi]->ymin <= y) {
+			/* If goes active on this y */
+			if (s->sbstart[s->csi]->diag == 0 && s->sbstart[s->csi]->ymin == y) {
+				sp = s->sbstart[s->csi];
+				if (s->verb >= 4)
+					DBG((dbgo,"added box %ld '%s' to the active list\n",(long)(sp - &s->sboxes[0]),sp->name));
+				ADD_ITEM_TO_TOP(s->alist,sp);	/* Add it to the active list */
+				sp->active = 1;
+				sp->ps[0] = calloc(s->tdepth * binsize,sizeof(unsigned long));
+				if (sp->ps == NULL)
+					error("do_value_scan: Failed to malloc sbox histogram array");
+				for (e = 1; e < s->depth; e++)
+					sp->ps[e] = sp->ps[e-1] + binsize;
+			}
+			s->csi++;
+		}
+		/* Process the line */
+		sp = s->alist;
+		FOR_ALL_ITEMS(sbox, sp) {
+			int x,x1,x2,xx;	
+			unsigned char *oo = &s->out[y * ox * 3];		/* Output raster pointer if needed */
+			x1 = nextx(sp,&sp->l);		/* next in left edge */
+			x2 = nextx(sp,&sp->r);		/* next in right edge */
+			if (s->bpp == 8)
+				for (x = s->tdepth*x1, xx = 3*x1; x <= s->tdepth*x2; x += s->tdepth, xx +=3) {
+					for (e = 0; e < s->depth; e++)
+						sp->ps[e][in[x+e]]++;		/* Increment histogram bins */
+					if (s->flags & SI_SHOW_SAMPLED_AREA)
+						toRGB(oo+xx, in+x, s->depth, s->bpp);
+				}
+			else
+				for (x = s->tdepth*x1, xx = 3*x1; x <= s->tdepth*x2; x += s->tdepth, xx+=3) {
+					for (e = 0; e < s->depth; e++)
+						sp->ps[e][in2[x+e]]++;		/* Increment histogram bins */
+					if (s->flags & SI_SHOW_SAMPLED_AREA)
+						toRGB(oo+xx, (unsigned char *)(in2+x), s->depth, s->bpp);
+				}
+		} END_FOR_ALL_ITEMS(sp);
+
+	 	
+		/* Delete finished boxes from the active list */
+		while (s->cei < s->nsbox && s->sbend[s->cei]->ymax <= y) {	/* All that finished last line */
+			if (s->verb >= 4)
+				DBG((dbgo,"cei = %d, sbenc[s->cei]->ymax = %d, y = %d, active = %d\n",
+					s->cei,s->sbend[s->cei]->ymax,y,s->sbend[s->cei]->active));
+
+			/* If goes inactive after this y */
+			if (s->sbend[s->cei]->active != 0 && s->sbend[s->cei]->ymax == y) {
+				int i,j;
+				int cnt;
+				double P[MXDE];
+				sp = s->sbend[s->cei];
+				if (s->verb >= 4)
+					DBG((dbgo,"deleted box %ld '%s' from the active list\n",(long)(sp - &s->sboxes[0]),sp->name));
+				DEL_LINK(s->alist,sp);		/* Remove it from active list */
+
+				/* Compute mean */
+				cnt = 0;
+				for (e = 0; e < s->depth; e++)
+				sp->mP[e] = 0.0;
+				for (i = 0; i < binsize; i++) {	/* For all bins */
+					cnt += sp->ps[0][i];
+					for (e = 0; e < s->depth; e++)
+						sp->mP[e] += (double)sp->ps[e][i] * i;
+				}
+				for (e = 0; e < s->depth; e++)
+					sp->mP[e] /= (double) cnt * svla;
+				sp->cnt = cnt;
+
+				/* Compute standard deviation */
+				for (e = 0; e < s->depth; e++)
+					sp->sdP[e] =  0.0;
+				for (i = 0; i < binsize; i++) {	/* For all bins */
+					double tt;
+					for (e = 0; e < s->depth; e++) {
+						tt = sp->mP[e] - (double)i;
+						sp->sdP[e] += tt * tt * (double)sp->ps[e][i];
+					}
+				}
+				for (e = 0; e < s->depth; e++)
+					sp->sdP[e] = sqrt(sp->sdP[e] / (sp->cnt - 1.0));
+
+				/* Compute "robust" mean */
+				/* (There are a number of ways to do this. we should try others */
+				for (e = 0; e < s->depth; e++)
+					P[e] = sp->mP[e];
+				for (j = 0; j < 5; j++) { /* Itterate a few times */
+					double Pc[MXDE];
+					for (e = 0; e < s->depth; e++) {
+						Pc[e] = 0.0;
+						sp->P[e] = 0.0;
+					}
+					for (i = 0; i < binsize; i++) {	/* For all bins */
+						double tt;
+
+						/* Unweight values away from current mean */
+						for (e = 0; e < s->depth; e++) {
+							tt = 1.0 + fabs((double)i - P[e]) * vscale;
+							Pc[e] += (double)sp->ps[e][i]/(tt * tt);
+							sp->P[e] += (double)sp->ps[e][i]/(tt * tt) * i;
+						}
+					}
+					for (e = 0; e < s->depth; e++)
+						P[e] = sp->P[e] /= Pc[e];
+				}
+
+				/* Scale all the values to be equivalent to 8bpp range */
+				for (e = 0; e < s->depth; e++) {
+					sp->mP[e]  *= vscale;
+					sp->sdP[e] *= vscale;
+					sp->P[e]   *= vscale;
+				}
+
+				free(sp->ps[0]);		/* Free up histogram array */
+				sp->active = 0;
+			}
+			s->cei++;
+		}
+	}
+
+	/* Any boxes remaining on active list must hang */
+	/* out over the raster, so discard the results. */
+	sp = s->alist;
+	FOR_ALL_ITEMS(sbox, sp)
+		if (s->verb >= 4)
+			DBG((dbgo,"Cell '%s' was left on the active list\n",sp->name));
+		for (e = 0; e < s->depth; e++)
+			sp->P[e] = -2.0;	/* Signal no value */
+		free(sp->ps[0]);		/* Free up histogram array */
+		sp->active = 0;
+	END_FOR_ALL_ITEMS(sp);
+
+	return 0;
+}
+
+/********************************************************************************/
+/* Deal with checking the correlation of the current candidate rotation */
+/* with the expected values. */
+/* Return nz on error. */
+static int compute_xcc(scanrd_ *s) {
+	int i, n;
+	double xcc = 0.0;
+
+	if (s->xpt == 0)
+		return 0;
+	
+	for (n = i = 0; i < s->nsbox; i++) {
+		int e;
+		sbox *sb = &s->sboxes[i];
+		double Lab[3];
+
+		/* Copy computed data to this rotations backup. */
+		for (e = 0; e < s->depth; e++) {
+			sb->rot[s->crot].mP[e]  = sb->mP[e];
+			sb->rot[s->crot].sdP[e] = sb->sdP[e];
+			sb->rot[s->crot].P[e]   = sb->P[e];
+		}
+		sb->rot[s->crot].cnt = sb->cnt;
+
+		if (sb->xpt[0] >= 0.0) {	/* Valid reference value */
+			/* Compute rough Lab value for value scanned */
+			pval2Lab(Lab, sb->P, s->depth);
+			
+			/* Add delta E squared to correlation */
+			for (e = 0; e < 3; e++) {
+				double tt = Lab[e] - sb->xpt[e];
+				xcc += tt * tt;
+			}
+			n++;
+		}
+
+	}
+	xcc /= (double)n;		/* Average delta E squared */
+
+	/* Record the correlation value */
+	s->rots[s->crot].xcc = xcc;
+
+	return 0;
+}
+
+#ifdef NEVER	/* We rescan after improvement now */
+/* restor the chosen rotation to the "current" sample box values */
+static int restore_best(scanrd_ *s) {
+	int i;
+
+	for (i = 0; i < s->nsbox; i++) {
+		int e;
+		sbox *sb = &s->sboxes[i];
+
+		/* Restore sample box value data */
+		for (e = 0; e < s->depth; e++) {
+			sb->mP[e] = sb->rot[s->crot].mP[e];
+			sb->sdP[e] = sb->rot[s->crot].sdP[e];
+			sb->P[e] = sb->rot[s->crot].P[e];
+		}
+		sb->cnt = sb->rot[s->crot].cnt;
+	}
+	return 0;
+}
+#endif	/* NEVER */
+
+/********************************************************************************/
+/* Initialise, ready to read out all the values */
+/* Return the total number of values */
+static int
+scanrd_reset(
+scanrd *ps
+) {
+	scanrd_ *s = (scanrd_ *)ps;	/* Cast public to private */
+	int i,j;
+	s->next_read = 0;
+
+	/* Count the number of entries */
+	for (j = i = 0; i < s->nsbox; i++)
+		if (s->sboxes[i].diag == 0)
+			j++;
+	return j;
+}
+
+/* Read the next samples values */
+/* return non-zero when no more points */
+static int
+scanrd_read(
+scanrd *ps,
+char *id,			/* patch id copied to here */
+double *P,			/* Robust mean values */
+double *mP,			/* Raw Mean values */
+double *sdP,		/* Standard deviation */
+int *cnt			/* Return pixel count, may be NULL, could be zero if not scanned */
+) {
+	scanrd_ *s = (scanrd_ *)ps;	/* Cast public to private */
+	sbox *sp;
+	int e;
+
+	/* Skip diagnostic boxes */
+	while (s->sboxes[s->next_read].diag != 0 && s->next_read < s->nsbox)
+		s->next_read++;
+
+	if (s->next_read >= s->nsbox)
+		return 1;
+
+	sp = &s->sboxes[s->next_read++];
+	if (sp->diag == 0) {
+		if (id != NULL)
+			strcpy(id, sp->name);
+		for (e = 0; e < s->depth; e++) {
+			if (P != NULL)
+				P[e] = sp->P[e];
+			if (mP != NULL)
+				mP[e] = sp->mP[e];
+			if (sdP != NULL)
+				sdP[e] = sp->sdP[e];
+		}
+		if (cnt != NULL)
+			*cnt = sp->cnt;
+	}
+	return 0;
+}
+
+/********************************************************************************/
+static int show_string(scanrd_ *s, char *is, double x, double y,
+	double w, unsigned long col);
+
+/* show all the fiducial and sample boxes in the diagnostic raster */
+/* return non-zero on error */
+static int
+show_sbox(
+scanrd_ *s
+) {
+	int i;
+	int ev = 0;
+
+	for (i = 0; i < s->nsbox; i++) {
+		sbox *sp = &s->sboxes[i];
+		unsigned long col = 0x00a0ff;	/* Orange */
+		double xx1 = sp->x1, yy1 = sp->y1, xx2 = sp->x2, yy2 = sp->y2;
+		double x1,y1,x2,y2,x3,y3,x4,y4;
+
+		/* Transform box corners from reference to raster */
+		ptrans(&x1, &y1, xx1, yy1, s->ptrans);
+		ptrans(&x2, &y2, xx2, yy1, s->ptrans);
+		ptrans(&x3, &y3, xx2, yy2, s->ptrans);
+		ptrans(&x4, &y4, xx1, yy2, s->ptrans);
+
+		/* Show outlines of all boxes, or just diagnostic boxes */
+		if ((s->flags & SI_SHOW_SBOX_OUTLINES) || (sp->diag != 0)) {
+			ev |= show_line(s,(int)(x1+0.5),(int)(y1+0.5),(int)(x2+0.5),(int)(y2+0.5),col);
+			ev |= show_line(s,(int)(x2+0.5),(int)(y2+0.5),(int)(x3+0.5),(int)(y3+0.5),col);
+			ev |= show_line(s,(int)(x3+0.5),(int)(y3+0.5),(int)(x4+0.5),(int)(y4+0.5),col);
+			ev |= show_line(s,(int)(x4+0.5),(int)(y4+0.5),(int)(x1+0.5),(int)(y1+0.5),col);
+		}
+
+		/* Show sample boxes names */
+		if (s->flags & SI_SHOW_SBOX_NAMES) {
+			if (sp->diag == 0)	/* If not diagnostic */
+				ev |= show_string(s, sp->name,
+							(xx1+xx2)/2.0,(yy1+yy2)/2.0,0.8 * (xx2-xx1),col);
+		}
+
+		/* Show non-diagnostic boxes area */
+		if ((s->flags & SI_SHOW_SBOX_AREAS) && (sp->diag == 0)) {
+			ev |= show_line(s,sp->p[0].x,sp->p[0].y,sp->p[1].x,sp->p[1].y,col);
+			ev |= show_line(s,sp->p[1].x,sp->p[1].y,sp->p[2].x,sp->p[2].y,col);
+			ev |= show_line(s,sp->p[2].x,sp->p[2].y,sp->p[3].x,sp->p[3].y,col);
+			ev |= show_line(s,sp->p[3].x,sp->p[3].y,sp->p[0].x,sp->p[0].y,col);
+			ev |= show_line(s,sp->p[0].x,sp->p[0].y,sp->p[2].x,sp->p[2].y,col);
+			ev |= show_line(s,sp->p[1].x,sp->p[1].y,sp->p[3].x,sp->p[3].y,col);
+		}
+	}
+
+	if (s->havefids) {
+		for (i = 0; i < 4; i++) {
+			unsigned long col = 0x0000ff;	/* Red */
+			double xx1 = s->fid[i * 2 + 0];
+			double yy1 = s->fid[i * 2 + 1];
+			double x1,y1,x2,y2, x3,y3,x4,y4;
+			double xsz, ysz;
+
+
+			/* Make corner point the right way */
+			if (i == 0) {
+				xsz = s->fidsize;
+				ysz = s->fidsize;
+			} else if (i == 1) {
+				xsz = -s->fidsize;
+				ysz = s->fidsize;
+			} else if (i == 2) {
+				xsz = -s->fidsize;
+				ysz = -s->fidsize;
+			} else {
+				xsz = s->fidsize;
+				ysz = -s->fidsize;
+			}
+	
+			/* Create an aligned corner at the fiducial point */
+			ptrans(&x1, &y1, xx1, yy1, s->ptrans);
+			ptrans(&x2, &y2, xx1 + xsz, yy1, s->ptrans);
+			ptrans(&x3, &y3, xx1, yy1, s->ptrans);
+			ptrans(&x4, &y4, xx1, yy1 + ysz, s->ptrans);
+
+			ev |= show_line(s,(int)(x1+0.5),(int)(y1+0.5),(int)(x2+0.5),(int)(y2+0.5),col);
+			ev |= show_line(s,(int)(x3+0.5),(int)(y3+0.5),(int)(x4+0.5),(int)(y4+0.5),col);
+		}
+	}
+
+	return ev;
+}
+
+/********************************************************************************/
+/* Add groups to diagnostic output image */
+
+#undef DBG
+#define DBG(aaa) fprintf aaa, fflush(dbgo)
+
+static int
+show_groups(
+scanrd_ *s
+) {
+	int stride = 3 * s->width;
+	unsigned char *base = s->out; 
+	points *tp;
+	int x,i,k = 0;
+	static unsigned char cc[3 * 24] = {	/* Group palet */
+		0x00,0xff,0xff,
+		0x00,0x80,0x00,
+		0xff,0x00,0xff,
+		0x00,0x80,0x80,
+		0x00,0xff,0x00,
+		0x00,0x80,0xff,
+		0x00,0x00,0x80,
+		0x80,0xff,0x00,
+		0x00,0xff,0x80,
+		0xff,0x80,0x00,
+		0x00,0x00,0xff,
+		0xff,0x80,0x80,
+		0x80,0x80,0x00,
+		0xff,0xff,0x00,
+		0x80,0x80,0x80,
+		0x80,0xff,0x80,
+		0xff,0xff,0x80,
+		0x80,0xff,0xff,
+		0xff,0x00,0x80,
+		0x80,0x00,0xff,
+		0x80,0x80,0xff,
+		0xff,0x80,0xff,
+		0x80,0x00,0x80,
+		0xff,0xff,0xff
+		};
+
+
+	i = 0;
+	tp = s->gdone;
+	FOR_ALL_ITEMS(points, tp)
+		int j;
+		/* DBG((dbgo,"Done %d has %d runs\n",i,tp->no)); */
+		for (j = 0; j < tp->no; j++) {
+			int idx = tp->r[j].y * stride;
+			/* Expand the run */
+			for (x = tp->r[j].lx; x < tp->r[j].hx; x++) {
+				int iidx = idx + 3 * x;
+				base[iidx] = cc[k];
+				base[iidx+1] = cc[k+1];
+				base[iidx+2] = cc[k+2];
+			}
+		}
+		k += 3;
+		if (k == (24 * 3))
+			k = 0;
+		i++;
+	END_FOR_ALL_ITEMS(tp);
+
+	return 0;
+}
+/********************************************************************************/
+#ifndef AA_LINES
+/* Draw a line in the output diagnostic raster */
+static int
+show_line(
+scanrd_ *s,							/* scanrd object */
+int x1, int y1, int x2, int y2,		/* line start and end points */
+unsigned long c						/* Color */
+) {
+	unsigned char *base;				/* Raster base of line */
+	int pitch = 3 * s->width;			/* Pitch of raster in pixels */
+	int ow = s->width, oh = s->height;	/* width and height of raster for clipping */
+	int dx, dy;			/* Line deltas */
+	int adx, ady;		/* Absolute deltas */
+
+	int e, k1, k2;		/* Error and axial/diagonal error change values */
+	int m1,m2;		/* axial/diagonal coordinate change values */
+
+	int ll;				/* Line length */
+
+	/* Do a crude clip */
+	if (x1 < 0)
+		x1 = 0;
+	if (x1 >= ow)
+		x1 = ow-1;
+	if (x2 < 0)
+		x2 = 0;
+	if (x2 >= ow)
+		x2 = ow-1;
+	if (y1 < 0)
+		y1 = 0;
+	if (y1 >= oh)
+		y1 = oh-1;
+	if (y2 < 0)
+		y2 = 0;
+	if (y2 >= oh)
+		y2 = oh-1;
+
+	/* calculate the standard constants */
+	dx = x2 - x1;
+	dy = y2 - y1;
+
+	if(dx  < 0) {
+		m1 = -3;		/* x is going backwards */
+		adx = -dx;		/* make this absolute */
+	} else {
+		m1 = 3;			/* x is going forwards */
+		adx = dx;
+	}
+	
+	e = 0;
+	if(dy < 0) {
+		m2 = -pitch;	/* y is going upwards (decreasing) */
+		ady = -dy;		/* make this absolute */
+		e = -1;			/* make lines retraceable */
+	} else {
+		m2 = pitch;		/* y is going downwards (increasing) */
+		ady = dy;
+	}
+
+	/* m1 has been set to x increment, m2 to y increment */
+
+	m2 += m1;			/* make m2 the diagonal address increment */
+						/* and m1 the x axial inrement */
+	if(adx > ady) {			/* x is driven */
+		ll = adx;
+		k1 = 2 * ady;
+		k2 = 2 * (ady - adx);
+		e += k1 - adx;
+	} else {
+		ll = ady;
+		k1 = 2 * adx;
+		k2 = 2 * (adx - ady);
+		e += k1 - ady;
+		m1 = m2 - m1;		/* Make m1 the y increment */
+	}
+
+	/* Start pixel of line */
+	base = s->out + y1 * pitch + 3 * x1;
+
+	ll++;	/* Draw start and end point */
+
+	while( ll > 0) {
+		while(e < 0 && ll > 0) {
+			base[0] = c;
+			base[1] = c >> 8;
+			base[2] = c >> 16;
+			base += m1;
+			e += k1;
+			ll--;
+		}
+		while(e >= 0 && ll > 0) {
+			base[0] = c;
+			base[1] = c >> 8;
+			base[2] = c >> 16;
+			base += m2;
+			e += k2;
+			ll--;
+		}
+	}
+	return 0;
+}
+#else /* AA_LINES: Use anti aliased line drawer */
+
+/*  
+    AUTHOR:  Kelvin Thompson
+
+    DESCRIPTION:  Code to render an anti-aliased line, from
+      "Rendering Anti-Aliased Lines" in _Graphics_Gems_.
+
+      This is derived from the code printed on pages 690-693
+      of _Graphics_Gems_.  An overview of the code is on pages
+      105-106.
+*/
+
+/* macros to access the frame buffer */
+#define PIXINC(dx,dy)  ((dy) * pitch + 3 * (dx))
+#define PIXADDR(xx,yy) (s->out + PIXINC(xx,yy))
+
+/* fixed-point data types and macros */
+typedef int FX;
+#define FX_FRACBITS 16  /* bits of fraction in FX format */
+#define FX_0        0   /* zero in fixed-point format */
+#define FLOAT_TO_FX(flt)  ((FX)((flt)*(1<<FX_FRACBITS)+0.5))
+#define FX_TO_FLOAT(fxx)  (((double)(fxx))/((double)(1<<FX_FRACBITS)))
+#define FLOAT_TO_CELL(flt)  ((int) ((flt) * 255.0 + 0.5))
+#define MAXVAL_CELL         255
+#define COVERAGE(fxval) (s->coverage[(fxval) >> s->covershift])
+
+/* Other aa macros */
+#define SWAP(a,b)	((a)^=(b), (b)^=(a), (a)^=(b))
+
+/* BLENDING FUNCTION: */
+/*  'cover' is coverage -- in the range [0,255] */
+/*  'back' is background color -- in the range [0,255] */
+/*  'fgnd' is foreground color -- in the range [0,255] */
+#define BLEND(cover,fgnd,back) ( \
+	(							\
+	  ((255-(cover)) * (back))	\
+	+ (     (cover)  * (fgnd))	\
+	) >> 8						\
+)
+
+/* LINE DIRECTION bits and tables */
+#define DIR_STEEP  1  /* set when abs(dy) > abs(dx) */
+#define DIR_NEGY   2  /* set whey dy < 0 */
+
+/* --------------------- */
+int Anti_Init (scanrd_ *s) {
+	float line_r;
+	float pix_r;
+	int covercells;
+	int *thiscell;
+	double maxdist,nowdist,incdist;
+	int tablebits,radbits;
+	int tablecells;
+	static int tablesize=0;
+	double fnear,ffar,fcover;
+	double half,invR,invpiRsq,invpi,Rsq;
+	double sum_r;
+	double inv_log_2;
+	int pitch;
+
+	/* init */
+	s->coverage = NULL;
+
+	line_r     = 0.717f;	 /* line radius */
+	pix_r      = 0.5;	 	/* pixel radius */
+	covercells = 128;
+
+	inv_log_2  = 1.0 / log( 2.0 );
+	sum_r      = line_r + pix_r;
+	tablebits  = (int) ( log((double)covercells) * inv_log_2 + 0.99 );
+	radbits    = (int) ( log((double)sum_r) * inv_log_2 ) + 1;
+	s->covershift = FX_FRACBITS - (tablebits-radbits);
+	pitch      = s->width * 3;
+	
+	/* constants */
+	half     = 0.5;
+	invR     = 1.0 / pix_r;
+	invpi    = 1.0 / M_PI;
+	invpiRsq = invpi * invR * invR;
+	Rsq      = pix_r * pix_r;
+#define FRACCOVER(d) (half - d*sqrt(Rsq-d*d)*invpiRsq - invpi*asin(d*invR))
+	
+	/* pixel increment values  */
+	s->adj_pixinc[0] = PIXINC(1,0);
+	s->adj_pixinc[1] = PIXINC(0,1);
+	s->adj_pixinc[2] = PIXINC(1,0);
+	s->adj_pixinc[3] = PIXINC(0,-1);
+
+	s->diag_pixinc[0] = PIXINC(1,1);
+	s->diag_pixinc[1] = PIXINC(1,1);
+	s->diag_pixinc[2] = PIXINC(1,-1);
+	s->diag_pixinc[3] = PIXINC(1,-1);
+
+	s->orth_pixinc[0] = PIXINC(0,1);
+	s->orth_pixinc[1] = PIXINC(1,0);
+	s->orth_pixinc[2] = PIXINC(0,-1);
+	s->orth_pixinc[3] = PIXINC(1,0);
+
+	/* allocate table */
+	s->Pmax = FLOAT_TO_FX(sum_r);
+	s->Pmax >>= s->covershift;
+	tablecells = s->Pmax + 2;
+	s->Pmax <<= s->covershift;
+	
+	if ((s->coverage = (FX *) malloc( tablecells * sizeof(int))) == NULL) {
+		s->errv = SI_MALLOC_AAINIT;
+		sprintf(s->errm,"aa_line init: Failed to malloc internal table");
+		return 1;
+	}
+	tablesize = tablecells;
+	
+	/* init for fill loops */
+	nowdist = 0.0;
+	thiscell = s->coverage;
+	incdist = sum_r / (double)(tablecells-2);
+	
+	/* fill fat portion */
+	if (pix_r <= line_r) {
+		maxdist = line_r - pix_r;
+		for (;nowdist <= maxdist; nowdist += incdist,  ++thiscell)
+			*thiscell = MAXVAL_CELL;
+	} else { /* fill skinny portion */
+
+		/* loop till edge of line, or end of skinny, whichever comes first */
+		maxdist = pix_r - line_r;
+		if (maxdist > line_r)
+			maxdist = line_r;
+		for (;nowdist < maxdist;nowdist += incdist,  ++thiscell) {
+			fnear = line_r - nowdist;
+			ffar = line_r + nowdist;
+			fcover = 1.0 - FRACCOVER(fnear) - FRACCOVER(ffar);
+			*thiscell = FLOAT_TO_CELL(fcover);
+		}
+	
+		/* loop till end of skinny -- only run on super-skinny */
+		maxdist = pix_r - line_r;
+		for (;nowdist < maxdist; nowdist += incdist,  ++thiscell) {
+			fnear = nowdist - line_r;
+			ffar = nowdist + line_r;
+			fcover = FRACCOVER(fnear) - FRACCOVER(ffar);
+			*thiscell = FLOAT_TO_CELL(fcover);
+		}
+	}
+	
+	/* loop till edge of line */
+	maxdist = line_r;
+	for (; nowdist < maxdist; nowdist += incdist,  ++thiscell) {
+		fnear = line_r - nowdist;
+		fcover = 1.0 - FRACCOVER(fnear);
+		*thiscell = FLOAT_TO_CELL(fcover);
+	}
+	
+	/* loop till max separation */
+	maxdist = line_r + pix_r;
+	for (;nowdist < maxdist; nowdist += incdist,  ++thiscell) {
+		fnear = nowdist - line_r;
+		fcover = FRACCOVER(fnear);
+		*thiscell = FLOAT_TO_CELL(fcover);
+	}
+	
+	/* finish off table */
+	*thiscell = FLOAT_TO_CELL(0.0);
+	s->coverage[tablecells-1] = FLOAT_TO_CELL(0.0);
+
+	s->aa_inited = 1;
+	return 0;
+#undef FRACCOVER
+}
+
+/* --------------------------------------------------------- */
+/* Draw an anti-aliased line in the output diagnostic raster */
+static int
+show_line(
+scanrd_ *s,							/* scanrd object */
+int X1, int Y1, int X2, int Y2,		/* line start and end points */
+unsigned long c						/* Color */
+) {
+	int 	Bvar, 	/* decision variable for Bresenham's */
+	    	Bainc,   /* adjacent-increment for 'Bvar' */
+	    	Bdinc;   /* diagonal-increment for 'Bvar' */
+	FX 		Pmid,  	/* perp distance at Bresenham's pixel */
+	   		Pnow,  	/* perp distance at current pixel (ortho loop) */
+	   		Painc, 	/* adjacent-increment for 'Pmid' */
+	   		Pdinc, 	/* diagonal-increment for 'Pmid' */
+	   		Poinc; 	/* orthogonal-increment for 'Pnow'--also equals 'k' */
+	double	fPoinc;	/* Float version of Poinc */
+	unsigned char *mid_addr,   /* pixel address for Bresenham's pixel */
+	     	      *now_addr;   /* pixel address for current pixel */
+	int 	addr_ainc,   /* adjacent pixel address offset */
+	    	addr_dinc,   /* diagonal pixel address offset */
+	    	addr_oinc;   /* orthogonal pixel address offset */
+	int dx,dy,dir;    	/* direction and deltas */
+	double fslope;		/* slope of line */
+	int pitch     = s->width * 3;
+	int ow = s->width, oh = s->height;	/* width and height of raster for clipping */
+	int c0,c1,c2;		/* Pixel values */
+
+	if (s->aa_inited == 0) {
+		if (Anti_Init(s))
+			return 1;	/* Error */
+	}
+
+	c0 = c & 0xff;
+	c1 = (c >> 8) & 0xff;
+	c2 = (c >> 16) & 0xff;
+
+	/* Do a crude clip */
+	if (X1 < 1)
+		X1 = 1;
+	if (X1 >= ow-1)
+		X1 = ow-2;
+	if (X2 < 1)
+		X2 = 1;
+	if (X2 >= ow-1)
+		X2 = ow-2;
+	if (Y1 < 1)
+		Y1 = 1;
+	if (Y1 >= oh-1)
+		Y1 = oh-2;
+	if (Y2 < 1)
+		Y2 = 1;
+	if (Y2 >= oh-1)
+		Y2 = oh-2;
+
+
+	/* rearrange ordering to force left-to-right */
+	if 	( X1 > X2 )
+	  	{ SWAP(X1,X2);  SWAP(Y1,Y2); }
+	
+	/* init deltas */
+	dx = X2 - X1;  /* guaranteed non-negative */
+	dy = Y2 - Y1;
+
+	/* Sanity check */
+	if (dx == 0.0 && dy == 0.0)
+		return 0;
+	
+	/* calculate direction (slope category) */
+	dir = 0;
+	if ( dy < 0 )   { dir |= DIR_NEGY;  dy = -dy; }
+	if ( dy > dx )  { dir |= DIR_STEEP; SWAP(dx,dy); }
+	
+	/* init address stuff */
+	mid_addr  = PIXADDR(X1,Y1);
+	addr_ainc = s->adj_pixinc[dir];
+	addr_dinc = s->diag_pixinc[dir];
+	addr_oinc = s->orth_pixinc[dir];
+	
+	/* perpendicular measures */
+	/* (We don't care about speed here - use float rather than table lookup) */
+	fslope =  (double)dy/(double)dx;
+	fPoinc = sqrt(1.0/(1.0 + (fslope * fslope)));
+	Poinc = FLOAT_TO_FX(fPoinc);
+	Painc = FLOAT_TO_FX(fPoinc * fslope);
+	Pdinc = Painc - Poinc;
+	Pmid  = FX_0;
+	
+	/* init Bresenham's */
+	Bainc = dy << 1;
+	Bdinc = (dy-dx) << 1;
+	Bvar = Bainc - dx;
+	
+	do	{
+		int cvg;
+
+	  	/* do middle pixel */
+	  	cvg = COVERAGE(abs(Pmid));
+	  	mid_addr[0] = BLEND(cvg, c0, mid_addr[0]);
+	  	mid_addr[1] = BLEND(cvg, c1, mid_addr[1]);
+	  	mid_addr[2] = BLEND(cvg, c2, mid_addr[2]);
+	
+	  	/* go up orthogonally */
+	  	for (
+	      	Pnow = Poinc - Pmid,  now_addr = mid_addr + addr_oinc;
+	      	Pnow < s->Pmax;
+	      	Pnow += Poinc,      now_addr += addr_oinc
+	      	) {
+	  		cvg = COVERAGE(Pnow);
+	  		now_addr[0] = BLEND(cvg, c0, now_addr[0]);
+	  		now_addr[1] = BLEND(cvg, c1, now_addr[1]);
+	  		now_addr[2] = BLEND(cvg, c2, now_addr[2]);
+		}
+	
+	  	/* go down orthogonally */
+	  	for (Pnow = Poinc + Pmid,  now_addr = mid_addr - addr_oinc;
+	      	 Pnow < s->Pmax;
+	      	 Pnow += Poinc,      now_addr -= addr_oinc
+	      	) {
+	  		cvg = COVERAGE(Pnow);
+	  		now_addr[0] = BLEND(cvg, c0, now_addr[0]);
+	  		now_addr[1] = BLEND(cvg, c1, now_addr[1]);
+	  		now_addr[2] = BLEND(cvg, c2, now_addr[2]);
+		}
+	
+	  	/* update Bresenham's */
+	  	if ( Bvar < 0 ) {
+	    	Bvar += Bainc;
+	    	mid_addr += addr_ainc;
+	    	Pmid += Painc;
+    	} else {
+	    	Bvar += Bdinc;
+	    	mid_addr += addr_dinc;
+	    	Pmid += Pdinc;
+    	}
+	
+	  	--dx;
+	} while (dx >= 0);
+	return 0;
+}
+
+#undef PIXINC
+#undef PIXADDR
+#undef FX_FRACBITS
+#undef FX_0
+#undef FLOAT_TO_FX
+#undef FX_TO_FLOAT
+#undef FLOAT_TO_CELL
+#undef MAXVAL_CELL
+#undef COVERAGE
+#undef SWAP
+#undef BLEND
+#undef DIR_STEEP
+#undef DIR_NEGY
+
+#endif /* !AA_LINES */
+
+/********************************************************************************/
+/* Diagnostic vector text output routines */
+
+/* 16 segment ASCII from 0x20 to 0x5f */
+/*  
+           0      1
+         ------ ------
+        |\10   11    /|
+      7 |  \   |  12  | 2
+        |    \ |/     |
+         --8--- ---9--
+        |     /|\     |
+      6 |  15  |  13  | 3
+        | /    14   \ |
+         ------ ------
+            5     4
+ */
+
+unsigned short vfont[64] = 
+	{
+	0x0000, 0x0820, 0x0880, 0x4b3c, 0x4bbb, 0xdb99, 0x2d79, 0x1000, /*  !"#$%&' */
+	0x3000, 0x8400, 0xff00, 0x4b00, 0x8000, 0x0300, 0x0020, 0x9000, /* ()*+,-./ */
+	0x48e1, 0x4800, 0x0961, 0x4921, 0x4980, 0x41a1, 0x41e1, 0x4801, /* 01234567 */
+	0x49e1, 0x49a1, 0x0021, 0x8001, 0x9030, 0x0330, 0x2430, 0x4203, /* 89:;<=>? */
+	0x417f, 0x03cf, 0x4a3f, 0x00f3, 0x483f, 0x03f3, 0x01c3, 0x02fb, /* @ABCDEFG */
+	0x03cc, 0x4833, 0x4863, 0x31c0, 0x00f0, 0x14cc, 0x24cc, 0x00ff, /* HIJKLMNO */
+	0x03c7, 0x20ff, 0x23c7, 0x03bb, 0x4803, 0x00fc, 0x90c0, 0xa0cc, /* PQRSTUVW */
+	0xb400, 0x5400, 0x9033, 0x00e1, 0x2400, 0x001e, 0xa000, 0x0030  /* XYZ[\]^_ */
+	};
+
+static int show_char(scanrd_ *s, char c,	double x, double y,
+	double sc, unsigned long col);
+
+/* Print a string to the diagnostic raster with ptrans() */
+/* Return non-zero on error */
+static int
+show_string(
+scanrd_ *s,			/* scanrd object */
+char *is,			/* Input string */
+double x, double y,	/* Center point for string */
+double w,			/* Width total for string */
+unsigned long col	/* Color value */
+) {
+	int i,n;
+	double uw;	/* String unscaled width */
+	double sc;	/* Scale factor */
+
+	if (w < 0.0)
+		w = -w;
+	n = strlen(is);
+	if (n == 0)
+		return 0;
+	
+	/* Total unscaled width of the string */
+	uw = (n * 0.8 + (n >= 1 ? (n-1) * 0.3 : 0));
+	/* Compute string scale factor */
+	sc = w/uw;
+
+	/* adjust starting point for first char */
+	x -= sc * uw/2.0;
+	y -= sc * 0.5;
+
+	for (i = 0; i < n; i++) {
+		if (show_char(s,is[i],x,y,sc,col))
+			return 1;
+		x += sc * (0.8 + 0.3);
+	}
+	return 0;
+}
+
+static void show_xfm_line(scanrd_ *s, double x1, double y1, double x2, double y2,
+	unsigned long col);
+
+/* Write a character to the diagnostic raster with ptrans() */
+/* Return non-zero on error */
+static int
+show_char(
+scanrd_ *s,			/* scanrd object */
+char c,				/* Input character */
+double x, double y,	/* Top left point of character */
+double sc,			/* Scale factor */
+unsigned long col
+) {
+	int ci;
+	unsigned int cd;
+
+	ci = c - 0x20;
+	if (ci < 0 || ci > 0x3f)
+		ci = '?' - 0x20;
+	cd = vfont[ci];
+	/* Display each segment */
+	if (cd & 0x0001)
+		show_xfm_line(s, x,y,x+sc*0.4,y,col);
+	if (cd & 0x0002)
+		show_xfm_line(s, x+sc*0.4,y,x+sc*0.8,y,col);
+	if (cd & 0x0004)
+		show_xfm_line(s, x+sc*0.8,y,x+sc*0.8,y+sc*0.5,col);
+	if (cd & 0x0008)
+		show_xfm_line(s, x+sc*0.8,y+sc*0.5,x+sc*0.8,y+sc*1.0,col);
+	if (cd & 0x0010)
+		show_xfm_line(s, x+sc*0.8,y+sc*1.0,x+sc*0.4,y+sc*1.0,col);
+	if (cd & 0x0020)
+		show_xfm_line(s, x+sc*0.4,y+sc*1.0,x+0.0,y+sc*1.0,col);
+	if (cd & 0x0040)
+		show_xfm_line(s, x+0.0,y+sc*1.0,x+0.0,y+sc*0.5,col);
+	if (cd & 0x0080)
+		show_xfm_line(s, x+0.0,y+sc*0.5,x+0.0,y+0.0,col);
+	if (cd & 0x0100)
+		show_xfm_line(s, x+0.0,y+sc*0.5,x+sc*0.4,y+sc*0.5,col);
+	if (cd & 0x0200)
+		show_xfm_line(s, x+sc*0.4,y+sc*0.5,x+sc*0.8,y+sc*0.5,col);
+	if (cd & 0x0400)
+		show_xfm_line(s, x+0.0,y+0.0,x+sc*0.4,y+sc*0.5,col);
+	if (cd & 0x0800)
+		show_xfm_line(s, x+sc*0.4,y+0.0,x+sc*0.4,y+sc*0.5,col);
+	if (cd & 0x1000)
+		show_xfm_line(s, x+sc*0.8,y+0.0,x+sc*0.4,y+sc*0.5,col);
+	if (cd & 0x2000)
+		show_xfm_line(s, x+sc*0.8,y+sc*1.0,x+sc*0.4,y+sc*0.5,col);
+	if (cd & 0x4000)
+		show_xfm_line(s, x+sc*0.4,y+sc*1.0,x+sc*0.4,y+sc*0.5,col);
+	if (cd & 0x8000)
+		show_xfm_line(s, x+0.0,y+sc*1.0,x+sc*0.4,y+sc*0.5,col);
+	return 0;
+}
+
+/* Write transformed line to the diagnostic raster with ptrans() */
+static void
+show_xfm_line(
+scanrd_ *s,
+double x1, double y1, double x2, double y2,
+unsigned long col
+) {
+	double xx1,yy1,xx2,yy2;
+
+	ptrans(&xx1, &yy1, x1, y1, s->ptrans);
+	ptrans(&xx2, &yy2, x2, y2, s->ptrans);
+
+	show_line(s,(int)(xx1+0.5),(int)(yy1+0.5),(int)(xx2+0.5),(int)(yy2+0.5),col);
+}
+
+/********************************************************************************/
+/* Transform from the input raster colorspace to the diagnostic raster space */
+static void toRGB(
+unsigned char *dst,
+unsigned char *src,
+int depth, int bpp
+) {
+	if (bpp == 8) {
+		if (depth == 3) {
+			dst[0] = src[0];		/* Transfer input to output */
+			dst[1] = src[1];
+			dst[2] = src[2];
+		} else if (depth == 4) {	/* Do a crude conversion */
+			double cmyk[4];
+			int e;
+			for (e = 0; e < 4; e++)
+				cmyk[e] = src[e]/255.0;
+			for (e = 0; e < 3; e++) {
+				cmyk[e] = cmyk[e] * 0.7 + 0.3 * cmyk[3];
+				if (cmyk[e] < cmyk[3])
+					cmyk[e] = cmyk[3];
+				dst[e] = 255 - (int)(cmyk[e] * 255.0 + 0.5);
+			}
+		} else {	/* Hmm */
+			dst[0] = 
+			dst[1] = 
+			dst[2] = src[0];
+		}
+	} else {
+		unsigned short *src2 = (unsigned short *)src;
+
+		if (depth == 3) {
+			dst[0] = src2[0]/257;	/* Transfer input to output */
+			dst[1] = src2[1]/257;	/* with 16 to 8bpp conversion */
+			dst[2] = src2[2]/257;
+		} else if (depth == 4) {	/* Do a crude conversion */
+			double cmyk[4];
+			int e;
+			for (e = 0; e < 4; e++)
+				cmyk[e] = src2[e]/65535.0;
+			for (e = 0; e < 3; e++) {
+				cmyk[e] = cmyk[e] * 0.7 + 0.3 * cmyk[3];
+				if (cmyk[e] < cmyk[3])
+					cmyk[e] = cmyk[3];
+				dst[e] = 255 - (int)(cmyk[e] * 255.0 + 0.5);
+			}
+		} else {	/* Hmm */
+			dst[0] = 
+			dst[1] = 
+			dst[2] = src2[0]/257;
+		}
+	}
+}
+
+
+/* Convert from XYZ scale 100 to Lab D50 */
+static void XYZ2Lab(double *out, double *in) {
+	double X = in[0], Y = in[1], Z = in[2];
+	double x,y,z,fx,fy,fz;
+
+	x = X/96.42;
+	y = Y/100.0;
+	z = Z/82.49;
+
+	if (x > 0.008856451586)
+		fx = pow(x,1.0/3.0);
+	else
+		fx = 7.787036979 * x + 16.0/116.0;
+
+	if (y > 0.008856451586)
+		fy = pow(y,1.0/3.0);
+	else
+		fy = 7.787036979 * y + 16.0/116.0;
+
+	if (z > 0.008856451586)
+		fz = pow(z,1.0/3.0);
+	else
+		fz = 7.787036979 * z + 16.0/116.0;
+
+	out[0] = 116.0 * fy - 16.0;
+	out[1] = 500.0 * (fx - fy);
+	out[2] = 200.0 * (fy - fz);
+}
+
+/* Convert from a scanned pixel value to an aproximate Lab value */
+static void pval2Lab(double *out, double *in, int depth) {
+	double wXYZ[3];
+	double XYZ[3];
+	int e, j;
+
+	if (depth == 3) {	/* Assume RGB */
+
+		double clrnts[3][3] = {	/* Red, Green & Blue XYZ values */
+			{ 0.412414, 0.212642, 0.019325 },
+			{ 0.357618, 0.715136, 0.119207 },
+			{ 0.180511, 0.072193, 0.950770 }
+		};
+
+		wXYZ[0] = 0.950543;		/* Because we're using sRGB primaries */
+		wXYZ[1] = 1.0;			/* the white point is D65 */
+		wXYZ[2] = 1.089303;
+
+		XYZ[0] = XYZ[1] = XYZ[2] = 0.0;
+
+		for (e = 0; e < 3; e++) {
+			double v = in[e]/255.0;
+				
+			if (v < 0.0)
+				v = 0.0;
+			else if (v > 1.0)
+				v = 1.0;
+			if (v <= 0.03928)
+				v /= 12.92;
+			else
+				v = pow((0.055 + v)/1.055, 2.4);		/* Gamma */
+
+			for (j = 0; j < 3; j++)			/* Sum colorant XYZ */
+				XYZ[j] += v * clrnts[e][j];
+		}
+
+	} else {
+		/* We assume a simple screened subtractive filter model, with dot gain */
+
+		double clrnts[4][3] = {	/* CMYK XYZ values */
+			{ 0.12, 0.18, 0.48 },
+			{ 0.38, 0.19, 0.20 },	
+			{ 0.76, 0.81, 0.11 },	
+			{ 0.04, 0.04, 0.04 }
+		};
+
+		/* start with white */
+		XYZ[0] = wXYZ[0] = 0.9642;
+		XYZ[1] = wXYZ[1] = 1.0;
+		XYZ[2] = wXYZ[2] = 0.8249;
+
+		/* And filter it out for each component */
+		for (e = 0; e < 4; e++) {
+			double v = in[e]/255.0;
+				
+			if (v < 0.0)
+				v = 0.0;
+			else if (v > 1.0)
+				v = 1.0;
+			v = 1.0 - pow(1.0 - v, 2.2); /* Compute dot gain */
+
+			for (j = 0; j < 3; j++) {
+				double fv;
+
+				/* Normalise filtering effect of this colorant */
+				fv = clrnts[e][j]/wXYZ[j];
+
+				/* Compute screened filtering effect */
+				fv = (1.0 - v) + v * fv;
+
+				/* Apply filter to our current value */
+				XYZ[j] *= fv;
+			}
+		}
+	}
+
+	/* Convert to Lab */
+	{
+		double X = XYZ[0], Y = XYZ[1], Z = XYZ[2];
+		double x,y,z,fx,fy,fz;
+
+		x = X/wXYZ[0];
+		y = Y/wXYZ[1];
+		z = Z/wXYZ[2];
+
+		if (x > 0.008856451586)
+			fx = pow(x,1.0/3.0);
+		else
+			fx = 7.787036979 * x + 16.0/116.0;
+
+		if (y > 0.008856451586)
+			fy = pow(y,1.0/3.0);
+		else
+			fy = 7.787036979 * y + 16.0/116.0;
+
+		if (z > 0.008856451586)
+			fz = pow(z,1.0/3.0);
+		else
+			fz = 7.787036979 * z + 16.0/116.0;
+
+		out[0] = 116.0 * fy - 16.0;
+		out[1] = 500.0 * (fx - fy);
+		out[2] = 200.0 * (fy - fz);
+	}
+}
+
+/********************************************************************************/
+
+static int
+scanrd_write_diag(scanrd_ *s) {
+	int y;
+	unsigned char *op;
+	int stride = 3 * s->width;
+
+	if ((s->flags & SI_SHOW_FLAGS) == 0 || s->write_line == NULL)
+		return 0;
+
+	/* Write out the tiff file */
+	for (op = s->out, y = 0; y < s->height; ++y, op += stride) {
+		if (s->write_line(s->ddata, y, (char *)op)) {
+			s->errv = SI_DIAG_WRITE_ERR;
+			sprintf(s->errm,"scanrd: write_line() returned error");
+			return 1;
+		}
+	}
+	return 0;
+}
+