diff options
Diffstat (limited to 'tiff/tools/tiffmedian.c')
| -rw-r--r-- | tiff/tools/tiffmedian.c | 902 |
1 files changed, 902 insertions, 0 deletions
diff --git a/tiff/tools/tiffmedian.c b/tiff/tools/tiffmedian.c new file mode 100644 index 0000000..be45a2e --- /dev/null +++ b/tiff/tools/tiffmedian.c @@ -0,0 +1,902 @@ +/* $Id: tiffmedian.c,v 1.8.2.1 2010-06-08 18:50:44 bfriesen Exp $ */ + +/* + * Apply median cut on an image. + * + * tiffmedian [-c n] [-f] input output + * -C n - set colortable size. Default is 256. + * -f - use Floyd-Steinberg dithering. + * -c lzw - compress output with LZW + * -c none - use no compression on output + * -c packbits - use packbits compression on output + * -r n - create output with n rows/strip of data + * (by default the compression scheme and rows/strip are taken + * from the input file) + * + * Notes: + * + * [1] Floyd-Steinberg dither: + * I should point out that the actual fractions we used were, assuming + * you are at X, moving left to right: + * + * X 7/16 + * 3/16 5/16 1/16 + * + * Note that the error goes to four neighbors, not three. I think this + * will probably do better (at least for black and white) than the + * 3/8-3/8-1/4 distribution, at the cost of greater processing. I have + * seen the 3/8-3/8-1/4 distribution described as "our" algorithm before, + * but I have no idea who the credit really belongs to. + + * Also, I should add that if you do zig-zag scanning (see my immediately + * previous message), it is sufficient (but not quite as good) to send + * half the error one pixel ahead (e.g. to the right on lines you scan + * left to right), and half one pixel straight down. Again, this is for + * black and white; I've not tried it with color. + * -- + * Lou Steinberg + * + * [2] Color Image Quantization for Frame Buffer Display, Paul Heckbert, + * Siggraph '82 proceedings, pp. 297-307 + */ + +#include "tif_config.h" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#ifdef HAVE_UNISTD_H +# include <unistd.h> +#endif + +#include "tiffio.h" + +#define MAX_CMAP_SIZE 256 + +#define streq(a,b) (strcmp(a,b) == 0) +#define strneq(a,b,n) (strncmp(a,b,n) == 0) + +#define COLOR_DEPTH 8 +#define MAX_COLOR 256 + +#define B_DEPTH 5 /* # bits/pixel to use */ +#define B_LEN (1L<<B_DEPTH) + +#define C_DEPTH 2 +#define C_LEN (1L<<C_DEPTH) /* # cells/color to use */ + +#define COLOR_SHIFT (COLOR_DEPTH-B_DEPTH) + +typedef struct colorbox { + struct colorbox *next, *prev; + int rmin, rmax; + int gmin, gmax; + int bmin, bmax; + uint32 total; +} Colorbox; + +typedef struct { + int num_ents; + int entries[MAX_CMAP_SIZE][2]; +} C_cell; + +uint16 rm[MAX_CMAP_SIZE], gm[MAX_CMAP_SIZE], bm[MAX_CMAP_SIZE]; +int num_colors; +uint32 histogram[B_LEN][B_LEN][B_LEN]; +Colorbox *freeboxes; +Colorbox *usedboxes; +C_cell **ColorCells; +TIFF *in, *out; +uint32 rowsperstrip = (uint32) -1; +uint16 compression = (uint16) -1; +uint16 bitspersample = 1; +uint16 samplesperpixel; +uint32 imagewidth; +uint32 imagelength; +uint16 predictor = 0; + +static void get_histogram(TIFF*, Colorbox*); +static void splitbox(Colorbox*); +static void shrinkbox(Colorbox*); +static void map_colortable(void); +static void quant(TIFF*, TIFF*); +static void quant_fsdither(TIFF*, TIFF*); +static Colorbox* largest_box(void); + +static void usage(void); +static int processCompressOptions(char*); + +#define CopyField(tag, v) \ + if (TIFFGetField(in, tag, &v)) TIFFSetField(out, tag, v) + +int +main(int argc, char* argv[]) +{ + int i, dither = 0; + uint16 shortv, config, photometric; + Colorbox *box_list, *ptr; + float floatv; + uint32 longv; + int c; + extern int optind; + extern char* optarg; + + num_colors = MAX_CMAP_SIZE; + while ((c = getopt(argc, argv, "c:C:r:f")) != -1) + switch (c) { + case 'c': /* compression scheme */ + if (!processCompressOptions(optarg)) + usage(); + break; + case 'C': /* set colormap size */ + num_colors = atoi(optarg); + if (num_colors > MAX_CMAP_SIZE) { + fprintf(stderr, + "-c: colormap too big, max %d\n", + MAX_CMAP_SIZE); + usage(); + } + break; + case 'f': /* dither */ + dither = 1; + break; + case 'r': /* rows/strip */ + rowsperstrip = atoi(optarg); + break; + case '?': + usage(); + /*NOTREACHED*/ + } + if (argc - optind != 2) + usage(); + in = TIFFOpen(argv[optind], "r"); + if (in == NULL) + return (-1); + TIFFGetField(in, TIFFTAG_IMAGEWIDTH, &imagewidth); + TIFFGetField(in, TIFFTAG_IMAGELENGTH, &imagelength); + TIFFGetField(in, TIFFTAG_BITSPERSAMPLE, &bitspersample); + TIFFGetField(in, TIFFTAG_SAMPLESPERPIXEL, &samplesperpixel); + if (bitspersample != 8 && bitspersample != 16) { + fprintf(stderr, "%s: Image must have at least 8-bits/sample\n", + argv[optind]); + return (-3); + } + if (!TIFFGetField(in, TIFFTAG_PHOTOMETRIC, &photometric) || + photometric != PHOTOMETRIC_RGB || samplesperpixel < 3) { + fprintf(stderr, "%s: Image must have RGB data\n", argv[optind]); + return (-4); + } + TIFFGetField(in, TIFFTAG_PLANARCONFIG, &config); + if (config != PLANARCONFIG_CONTIG) { + fprintf(stderr, "%s: Can only handle contiguous data packing\n", + argv[optind]); + return (-5); + } + + /* + * STEP 1: create empty boxes + */ + usedboxes = NULL; + box_list = freeboxes = (Colorbox *)_TIFFmalloc(num_colors*sizeof (Colorbox)); + freeboxes[0].next = &freeboxes[1]; + freeboxes[0].prev = NULL; + for (i = 1; i < num_colors-1; ++i) { + freeboxes[i].next = &freeboxes[i+1]; + freeboxes[i].prev = &freeboxes[i-1]; + } + freeboxes[num_colors-1].next = NULL; + freeboxes[num_colors-1].prev = &freeboxes[num_colors-2]; + + /* + * STEP 2: get histogram, initialize first box + */ + ptr = freeboxes; + freeboxes = ptr->next; + if (freeboxes) + freeboxes->prev = NULL; + ptr->next = usedboxes; + usedboxes = ptr; + if (ptr->next) + ptr->next->prev = ptr; + get_histogram(in, ptr); + + /* + * STEP 3: continually subdivide boxes until no more free + * boxes remain or until all colors assigned. + */ + while (freeboxes != NULL) { + ptr = largest_box(); + if (ptr != NULL) + splitbox(ptr); + else + freeboxes = NULL; + } + + /* + * STEP 4: assign colors to all boxes + */ + for (i = 0, ptr = usedboxes; ptr != NULL; ++i, ptr = ptr->next) { + rm[i] = ((ptr->rmin + ptr->rmax) << COLOR_SHIFT) / 2; + gm[i] = ((ptr->gmin + ptr->gmax) << COLOR_SHIFT) / 2; + bm[i] = ((ptr->bmin + ptr->bmax) << COLOR_SHIFT) / 2; + } + + /* We're done with the boxes now */ + _TIFFfree(box_list); + freeboxes = usedboxes = NULL; + + /* + * STEP 5: scan histogram and map all values to closest color + */ + /* 5a: create cell list as described in Heckbert[2] */ + ColorCells = (C_cell **)_TIFFmalloc(C_LEN*C_LEN*C_LEN*sizeof (C_cell*)); + _TIFFmemset(ColorCells, 0, C_LEN*C_LEN*C_LEN*sizeof (C_cell*)); + /* 5b: create mapping from truncated pixel space to color + table entries */ + map_colortable(); + + /* + * STEP 6: scan image, match input values to table entries + */ + out = TIFFOpen(argv[optind+1], "w"); + if (out == NULL) + return (-2); + + CopyField(TIFFTAG_SUBFILETYPE, longv); + CopyField(TIFFTAG_IMAGEWIDTH, longv); + TIFFSetField(out, TIFFTAG_BITSPERSAMPLE, (short)COLOR_DEPTH); + if (compression != (uint16)-1) { + TIFFSetField(out, TIFFTAG_COMPRESSION, compression); + switch (compression) { + case COMPRESSION_LZW: + case COMPRESSION_DEFLATE: + if (predictor != 0) + TIFFSetField(out, TIFFTAG_PREDICTOR, predictor); + break; + } + } else + CopyField(TIFFTAG_COMPRESSION, compression); + TIFFSetField(out, TIFFTAG_PHOTOMETRIC, (short)PHOTOMETRIC_PALETTE); + CopyField(TIFFTAG_ORIENTATION, shortv); + TIFFSetField(out, TIFFTAG_SAMPLESPERPIXEL, (short)1); + CopyField(TIFFTAG_PLANARCONFIG, shortv); + TIFFSetField(out, TIFFTAG_ROWSPERSTRIP, + TIFFDefaultStripSize(out, rowsperstrip)); + CopyField(TIFFTAG_MINSAMPLEVALUE, shortv); + CopyField(TIFFTAG_MAXSAMPLEVALUE, shortv); + CopyField(TIFFTAG_RESOLUTIONUNIT, shortv); + CopyField(TIFFTAG_XRESOLUTION, floatv); + CopyField(TIFFTAG_YRESOLUTION, floatv); + CopyField(TIFFTAG_XPOSITION, floatv); + CopyField(TIFFTAG_YPOSITION, floatv); + + if (dither) + quant_fsdither(in, out); + else + quant(in, out); + /* + * Scale colormap to TIFF-required 16-bit values. + */ +#define SCALE(x) (((x)*((1L<<16)-1))/255) + for (i = 0; i < MAX_CMAP_SIZE; ++i) { + rm[i] = SCALE(rm[i]); + gm[i] = SCALE(gm[i]); + bm[i] = SCALE(bm[i]); + } + TIFFSetField(out, TIFFTAG_COLORMAP, rm, gm, bm); + (void) TIFFClose(out); + return (0); +} + +static int +processCompressOptions(char* opt) +{ + if (streq(opt, "none")) + compression = COMPRESSION_NONE; + else if (streq(opt, "packbits")) + compression = COMPRESSION_PACKBITS; + else if (strneq(opt, "lzw", 3)) { + char* cp = strchr(opt, ':'); + if (cp) + predictor = atoi(cp+1); + compression = COMPRESSION_LZW; + } else if (strneq(opt, "zip", 3)) { + char* cp = strchr(opt, ':'); + if (cp) + predictor = atoi(cp+1); + compression = COMPRESSION_DEFLATE; + } else + return (0); + return (1); +} + +char* stuff[] = { +"usage: tiffmedian [options] input.tif output.tif", +"where options are:", +" -r # make each strip have no more than # rows", +" -C # create a colormap with # entries", +" -f use Floyd-Steinberg dithering", +" -c lzw[:opts] compress output with Lempel-Ziv & Welch encoding", +" -c zip[:opts] compress output with deflate encoding", +" -c packbits compress output with packbits encoding", +" -c none use no compression algorithm on output", +"", +"LZW and deflate options:", +" # set predictor value", +"For example, -c lzw:2 to get LZW-encoded data with horizontal differencing", +NULL +}; + +static void +usage(void) +{ + char buf[BUFSIZ]; + int i; + + setbuf(stderr, buf); + fprintf(stderr, "%s\n\n", TIFFGetVersion()); + for (i = 0; stuff[i] != NULL; i++) + fprintf(stderr, "%s\n", stuff[i]); + exit(-1); +} + +static void +get_histogram(TIFF* in, Colorbox* box) +{ + register unsigned char *inptr; + register int red, green, blue; + register uint32 j, i; + unsigned char *inputline; + + inputline = (unsigned char *)_TIFFmalloc(TIFFScanlineSize(in)); + if (inputline == NULL) { + fprintf(stderr, "No space for scanline buffer\n"); + exit(-1); + } + box->rmin = box->gmin = box->bmin = 999; + box->rmax = box->gmax = box->bmax = -1; + box->total = imagewidth * imagelength; + + { register uint32 *ptr = &histogram[0][0][0]; + for (i = B_LEN*B_LEN*B_LEN; i-- > 0;) + *ptr++ = 0; + } + for (i = 0; i < imagelength; i++) { + if (TIFFReadScanline(in, inputline, i, 0) <= 0) + break; + inptr = inputline; + for (j = imagewidth; j-- > 0;) { + red = *inptr++ >> COLOR_SHIFT; + green = *inptr++ >> COLOR_SHIFT; + blue = *inptr++ >> COLOR_SHIFT; + if (red < box->rmin) + box->rmin = red; + if (red > box->rmax) + box->rmax = red; + if (green < box->gmin) + box->gmin = green; + if (green > box->gmax) + box->gmax = green; + if (blue < box->bmin) + box->bmin = blue; + if (blue > box->bmax) + box->bmax = blue; + histogram[red][green][blue]++; + } + } + _TIFFfree(inputline); +} + +static Colorbox * +largest_box(void) +{ + register Colorbox *p, *b; + register uint32 size; + + b = NULL; + size = 0; + for (p = usedboxes; p != NULL; p = p->next) + if ((p->rmax > p->rmin || p->gmax > p->gmin || + p->bmax > p->bmin) && p->total > size) + size = (b = p)->total; + return (b); +} + +static void +splitbox(Colorbox* ptr) +{ + uint32 hist2[B_LEN]; + int first=0, last=0; + register Colorbox *new; + register uint32 *iptr, *histp; + register int i, j; + register int ir,ig,ib; + register uint32 sum, sum1, sum2; + enum { RED, GREEN, BLUE } axis; + + /* + * See which axis is the largest, do a histogram along that + * axis. Split at median point. Contract both new boxes to + * fit points and return + */ + i = ptr->rmax - ptr->rmin; + if (i >= ptr->gmax - ptr->gmin && i >= ptr->bmax - ptr->bmin) + axis = RED; + else if (ptr->gmax - ptr->gmin >= ptr->bmax - ptr->bmin) + axis = GREEN; + else + axis = BLUE; + /* get histogram along longest axis */ + switch (axis) { + case RED: + histp = &hist2[ptr->rmin]; + for (ir = ptr->rmin; ir <= ptr->rmax; ++ir) { + *histp = 0; + for (ig = ptr->gmin; ig <= ptr->gmax; ++ig) { + iptr = &histogram[ir][ig][ptr->bmin]; + for (ib = ptr->bmin; ib <= ptr->bmax; ++ib) + *histp += *iptr++; + } + histp++; + } + first = ptr->rmin; + last = ptr->rmax; + break; + case GREEN: + histp = &hist2[ptr->gmin]; + for (ig = ptr->gmin; ig <= ptr->gmax; ++ig) { + *histp = 0; + for (ir = ptr->rmin; ir <= ptr->rmax; ++ir) { + iptr = &histogram[ir][ig][ptr->bmin]; + for (ib = ptr->bmin; ib <= ptr->bmax; ++ib) + *histp += *iptr++; + } + histp++; + } + first = ptr->gmin; + last = ptr->gmax; + break; + case BLUE: + histp = &hist2[ptr->bmin]; + for (ib = ptr->bmin; ib <= ptr->bmax; ++ib) { + *histp = 0; + for (ir = ptr->rmin; ir <= ptr->rmax; ++ir) { + iptr = &histogram[ir][ptr->gmin][ib]; + for (ig = ptr->gmin; ig <= ptr->gmax; ++ig) { + *histp += *iptr; + iptr += B_LEN; + } + } + histp++; + } + first = ptr->bmin; + last = ptr->bmax; + break; + } + /* find median point */ + sum2 = ptr->total / 2; + histp = &hist2[first]; + sum = 0; + for (i = first; i <= last && (sum += *histp++) < sum2; ++i) + ; + if (i == first) + i++; + + /* Create new box, re-allocate points */ + new = freeboxes; + freeboxes = new->next; + if (freeboxes) + freeboxes->prev = NULL; + if (usedboxes) + usedboxes->prev = new; + new->next = usedboxes; + usedboxes = new; + + histp = &hist2[first]; + for (sum1 = 0, j = first; j < i; j++) + sum1 += *histp++; + for (sum2 = 0, j = i; j <= last; j++) + sum2 += *histp++; + new->total = sum1; + ptr->total = sum2; + + new->rmin = ptr->rmin; + new->rmax = ptr->rmax; + new->gmin = ptr->gmin; + new->gmax = ptr->gmax; + new->bmin = ptr->bmin; + new->bmax = ptr->bmax; + switch (axis) { + case RED: + new->rmax = i-1; + ptr->rmin = i; + break; + case GREEN: + new->gmax = i-1; + ptr->gmin = i; + break; + case BLUE: + new->bmax = i-1; + ptr->bmin = i; + break; + } + shrinkbox(new); + shrinkbox(ptr); +} + +static void +shrinkbox(Colorbox* box) +{ + register uint32 *histp; + register int ir, ig, ib; + + if (box->rmax > box->rmin) { + for (ir = box->rmin; ir <= box->rmax; ++ir) + for (ig = box->gmin; ig <= box->gmax; ++ig) { + histp = &histogram[ir][ig][box->bmin]; + for (ib = box->bmin; ib <= box->bmax; ++ib) + if (*histp++ != 0) { + box->rmin = ir; + goto have_rmin; + } + } + have_rmin: + if (box->rmax > box->rmin) + for (ir = box->rmax; ir >= box->rmin; --ir) + for (ig = box->gmin; ig <= box->gmax; ++ig) { + histp = &histogram[ir][ig][box->bmin]; + ib = box->bmin; + for (; ib <= box->bmax; ++ib) + if (*histp++ != 0) { + box->rmax = ir; + goto have_rmax; + } + } + } +have_rmax: + if (box->gmax > box->gmin) { + for (ig = box->gmin; ig <= box->gmax; ++ig) + for (ir = box->rmin; ir <= box->rmax; ++ir) { + histp = &histogram[ir][ig][box->bmin]; + for (ib = box->bmin; ib <= box->bmax; ++ib) + if (*histp++ != 0) { + box->gmin = ig; + goto have_gmin; + } + } + have_gmin: + if (box->gmax > box->gmin) + for (ig = box->gmax; ig >= box->gmin; --ig) + for (ir = box->rmin; ir <= box->rmax; ++ir) { + histp = &histogram[ir][ig][box->bmin]; + ib = box->bmin; + for (; ib <= box->bmax; ++ib) + if (*histp++ != 0) { + box->gmax = ig; + goto have_gmax; + } + } + } +have_gmax: + if (box->bmax > box->bmin) { + for (ib = box->bmin; ib <= box->bmax; ++ib) + for (ir = box->rmin; ir <= box->rmax; ++ir) { + histp = &histogram[ir][box->gmin][ib]; + for (ig = box->gmin; ig <= box->gmax; ++ig) { + if (*histp != 0) { + box->bmin = ib; + goto have_bmin; + } + histp += B_LEN; + } + } + have_bmin: + if (box->bmax > box->bmin) + for (ib = box->bmax; ib >= box->bmin; --ib) + for (ir = box->rmin; ir <= box->rmax; ++ir) { + histp = &histogram[ir][box->gmin][ib]; + ig = box->gmin; + for (; ig <= box->gmax; ++ig) { + if (*histp != 0) { + box->bmax = ib; + goto have_bmax; + } + histp += B_LEN; + } + } + } +have_bmax: + ; +} + +static C_cell * +create_colorcell(int red, int green, int blue) +{ + register int ir, ig, ib, i; + register C_cell *ptr; + int mindist, next_n; + register int tmp, dist, n; + + ir = red >> (COLOR_DEPTH-C_DEPTH); + ig = green >> (COLOR_DEPTH-C_DEPTH); + ib = blue >> (COLOR_DEPTH-C_DEPTH); + ptr = (C_cell *)_TIFFmalloc(sizeof (C_cell)); + *(ColorCells + ir*C_LEN*C_LEN + ig*C_LEN + ib) = ptr; + ptr->num_ents = 0; + + /* + * Step 1: find all colors inside this cell, while we're at + * it, find distance of centermost point to furthest corner + */ + mindist = 99999999; + for (i = 0; i < num_colors; ++i) { + if (rm[i]>>(COLOR_DEPTH-C_DEPTH) != ir || + gm[i]>>(COLOR_DEPTH-C_DEPTH) != ig || + bm[i]>>(COLOR_DEPTH-C_DEPTH) != ib) + continue; + ptr->entries[ptr->num_ents][0] = i; + ptr->entries[ptr->num_ents][1] = 0; + ++ptr->num_ents; + tmp = rm[i] - red; + if (tmp < (MAX_COLOR/C_LEN/2)) + tmp = MAX_COLOR/C_LEN-1 - tmp; + dist = tmp*tmp; + tmp = gm[i] - green; + if (tmp < (MAX_COLOR/C_LEN/2)) + tmp = MAX_COLOR/C_LEN-1 - tmp; + dist += tmp*tmp; + tmp = bm[i] - blue; + if (tmp < (MAX_COLOR/C_LEN/2)) + tmp = MAX_COLOR/C_LEN-1 - tmp; + dist += tmp*tmp; + if (dist < mindist) + mindist = dist; + } + + /* + * Step 3: find all points within that distance to cell. + */ + for (i = 0; i < num_colors; ++i) { + if (rm[i] >> (COLOR_DEPTH-C_DEPTH) == ir && + gm[i] >> (COLOR_DEPTH-C_DEPTH) == ig && + bm[i] >> (COLOR_DEPTH-C_DEPTH) == ib) + continue; + dist = 0; + if ((tmp = red - rm[i]) > 0 || + (tmp = rm[i] - (red + MAX_COLOR/C_LEN-1)) > 0 ) + dist += tmp*tmp; + if ((tmp = green - gm[i]) > 0 || + (tmp = gm[i] - (green + MAX_COLOR/C_LEN-1)) > 0 ) + dist += tmp*tmp; + if ((tmp = blue - bm[i]) > 0 || + (tmp = bm[i] - (blue + MAX_COLOR/C_LEN-1)) > 0 ) + dist += tmp*tmp; + if (dist < mindist) { + ptr->entries[ptr->num_ents][0] = i; + ptr->entries[ptr->num_ents][1] = dist; + ++ptr->num_ents; + } + } + + /* + * Sort color cells by distance, use cheap exchange sort + */ + for (n = ptr->num_ents - 1; n > 0; n = next_n) { + next_n = 0; + for (i = 0; i < n; ++i) + if (ptr->entries[i][1] > ptr->entries[i+1][1]) { + tmp = ptr->entries[i][0]; + ptr->entries[i][0] = ptr->entries[i+1][0]; + ptr->entries[i+1][0] = tmp; + tmp = ptr->entries[i][1]; + ptr->entries[i][1] = ptr->entries[i+1][1]; + ptr->entries[i+1][1] = tmp; + next_n = i; + } + } + return (ptr); +} + +static void +map_colortable(void) +{ + register uint32 *histp = &histogram[0][0][0]; + register C_cell *cell; + register int j, tmp, d2, dist; + int ir, ig, ib, i; + + for (ir = 0; ir < B_LEN; ++ir) + for (ig = 0; ig < B_LEN; ++ig) + for (ib = 0; ib < B_LEN; ++ib, histp++) { + if (*histp == 0) { + *histp = -1; + continue; + } + cell = *(ColorCells + + (((ir>>(B_DEPTH-C_DEPTH)) << C_DEPTH*2) + + ((ig>>(B_DEPTH-C_DEPTH)) << C_DEPTH) + + (ib>>(B_DEPTH-C_DEPTH)))); + if (cell == NULL ) + cell = create_colorcell( + ir << COLOR_SHIFT, + ig << COLOR_SHIFT, + ib << COLOR_SHIFT); + dist = 9999999; + for (i = 0; i < cell->num_ents && + dist > cell->entries[i][1]; ++i) { + j = cell->entries[i][0]; + d2 = rm[j] - (ir << COLOR_SHIFT); + d2 *= d2; + tmp = gm[j] - (ig << COLOR_SHIFT); + d2 += tmp*tmp; + tmp = bm[j] - (ib << COLOR_SHIFT); + d2 += tmp*tmp; + if (d2 < dist) { + dist = d2; + *histp = j; + } + } + } +} + +/* + * straight quantization. Each pixel is mapped to the colors + * closest to it. Color values are rounded to the nearest color + * table entry. + */ +static void +quant(TIFF* in, TIFF* out) +{ + unsigned char *outline, *inputline; + register unsigned char *outptr, *inptr; + register uint32 i, j; + register int red, green, blue; + + inputline = (unsigned char *)_TIFFmalloc(TIFFScanlineSize(in)); + outline = (unsigned char *)_TIFFmalloc(imagewidth); + for (i = 0; i < imagelength; i++) { + if (TIFFReadScanline(in, inputline, i, 0) <= 0) + break; + inptr = inputline; + outptr = outline; + for (j = 0; j < imagewidth; j++) { + red = *inptr++ >> COLOR_SHIFT; + green = *inptr++ >> COLOR_SHIFT; + blue = *inptr++ >> COLOR_SHIFT; + *outptr++ = (unsigned char)histogram[red][green][blue]; + } + if (TIFFWriteScanline(out, outline, i, 0) < 0) + break; + } + _TIFFfree(inputline); + _TIFFfree(outline); +} + +#define SWAP(type,a,b) { type p; p = a; a = b; b = p; } + +#define GetInputLine(tif, row, bad) \ + if (TIFFReadScanline(tif, inputline, row, 0) <= 0) \ + bad; \ + inptr = inputline; \ + nextptr = nextline; \ + for (j = 0; j < imagewidth; ++j) { \ + *nextptr++ = *inptr++; \ + *nextptr++ = *inptr++; \ + *nextptr++ = *inptr++; \ + } +#define GetComponent(raw, cshift, c) \ + cshift = raw; \ + if (cshift < 0) \ + cshift = 0; \ + else if (cshift >= MAX_COLOR) \ + cshift = MAX_COLOR-1; \ + c = cshift; \ + cshift >>= COLOR_SHIFT; + +static void +quant_fsdither(TIFF* in, TIFF* out) +{ + unsigned char *outline, *inputline, *inptr; + short *thisline, *nextline; + register unsigned char *outptr; + register short *thisptr, *nextptr; + register uint32 i, j; + uint32 imax, jmax; + int lastline, lastpixel; + + imax = imagelength - 1; + jmax = imagewidth - 1; + inputline = (unsigned char *)_TIFFmalloc(TIFFScanlineSize(in)); + thisline = (short *)_TIFFmalloc(imagewidth * 3 * sizeof (short)); + nextline = (short *)_TIFFmalloc(imagewidth * 3 * sizeof (short)); + outline = (unsigned char *) _TIFFmalloc(TIFFScanlineSize(out)); + + GetInputLine(in, 0, goto bad); /* get first line */ + for (i = 1; i <= imagelength; ++i) { + SWAP(short *, thisline, nextline); + lastline = (i >= imax); + if (i <= imax) + GetInputLine(in, i, break); + thisptr = thisline; + nextptr = nextline; + outptr = outline; + for (j = 0; j < imagewidth; ++j) { + int red, green, blue; + register int oval, r2, g2, b2; + + lastpixel = (j == jmax); + GetComponent(*thisptr++, r2, red); + GetComponent(*thisptr++, g2, green); + GetComponent(*thisptr++, b2, blue); + oval = histogram[r2][g2][b2]; + if (oval == -1) { + int ci; + register int cj, tmp, d2, dist; + register C_cell *cell; + + cell = *(ColorCells + + (((r2>>(B_DEPTH-C_DEPTH)) << C_DEPTH*2) + + ((g2>>(B_DEPTH-C_DEPTH)) << C_DEPTH ) + + (b2>>(B_DEPTH-C_DEPTH)))); + if (cell == NULL) + cell = create_colorcell(red, + green, blue); + dist = 9999999; + for (ci = 0; ci < cell->num_ents && dist > cell->entries[ci][1]; ++ci) { + cj = cell->entries[ci][0]; + d2 = (rm[cj] >> COLOR_SHIFT) - r2; + d2 *= d2; + tmp = (gm[cj] >> COLOR_SHIFT) - g2; + d2 += tmp*tmp; + tmp = (bm[cj] >> COLOR_SHIFT) - b2; + d2 += tmp*tmp; + if (d2 < dist) { + dist = d2; + oval = cj; + } + } + histogram[r2][g2][b2] = oval; + } + *outptr++ = oval; + red -= rm[oval]; + green -= gm[oval]; + blue -= bm[oval]; + if (!lastpixel) { + thisptr[0] += blue * 7 / 16; + thisptr[1] += green * 7 / 16; + thisptr[2] += red * 7 / 16; + } + if (!lastline) { + if (j != 0) { + nextptr[-3] += blue * 3 / 16; + nextptr[-2] += green * 3 / 16; + nextptr[-1] += red * 3 / 16; + } + nextptr[0] += blue * 5 / 16; + nextptr[1] += green * 5 / 16; + nextptr[2] += red * 5 / 16; + if (!lastpixel) { + nextptr[3] += blue / 16; + nextptr[4] += green / 16; + nextptr[5] += red / 16; + } + nextptr += 3; + } + } + if (TIFFWriteScanline(out, outline, i-1, 0) < 0) + break; + } +bad: + _TIFFfree(inputline); + _TIFFfree(thisline); + _TIFFfree(nextline); + _TIFFfree(outline); +} +/* + * Local Variables: + * mode: c + * c-basic-offset: 8 + * fill-column: 78 + * End: + */ |