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authorJörg Frings-Fürst <debian@jff-webhosting.net>2014-10-06 14:00:40 +0200
committerJörg Frings-Fürst <debian@jff-webhosting.net>2014-10-06 14:00:40 +0200
commit6e9c41a892ed0e0da326e0278b3221ce3f5713b8 (patch)
tree2e301d871bbeeb44aa57ff9cc070fcf3be484487 /sanei/sanei_magic.c
Initial import of sane-backends version 1.0.24-1.2
Diffstat (limited to 'sanei/sanei_magic.c')
-rw-r--r--sanei/sanei_magic.c1941
1 files changed, 1941 insertions, 0 deletions
diff --git a/sanei/sanei_magic.c b/sanei/sanei_magic.c
new file mode 100644
index 0000000..167d7dd
--- /dev/null
+++ b/sanei/sanei_magic.c
@@ -0,0 +1,1941 @@
+/*
+ * sanei_magic - Image processing functions for despeckle, deskew, and autocrop
+
+ Copyright (C) 2009 m. allan noah
+
+ This file is part of the SANE package.
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ MA 02111-1307, USA.
+
+ As a special exception, the authors of SANE give permission for
+ additional uses of the libraries contained in this release of SANE.
+
+ The exception is that, if you link a SANE library with other files
+ to produce an executable, this does not by itself cause the
+ resulting executable to be covered by the GNU General Public
+ License. Your use of that executable is in no way restricted on
+ account of linking the SANE library code into it.
+
+ This exception does not, however, invalidate any other reasons why
+ the executable file might be covered by the GNU General Public
+ License.
+
+ If you submit changes to SANE to the maintainers to be included in
+ a subsequent release, you agree by submitting the changes that
+ those changes may be distributed with this exception intact.
+
+ If you write modifications of your own for SANE, it is your choice
+ whether to permit this exception to apply to your modifications.
+ If you do not wish that, delete this exception notice.
+ */
+
+#include "../include/sane/config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <math.h>
+
+#define BACKEND_NAME sanei_magic /* name of this module for debugging */
+
+#include "../include/sane/sane.h"
+#include "../include/sane/sanei_debug.h"
+#include "../include/sane/sanei_magic.h"
+
+/* prototypes for utility functions defined at bottom of file */
+int * sanei_magic_getTransY (
+ SANE_Parameters * params, int dpi, SANE_Byte * buffer, int top);
+
+int * sanei_magic_getTransX (
+ SANE_Parameters * params, int dpi, SANE_Byte * buffer, int left);
+
+static SANE_Status getTopEdge (int width, int height, int resolution,
+ int * buff, double * finSlope, int * finXInter, int * finYInter);
+
+static SANE_Status getLeftEdge (int width, int height, int * top, int * bot,
+ double slope, int * finXInter, int * finYInter);
+
+static SANE_Status getLine (int height, int width, int * buff,
+ int slopes, double minSlope, double maxSlope,
+ int offsets, int minOffset, int maxOffset,
+ double * finSlope, int * finOffset, int * finDensity);
+
+void
+sanei_magic_init( void )
+{
+ DBG_INIT();
+}
+
+/* find small spots and replace them with image background color */
+SANE_Status
+sanei_magic_despeck (SANE_Parameters * params, SANE_Byte * buffer,
+ SANE_Int diam)
+{
+
+ SANE_Status ret = SANE_STATUS_GOOD;
+
+ int pw = params->pixels_per_line;
+ int bw = params->bytes_per_line;
+ int h = params->lines;
+ int bt = bw*h;
+
+ int i,j,k,l,n;
+
+ DBG (10, "sanei_magic_despeck: start\n");
+
+ if(params->format == SANE_FRAME_RGB){
+
+ for(i=bw; i<bt-bw-(bw*diam); i+=bw){
+ for(j=1; j<pw-1-diam; j++){
+
+ int thresh = 255*3;
+ int outer[] = {0,0,0};
+ int hits = 0;
+
+ /* loop over rows and columns in window */
+ /* find darkest pixel */
+ for(k=0; k<diam; k++){
+ for(l=0; l<diam; l++){
+ int tmp = 0;
+
+ for(n=0; n<3; n++){
+ tmp += buffer[i + j*3 + k*bw + l*3 + n];
+ }
+
+ if(tmp < thresh)
+ thresh = tmp;
+ }
+ }
+
+ /* convert darkest pixel into a brighter threshold */
+ thresh = (thresh + 255*3 + 255*3)/3;
+
+ /*loop over rows and columns around window */
+ for(k=-1; k<diam+1; k++){
+ for(l=-1; l<diam+1; l++){
+
+ int tmp[3];
+
+ /* dont count pixels in the window */
+ if(k != -1 && k != diam && l != -1 && l != diam)
+ continue;
+
+ for(n=0; n<3; n++){
+ tmp[n] = buffer[i + j*3 + k*bw + l*3 + n];
+ outer[n] += tmp[n];
+ }
+ if(tmp[0]+tmp[1]+tmp[2] < thresh){
+ hits++;
+ break;
+ }
+ }
+ }
+
+ /*no hits, overwrite with avg surrounding color*/
+ if(!hits){
+
+ /* per channel replacement color */
+ for(n=0; n<3; n++){
+ outer[n] /= (4*diam + 4);
+ }
+
+ for(k=0; k<diam; k++){
+ for(l=0; l<diam; l++){
+ for(n=0; n<3; n++){
+ buffer[i + j*3 + k*bw + l*3 + n] = outer[n];
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+
+ else if(params->format == SANE_FRAME_GRAY && params->depth == 8){
+ for(i=bw; i<bt-bw-(bw*diam); i+=bw){
+ for(j=1; j<pw-1-diam; j++){
+
+ int thresh = 255;
+ int outer = 0;
+ int hits = 0;
+
+ for(k=0; k<diam; k++){
+ for(l=0; l<diam; l++){
+ if(buffer[i + j + k*bw + l] < thresh)
+ thresh = buffer[i + j + k*bw + l];
+ }
+ }
+
+ /* convert darkest pixel into a brighter threshold */
+ thresh = (thresh + 255 + 255)/3;
+
+ /*loop over rows and columns around window */
+ for(k=-1; k<diam+1; k++){
+ for(l=-1; l<diam+1; l++){
+
+ int tmp = 0;
+
+ /* dont count pixels in the window */
+ if(k != -1 && k != diam && l != -1 && l != diam)
+ continue;
+
+ tmp = buffer[i + j + k*bw + l];
+
+ if(tmp < thresh){
+ hits++;
+ break;
+ }
+
+ outer += tmp;
+ }
+ }
+
+ /*no hits, overwrite with avg surrounding color*/
+ if(!hits){
+ /* replacement color */
+ outer /= (4*diam + 4);
+
+ for(k=0; k<diam; k++){
+ for(l=0; l<diam; l++){
+ buffer[i + j + k*bw + l] = outer;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ else if(params->format == SANE_FRAME_GRAY && params->depth == 1){
+ for(i=bw; i<bt-bw-(bw*diam); i+=bw){
+ for(j=1; j<pw-1-diam; j++){
+
+ int curr = 0;
+ int hits = 0;
+
+ for(k=0; k<diam; k++){
+ for(l=0; l<diam; l++){
+ curr += buffer[i + k*bw + (j+l)/8] >> (7-(j+l)%8) & 1;
+ }
+ }
+
+ if(!curr)
+ continue;
+
+ /*loop over rows and columns around window */
+ for(k=-1; k<diam+1; k++){
+ for(l=-1; l<diam+1; l++){
+
+ /* dont count pixels in the window */
+ if(k != -1 && k != diam && l != -1 && l != diam)
+ continue;
+
+ hits += buffer[i + k*bw + (j+l)/8] >> (7-(j+l)%8) & 1;
+
+ if(hits)
+ break;
+ }
+ }
+
+ /*no hits, overwrite with white*/
+ if(!hits){
+ for(k=0; k<diam; k++){
+ for(l=0; l<diam; l++){
+ buffer[i + k*bw + (j+l)/8] &= ~(1 << (7-(j+l)%8));
+ }
+ }
+ }
+ }
+ }
+ }
+
+ else{
+ DBG (5, "sanei_magic_despeck: unsupported format/depth\n");
+ ret = SANE_STATUS_INVAL;
+ }
+
+ DBG (10, "sanei_magic_despeck: finish\n");
+ return ret;
+}
+
+/* find likely edges of media inside image background color */
+SANE_Status
+sanei_magic_findEdges(SANE_Parameters * params, SANE_Byte * buffer,
+ int dpiX, int dpiY, int * top, int * bot, int * left, int * right)
+{
+
+ SANE_Status ret = SANE_STATUS_GOOD;
+
+ int width = params->pixels_per_line;
+ int height = params->lines;
+
+ int * topBuf = NULL, * botBuf = NULL;
+ int * leftBuf = NULL, * rightBuf = NULL;
+
+ int topCount = 0, botCount = 0;
+ int leftCount = 0, rightCount = 0;
+
+ int i;
+
+ DBG (10, "sanei_magic_findEdges: start\n");
+
+ /* get buffers to find sides and bottom */
+ topBuf = sanei_magic_getTransY(params,dpiY,buffer,1);
+ if(!topBuf){
+ DBG (5, "sanei_magic_findEdges: no topBuf\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ botBuf = sanei_magic_getTransY(params,dpiY,buffer,0);
+ if(!botBuf){
+ DBG (5, "sanei_magic_findEdges: no botBuf\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ leftBuf = sanei_magic_getTransX(params,dpiX,buffer,1);
+ if(!leftBuf){
+ DBG (5, "sanei_magic_findEdges: no leftBuf\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ rightBuf = sanei_magic_getTransX(params,dpiX,buffer,0);
+ if(!rightBuf){
+ DBG (5, "sanei_magic_findEdges: no rightBuf\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ /* loop thru left and right lists, look for top and bottom extremes */
+ *top = height;
+ for(i=0; i<height; i++){
+ if(rightBuf[i] > leftBuf[i]){
+ if(*top > i){
+ *top = i;
+ }
+
+ topCount++;
+ if(topCount > 3){
+ break;
+ }
+ }
+ else{
+ topCount = 0;
+ *top = height;
+ }
+ }
+
+ *bot = -1;
+ for(i=height-1; i>=0; i--){
+ if(rightBuf[i] > leftBuf[i]){
+ if(*bot < i){
+ *bot = i;
+ }
+
+ botCount++;
+ if(botCount > 3){
+ break;
+ }
+ }
+ else{
+ botCount = 0;
+ *bot = -1;
+ }
+ }
+
+ /* could not find top/bot edges */
+ if(*top > *bot){
+ DBG (5, "sanei_magic_findEdges: bad t/b edges\n");
+ ret = SANE_STATUS_UNSUPPORTED;
+ goto cleanup;
+ }
+
+ /* loop thru top and bottom lists, look for l and r extremes
+ * NOTE: We dont look above the top or below the bottom found previously.
+ * This prevents issues with adf scanners that pad the image after the
+ * paper runs out (usually with white) */
+ DBG (5, "sanei_magic_findEdges: bb0:%d tb0:%d b:%d t:%d\n",
+ botBuf[0], topBuf[0], *bot, *top);
+
+ *left = width;
+ for(i=0; i<width; i++){
+ if(botBuf[i] > topBuf[i] && (botBuf[i]-10 < *bot || topBuf[i]+10 > *top)){
+ if(*left > i){
+ *left = i;
+ }
+
+ leftCount++;
+ if(leftCount > 3){
+ break;
+ }
+ }
+ else{
+ leftCount = 0;
+ *left = width;
+ }
+ }
+
+ *right = -1;
+ for(i=width-1; i>=0; i--){
+ if(botBuf[i] > topBuf[i] && (botBuf[i]-10 < *bot || topBuf[i]+10 > *top)){
+ if(*right < i){
+ *right = i;
+ }
+
+ rightCount++;
+ if(rightCount > 3){
+ break;
+ }
+ }
+ else{
+ rightCount = 0;
+ *right = -1;
+ }
+ }
+
+ /* could not find left/right edges */
+ if(*left > *right){
+ DBG (5, "sanei_magic_findEdges: bad l/r edges\n");
+ ret = SANE_STATUS_UNSUPPORTED;
+ goto cleanup;
+ }
+
+ DBG (15, "sanei_magic_findEdges: t:%d b:%d l:%d r:%d\n",
+ *top,*bot,*left,*right);
+
+ cleanup:
+ if(topBuf)
+ free(topBuf);
+ if(botBuf)
+ free(botBuf);
+ if(leftBuf)
+ free(leftBuf);
+ if(rightBuf)
+ free(rightBuf);
+
+ DBG (10, "sanei_magic_findEdges: finish\n");
+ return ret;
+}
+
+/* crop image to given size. updates params with new dimensions */
+SANE_Status
+sanei_magic_crop(SANE_Parameters * params, SANE_Byte * buffer,
+ int top, int bot, int left, int right)
+{
+
+ SANE_Status ret = SANE_STATUS_GOOD;
+
+ int bwidth = params->bytes_per_line;
+
+ int pixels = 0;
+ int bytes = 0;
+ unsigned char * line = NULL;
+ int pos = 0, i;
+
+ DBG (10, "sanei_magic_crop: start\n");
+
+ /*convert left and right to bytes, figure new byte and pixel width */
+ if(params->format == SANE_FRAME_RGB){
+ pixels = right-left;
+ bytes = pixels * 3;
+ left *= 3;
+ right *= 3;
+ }
+ else if(params->format == SANE_FRAME_GRAY && params->depth == 8){
+ pixels = right-left;
+ bytes = right-left;
+ }
+ else if(params->format == SANE_FRAME_GRAY && params->depth == 1){
+ left /= 8;
+ right = (right+7)/8;
+ bytes = right-left;
+ pixels = bytes * 8;
+ }
+ else{
+ DBG (5, "sanei_magic_crop: unsupported format/depth\n");
+ ret = SANE_STATUS_INVAL;
+ goto cleanup;
+ }
+
+ DBG (15, "sanei_magic_crop: l:%d r:%d p:%d b:%d\n",left,right,pixels,bytes);
+
+ line = malloc(bytes);
+ if(!line){
+ DBG (5, "sanei_magic_crop: no line\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ for(i=top; i<bot; i++){
+ memcpy(line, buffer + i*bwidth + left, bytes);
+ memcpy(buffer + pos, line, bytes);
+ pos += bytes;
+ }
+
+ /* update the params struct with the new image size */
+ params->lines = bot-top;
+ params->pixels_per_line = pixels;
+ params->bytes_per_line = bytes;
+
+ cleanup:
+ if(line)
+ free(line);
+
+ DBG (10, "sanei_magic_crop: finish\n");
+ return ret;
+}
+
+/* find angle of media rotation against image background */
+SANE_Status
+sanei_magic_findSkew(SANE_Parameters * params, SANE_Byte * buffer,
+ int dpiX, int dpiY, int * centerX, int * centerY, double * finSlope)
+{
+ SANE_Status ret = SANE_STATUS_GOOD;
+
+ int pwidth = params->pixels_per_line;
+ int height = params->lines;
+
+ double TSlope = 0;
+ int TXInter = 0;
+ int TYInter = 0;
+ double TSlopeHalf = 0;
+ int TOffsetHalf = 0;
+
+ double LSlope = 0;
+ int LXInter = 0;
+ int LYInter = 0;
+ double LSlopeHalf = 0;
+ int LOffsetHalf = 0;
+
+ int rotateX = 0;
+ int rotateY = 0;
+
+ int * topBuf = NULL, * botBuf = NULL;
+
+ DBG (10, "sanei_magic_findSkew: start\n");
+
+ dpiX=dpiX;
+
+ /* get buffers for edge detection */
+ topBuf = sanei_magic_getTransY(params,dpiY,buffer,1);
+ if(!topBuf){
+ DBG (5, "sanei_magic_findSkew: cant gTY\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ botBuf = sanei_magic_getTransY(params,dpiY,buffer,0);
+ if(!botBuf){
+ DBG (5, "sanei_magic_findSkew: cant gTY\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ /* find best top line */
+ ret = getTopEdge (pwidth, height, dpiY, topBuf,
+ &TSlope, &TXInter, &TYInter);
+ if(ret){
+ DBG(5,"sanei_magic_findSkew: gTE error: %d",ret);
+ goto cleanup;
+ }
+ DBG(15,"top: %04.04f %d %d\n",TSlope,TXInter,TYInter);
+
+ /* slope is too shallow, don't want to divide by 0 */
+ if(fabs(TSlope) < 0.0001){
+ DBG(15,"sanei_magic_findSkew: slope too shallow: %0.08f\n",TSlope);
+ ret = SANE_STATUS_UNSUPPORTED;
+ goto cleanup;
+ }
+
+ /* find best left line, perpendicular to top line */
+ LSlope = (double)-1/TSlope;
+ ret = getLeftEdge (pwidth, height, topBuf, botBuf, LSlope,
+ &LXInter, &LYInter);
+ if(ret){
+ DBG(5,"sanei_magic_findSkew: gLE error: %d",ret);
+ goto cleanup;
+ }
+ DBG(15,"sanei_magic_findSkew: left: %04.04f %d %d\n",LSlope,LXInter,LYInter);
+
+ /* find point about which to rotate */
+ TSlopeHalf = tan(atan(TSlope)/2);
+ TOffsetHalf = LYInter;
+ DBG(15,"sanei_magic_findSkew: top half: %04.04f %d\n",TSlopeHalf,TOffsetHalf);
+
+ LSlopeHalf = tan((atan(LSlope) + ((LSlope < 0)?-M_PI_2:M_PI_2))/2);
+ LOffsetHalf = - LSlopeHalf * TXInter;
+ DBG(15,"sanei_magic_findSkew: left half: %04.04f %d\n",LSlopeHalf,LOffsetHalf);
+
+ rotateX = (LOffsetHalf-TOffsetHalf) / (TSlopeHalf-LSlopeHalf);
+ rotateY = TSlopeHalf * rotateX + TOffsetHalf;
+ DBG(15,"sanei_magic_findSkew: rotate: %d %d\n",rotateX,rotateY);
+
+ *centerX = rotateX;
+ *centerY = rotateY;
+ *finSlope = TSlope;
+
+ cleanup:
+ if(topBuf)
+ free(topBuf);
+ if(botBuf)
+ free(botBuf);
+
+ DBG (10, "sanei_magic_findSkew: finish\n");
+ return ret;
+}
+
+/* function to do a simple rotation by a given slope, around
+ * a given point. The point can be outside of image to get
+ * proper edge alignment. Unused areas filled with bg color
+ * FIXME: Do in-place rotation to save memory */
+SANE_Status
+sanei_magic_rotate (SANE_Parameters * params, SANE_Byte * buffer,
+ int centerX, int centerY, double slope, int bg_color)
+{
+
+ SANE_Status ret = SANE_STATUS_GOOD;
+
+ double slopeRad = -atan(slope);
+ double slopeSin = sin(slopeRad);
+ double slopeCos = cos(slopeRad);
+
+ int pwidth = params->pixels_per_line;
+ int bwidth = params->bytes_per_line;
+ int height = params->lines;
+ int depth = 1;
+
+ unsigned char * outbuf;
+ int i, j, k;
+
+ DBG(10,"sanei_magic_rotate: start: %d %d\n",centerX,centerY);
+
+ outbuf = malloc(bwidth*height);
+ if(!outbuf){
+ DBG(15,"sanei_magic_rotate: no outbuf\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ if(params->format == SANE_FRAME_RGB ||
+ (params->format == SANE_FRAME_GRAY && params->depth == 8)
+ ){
+
+ if(params->format == SANE_FRAME_RGB)
+ depth = 3;
+
+ memset(outbuf,bg_color,bwidth*height);
+
+ for (i=0; i<height; i++) {
+ int shiftY = centerY - i;
+
+ for (j=0; j<pwidth; j++) {
+ int shiftX = centerX - j;
+ int sourceX, sourceY;
+
+ sourceX = centerX - (int)(shiftX * slopeCos + shiftY * slopeSin);
+ if (sourceX < 0 || sourceX >= pwidth)
+ continue;
+
+ sourceY = centerY + (int)(-shiftY * slopeCos + shiftX * slopeSin);
+ if (sourceY < 0 || sourceY >= height)
+ continue;
+
+ for (k=0; k<depth; k++) {
+ outbuf[i*bwidth+j*depth+k]
+ = buffer[sourceY*bwidth+sourceX*depth+k];
+ }
+ }
+ }
+ }
+
+ else if(params->format == SANE_FRAME_GRAY && params->depth == 1){
+
+ if(bg_color)
+ bg_color = 0xff;
+
+ memset(outbuf,bg_color,bwidth*height);
+
+ for (i=0; i<height; i++) {
+ int shiftY = centerY - i;
+
+ for (j=0; j<pwidth; j++) {
+ int shiftX = centerX - j;
+ int sourceX, sourceY;
+
+ sourceX = centerX - (int)(shiftX * slopeCos + shiftY * slopeSin);
+ if (sourceX < 0 || sourceX >= pwidth)
+ continue;
+
+ sourceY = centerY + (int)(-shiftY * slopeCos + shiftX * slopeSin);
+ if (sourceY < 0 || sourceY >= height)
+ continue;
+
+ /* wipe out old bit */
+ outbuf[i*bwidth + j/8] &= ~(1 << (7-(j%8)));
+
+ /* fill in new bit */
+ outbuf[i*bwidth + j/8] |=
+ ((buffer[sourceY*bwidth + sourceX/8]
+ >> (7-(sourceX%8))) & 1) << (7-(j%8));
+ }
+ }
+ }
+ else{
+ DBG (5, "sanei_magic_rotate: unsupported format/depth\n");
+ ret = SANE_STATUS_INVAL;
+ goto cleanup;
+ }
+
+ memcpy(buffer,outbuf,bwidth*height);
+
+ cleanup:
+
+ if(outbuf)
+ free(outbuf);
+
+ DBG(10,"sanei_magic_rotate: finish\n");
+
+ return 0;
+}
+
+SANE_Status
+sanei_magic_isBlank (SANE_Parameters * params, SANE_Byte * buffer,
+ double thresh)
+{
+ SANE_Status ret = SANE_STATUS_GOOD;
+ double imagesum = 0;
+ int i, j;
+
+ DBG(10,"sanei_magic_isBlank: start: %f\n",thresh);
+
+ /*convert thresh from percent (0-100) to 0-1 range*/
+ thresh /= 100;
+
+ if(params->format == SANE_FRAME_RGB ||
+ (params->format == SANE_FRAME_GRAY && params->depth == 8)
+ ){
+
+ /* loop over all rows, find density of each */
+ for(i=0; i<params->lines; i++){
+ int rowsum = 0;
+ SANE_Byte * ptr = buffer + params->bytes_per_line*i;
+
+ /* loop over all columns, sum the 'darkness' of the pixels */
+ for(j=0; j<params->bytes_per_line; j++){
+ rowsum += 255 - ptr[j];
+ }
+
+ imagesum += (double)rowsum/params->bytes_per_line/255;
+ }
+
+ }
+ else if(params->format == SANE_FRAME_GRAY && params->depth == 1){
+
+ /* loop over all rows, find density of each */
+ for(i=0; i<params->lines; i++){
+ int rowsum = 0;
+ SANE_Byte * ptr = buffer + params->bytes_per_line*i;
+
+ /* loop over all columns, sum the pixels */
+ for(j=0; j<params->pixels_per_line; j++){
+ rowsum += ptr[j/8] >> (7-(j%8)) & 1;
+ }
+
+ imagesum += (double)rowsum/params->pixels_per_line;
+ }
+
+ }
+ else{
+ DBG (5, "sanei_magic_isBlank: unsupported format/depth\n");
+ ret = SANE_STATUS_INVAL;
+ goto cleanup;
+ }
+
+ DBG (5, "sanei_magic_isBlank: sum:%f lines:%d thresh:%f density:%f\n",
+ imagesum,params->lines,thresh,imagesum/params->lines);
+
+ if(imagesum/params->lines <= thresh){
+ DBG (5, "sanei_magic_isBlank: blank!\n");
+ ret = SANE_STATUS_NO_DOCS;
+ }
+
+ cleanup:
+
+ DBG(10,"sanei_magic_isBlank: finish\n");
+
+ return ret;
+}
+
+/* Divide the image into 1/2 inch squares, skipping a 1/4 inch
+ * margin on all sides. If all squares are under the user's density,
+ * signal our caller to skip the image entirely, by returning
+ * SANE_STATUS_NO_DOCS */
+SANE_Status
+sanei_magic_isBlank2 (SANE_Parameters * params, SANE_Byte * buffer,
+ int dpiX, int dpiY, double thresh)
+{
+ int xb,yb,x,y;
+
+ /* .25 inch, rounded down to 8 pixel */
+ int xquarter = dpiX/4/8*8;
+ int yquarter = dpiY/4/8*8;
+ int xhalf = xquarter*2;
+ int yhalf = yquarter*2;
+ int blockpix = xhalf*yhalf;
+ int xblocks = (params->pixels_per_line-xhalf)/xhalf;
+ int yblocks = (params->lines-yhalf)/yhalf;
+
+ /*convert thresh from percent (0-100) to 0-1 range*/
+ thresh /= 100;
+
+ DBG (10, "sanei_magic_isBlank2: start %d %d %f %d\n",xhalf,yhalf,thresh,blockpix);
+
+ if(params->depth == 8 &&
+ (params->format == SANE_FRAME_RGB || params->format == SANE_FRAME_GRAY)
+ ){
+
+ int Bpp = params->format == SANE_FRAME_RGB ? 3 : 1;
+
+ for(yb=0; yb<yblocks; yb++){
+ for(xb=0; xb<xblocks; xb++){
+
+ /*count dark pix in this block*/
+ double blocksum = 0;
+
+ for(y=0; y<yhalf; y++){
+
+ /* skip the top and left 1/4 inch */
+ int offset = (yquarter + yb*yhalf + y) * params->bytes_per_line
+ + (xquarter + xb*xhalf) * Bpp;
+ SANE_Byte * ptr = buffer + offset;
+
+ /*count darkness of pix in this row*/
+ int rowsum = 0;
+
+ for(x=0; x<xhalf*Bpp; x++){
+ rowsum += 255 - ptr[x];
+ }
+
+ blocksum += (double)rowsum/(xhalf*Bpp)/255;
+ }
+
+ /* block was darker than thresh, keep image */
+ if(blocksum/yhalf > thresh){
+ DBG (15, "sanei_magic_isBlank2: not blank %f %d %d\n", blocksum/yhalf, yb, xb);
+ return SANE_STATUS_GOOD;
+ }
+ DBG (20, "sanei_magic_isBlank2: block blank %f %d %d\n", blocksum/yhalf, yb, xb);
+ }
+ }
+ }
+ else if(params->format == SANE_FRAME_GRAY && params->depth == 1){
+
+ for(yb=0; yb<yblocks; yb++){
+ for(xb=0; xb<xblocks; xb++){
+
+ /*count dark pix in this block*/
+ double blocksum = 0;
+
+ for(y=0; y<yhalf; y++){
+
+ /* skip the top and left 1/4 inch */
+ int offset = (yquarter + yb*yhalf + y) * params->bytes_per_line
+ + (xquarter + xb*xhalf) / 8;
+ SANE_Byte * ptr = buffer + offset;
+
+ /*count darkness of pix in this row*/
+ int rowsum = 0;
+
+ for(x=0; x<xhalf; x++){
+ rowsum += ptr[x/8] >> (7-(x%8)) & 1;
+ }
+
+ blocksum += (double)rowsum/xhalf;
+ }
+
+ /* block was darker than thresh, keep image */
+ if(blocksum/yhalf > thresh){
+ DBG (15, "sanei_magic_isBlank2: not blank %f %d %d\n", blocksum/yhalf, yb, xb);
+ return SANE_STATUS_GOOD;
+ }
+ DBG (20, "sanei_magic_isBlank2: block blank %f %d %d\n", blocksum/yhalf, yb, xb);
+ }
+ }
+ }
+ else{
+ DBG (5, "sanei_magic_isBlank2: unsupported format/depth\n");
+ return SANE_STATUS_INVAL;
+ }
+
+ DBG (10, "sanei_magic_isBlank2: returning blank\n");
+ return SANE_STATUS_NO_DOCS;
+}
+
+SANE_Status
+sanei_magic_findTurn(SANE_Parameters * params, SANE_Byte * buffer,
+ int dpiX, int dpiY, int * angle)
+{
+ SANE_Status ret = SANE_STATUS_GOOD;
+ int i, j, k;
+ int depth = 1;
+ int htrans=0, vtrans=0;
+ int htot=0, vtot=0;
+
+ DBG(10,"sanei_magic_findTurn: start\n");
+
+ if(params->format == SANE_FRAME_RGB ||
+ (params->format == SANE_FRAME_GRAY && params->depth == 8)
+ ){
+
+ if(params->format == SANE_FRAME_RGB)
+ depth = 3;
+
+ /* loop over some rows, count segment lengths */
+ for(i=0; i<params->lines; i+=dpiY/20){
+ SANE_Byte * ptr = buffer + params->bytes_per_line*i;
+ int color = 0;
+ int len = 0;
+ int sum = 0;
+
+ /* loop over all columns */
+ for(j=0; j<params->pixels_per_line; j++){
+ int curr = 0;
+
+ /*convert color to gray*/
+ for (k=0; k<depth; k++) {
+ curr += ptr[j*depth+k];
+ }
+ curr /= depth;
+
+ /*convert gray to binary (with hysteresis) */
+ curr = (curr < 100)?1:
+ (curr > 156)?0:color;
+
+ /*count segment length*/
+ if(curr != color || j==params->pixels_per_line-1){
+ sum += len * len/5;
+ len = 0;
+ color = curr;
+ }
+ else{
+ len++;
+ }
+ }
+
+ htot++;
+ htrans += (double)sum/params->pixels_per_line;
+ }
+
+ /* loop over some cols, count dark vs light transitions */
+ for(i=0; i<params->pixels_per_line; i+=dpiX/20){
+ SANE_Byte * ptr = buffer + i*depth;
+ int color = 0;
+ int len = 0;
+ int sum = 0;
+
+ /* loop over all rows */
+ for(j=0; j<params->lines; j++){
+ int curr = 0;
+
+ /*convert color to gray*/
+ for (k=0; k<depth; k++) {
+ curr += ptr[j*params->bytes_per_line+k];
+ }
+ curr /= depth;
+
+ /*convert gray to binary (with hysteresis) */
+ curr = (curr < 100)?1:
+ (curr > 156)?0:color;
+
+ /*count segment length*/
+ if(curr != color || j==params->lines-1){
+ sum += len * len/5;
+ len = 0;
+ color = curr;
+ }
+ else{
+ len++;
+ }
+ }
+
+ vtot++;
+ vtrans += (double)sum/params->lines;
+ }
+
+ }
+ else if(params->format == SANE_FRAME_GRAY && params->depth == 1){
+
+ /* loop over some rows, count segment lengths */
+ for(i=0; i<params->lines; i+=dpiY/30){
+ SANE_Byte * ptr = buffer + params->bytes_per_line*i;
+ int color = 0;
+ int len = 0;
+ int sum = 0;
+
+ /* loop over all columns */
+ for(j=0; j<params->pixels_per_line; j++){
+ int curr = ptr[j/8] >> (7-(j%8)) & 1;
+
+ /*count segment length*/
+ if(curr != color || j==params->pixels_per_line-1){
+ sum += len * len/5;
+ len = 0;
+ color = curr;
+ }
+ else{
+ len++;
+ }
+ }
+
+ htot++;
+ htrans += (double)sum/params->pixels_per_line;
+ }
+
+ /* loop over some cols, count dark vs light transitions */
+ for(i=0; i<params->pixels_per_line; i+=dpiX/30){
+ SANE_Byte * ptr = buffer;
+ int color = 0;
+ int len = 0;
+ int sum = 0;
+
+ /* loop over all rows */
+ for(j=0; j<params->lines; j++){
+ int curr = ptr[j*params->bytes_per_line + i/8] >> (7-(i%8)) & 1;
+
+ /*count segment length*/
+ if(curr != color || j==params->lines-1){
+ sum += len * len/5;
+ len = 0;
+ color = curr;
+ }
+ else{
+ len++;
+ }
+ }
+
+ vtot++;
+ vtrans += (double)sum/params->lines;
+ }
+
+ }
+ else{
+ DBG (5, "sanei_magic_findTurn: unsupported format/depth\n");
+ ret = SANE_STATUS_INVAL;
+ goto cleanup;
+ }
+
+ DBG (10, "sanei_magic_findTurn: vtrans=%d vtot=%d vfrac=%f htrans=%d htot=%d hfrac=%f\n",
+ vtrans, vtot, (double)vtrans/vtot, htrans, htot, (double)htrans/htot
+ );
+
+ if((double)vtrans/vtot > (double)htrans/htot){
+ DBG (10, "sanei_magic_findTurn: suggest turning 90\n");
+ *angle = 90;
+ }
+
+ cleanup:
+
+ DBG(10,"sanei_magic_findTurn: finish\n");
+
+ return ret;
+}
+
+/* FIXME: Do in-place rotation to save memory */
+SANE_Status
+sanei_magic_turn(SANE_Parameters * params, SANE_Byte * buffer,
+ int angle)
+{
+ SANE_Status ret = SANE_STATUS_GOOD;
+ int opwidth, ipwidth = params->pixels_per_line;
+ int obwidth, ibwidth = params->bytes_per_line;
+ int oheight, iheight = params->lines;
+ int depth = 1;
+
+ unsigned char * outbuf = NULL;
+ int i, j, k;
+
+ DBG(10,"sanei_magic_turn: start %d\n",angle);
+
+ if(params->format == SANE_FRAME_RGB)
+ depth = 3;
+
+ /*clean angle and convert to 0-3*/
+ angle = (angle % 360) / 90;
+
+ /*figure size of output image*/
+ switch(angle){
+ case 1:
+ case 3:
+ opwidth = iheight;
+ oheight = ipwidth;
+
+ /*gray and color, 1 or 3 bytes per pixel*/
+ if ( params->format == SANE_FRAME_RGB
+ || (params->format == SANE_FRAME_GRAY && params->depth == 8)
+ ){
+ obwidth = opwidth*depth;
+ }
+
+ /*clamp binary to byte width. must be <= input image*/
+ else if(params->format == SANE_FRAME_GRAY && params->depth == 1){
+ obwidth = opwidth/8;
+ opwidth = obwidth*8;
+ }
+
+ else{
+ DBG(10,"sanei_magic_turn: bad params\n");
+ ret = SANE_STATUS_INVAL;
+ goto cleanup;
+ }
+
+ break;
+
+ case 2:
+ opwidth = ipwidth;
+ obwidth = ibwidth;
+ oheight = iheight;
+ break;
+
+ default:
+ DBG(10,"sanei_magic_turn: no turn\n");
+ goto cleanup;
+ }
+
+ /*get output image buffer*/
+ outbuf = malloc(obwidth*oheight);
+ if(!outbuf){
+ DBG(15,"sanei_magic_turn: no outbuf\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ /*turn color & gray image*/
+ if(params->format == SANE_FRAME_RGB ||
+ (params->format == SANE_FRAME_GRAY && params->depth == 8)
+ ){
+
+ switch (angle) {
+
+ /*rotate 90 clockwise*/
+ case 1:
+ for (i=0; i<oheight; i++) {
+ for (j=0; j<opwidth; j++) {
+ for (k=0; k<depth; k++) {
+ outbuf[i*obwidth + j*depth + k]
+ = buffer[(iheight-j-1)*ibwidth + i*depth + k];
+ }
+ }
+ }
+ break;
+
+ /*rotate 180 clockwise*/
+ case 2:
+ for (i=0; i<oheight; i++) {
+ for (j=0; j<opwidth; j++) {
+ for (k=0; k<depth; k++) {
+ outbuf[i*obwidth + j*depth + k]
+ = buffer[(iheight-i-1)*ibwidth + (ipwidth-j-1)*depth + k];
+ }
+ }
+ }
+ break;
+
+ /*rotate 270 clockwise*/
+ case 3:
+ for (i=0; i<oheight; i++) {
+ for (j=0; j<opwidth; j++) {
+ for (k=0; k<depth; k++) {
+ outbuf[i*obwidth + j*depth + k]
+ = buffer[j*ibwidth + (ipwidth-i-1)*depth + k];
+ }
+ }
+ }
+ break;
+ } /*end switch*/
+ }
+
+ /*turn binary image*/
+ else if(params->format == SANE_FRAME_GRAY && params->depth == 1){
+
+ switch (angle) {
+
+ /*rotate 90 clockwise*/
+ case 1:
+ for (i=0; i<oheight; i++) {
+ for (j=0; j<opwidth; j++) {
+ unsigned char curr
+ = buffer[(iheight-j-1)*ibwidth + i/8] >> (7-(i%8)) & 1;
+
+ unsigned char mask = 1 << (7-(j%8));
+
+ if(curr){
+ outbuf[i*obwidth + j/8] |= mask;
+ }
+ else{
+ outbuf[i*obwidth + j/8] &= (~mask);
+ }
+
+ }
+ }
+ break;
+
+ /*rotate 180 clockwise*/
+ case 2:
+ for (i=0; i<oheight; i++) {
+ for (j=0; j<opwidth; j++) {
+ unsigned char curr
+ = buffer[(iheight-i-1)*ibwidth + (ipwidth-j-1)/8] >> (j%8) & 1;
+
+ unsigned char mask = 1 << (7-(j%8));
+
+ if(curr){
+ outbuf[i*obwidth + j/8] |= mask;
+ }
+ else{
+ outbuf[i*obwidth + j/8] &= (~mask);
+ }
+
+ }
+ }
+ break;
+
+ /*rotate 270 clockwise*/
+ case 3:
+ for (i=0; i<oheight; i++) {
+ for (j=0; j<opwidth; j++) {
+ unsigned char curr
+ = buffer[j*ibwidth + (ipwidth-i-1)/8] >> (i%8) & 1;
+
+ unsigned char mask = 1 << (7-(j%8));
+
+ if(curr){
+ outbuf[i*obwidth + j/8] |= mask;
+ }
+ else{
+ outbuf[i*obwidth + j/8] &= (~mask);
+ }
+
+ }
+ }
+ break;
+ } /*end switch*/
+ }
+
+ else{
+ DBG (5, "sanei_magic_turn: unsupported format/depth\n");
+ ret = SANE_STATUS_INVAL;
+ goto cleanup;
+ }
+
+ /*copy output back into input buffer*/
+ memcpy(buffer,outbuf,obwidth*oheight);
+
+ /*update input params*/
+ params->pixels_per_line = opwidth;
+ params->bytes_per_line = obwidth;
+ params->lines = oheight;
+
+ cleanup:
+
+ if(outbuf)
+ free(outbuf);
+
+ DBG(10,"sanei_magic_turn: finish\n");
+
+ return ret;
+}
+
+/* Utility functions, not used outside this file */
+
+/* Repeatedly call getLine to find the best range of slope and offset.
+ * Shift the ranges thru 4 different positions to avoid splitting data
+ * across multiple bins (false positive). Home-in on the most likely upper
+ * line of the paper inside the image. Return the 'best' edge. */
+static SANE_Status
+getTopEdge(int width, int height, int resolution,
+ int * buff, double * finSlope, int * finXInter, int * finYInter)
+{
+ SANE_Status ret = SANE_STATUS_GOOD;
+
+ int slopes = 31;
+ int offsets = 31;
+ double maxSlope = 1;
+ double minSlope = -1;
+ int maxOffset = resolution;
+ int minOffset = -resolution;
+
+ double topSlope = 0;
+ int topOffset = 0;
+ int topDensity = 0;
+
+ int i,j;
+ int pass = 0;
+
+ DBG(10,"getTopEdge: start\n");
+
+ while(pass++ < 7){
+ double sStep = (maxSlope-minSlope)/slopes;
+ int oStep = (maxOffset-minOffset)/offsets;
+
+ double slope = 0;
+ int offset = 0;
+ int density = 0;
+ int go = 0;
+
+ topSlope = 0;
+ topOffset = 0;
+ topDensity = 0;
+
+ /* find lines 4 times with slightly moved params,
+ * to bypass binning errors, highest density wins */
+ for(i=0;i<2;i++){
+ double sStep2 = sStep*i/2;
+ for(j=0;j<2;j++){
+ int oStep2 = oStep*j/2;
+ ret = getLine(height,width,buff,slopes,minSlope+sStep2,maxSlope+sStep2,offsets,minOffset+oStep2,maxOffset+oStep2,&slope,&offset,&density);
+ if(ret){
+ DBG(5,"getTopEdge: getLine error %d\n",ret);
+ return ret;
+ }
+ DBG(15,"getTopEdge: %d %d %+0.4f %d %d\n",i,j,slope,offset,density);
+
+ if(density > topDensity){
+ topSlope = slope;
+ topOffset = offset;
+ topDensity = density;
+ }
+ }
+ }
+
+ DBG(15,"getTopEdge: ok %+0.4f %d %d\n",topSlope,topOffset,topDensity);
+
+ /* did not find anything promising on first pass,
+ * give up instead of fixating on some small, pointless feature */
+ if(pass == 1 && topDensity < width/5){
+ DBG(5,"getTopEdge: density too small %d %d\n",topDensity,width);
+ topOffset = 0;
+ topSlope = 0;
+ break;
+ }
+
+ /* if slope can zoom in some more, do so. */
+ if(sStep >= 0.0001){
+ minSlope = topSlope - sStep;
+ maxSlope = topSlope + sStep;
+ go = 1;
+ }
+
+ /* if offset can zoom in some more, do so. */
+ if(oStep){
+ minOffset = topOffset - oStep;
+ maxOffset = topOffset + oStep;
+ go = 1;
+ }
+
+ /* cannot zoom in more, bail out */
+ if(!go){
+ break;
+ }
+
+ DBG(15,"getTopEdge: zoom: %+0.4f %+0.4f %d %d\n",
+ minSlope,maxSlope,minOffset,maxOffset);
+ }
+
+ /* topOffset is in the center of the image,
+ * convert to x and y intercept */
+ if(topSlope != 0){
+ *finYInter = topOffset - topSlope * width/2;
+ *finXInter = *finYInter / -topSlope;
+ *finSlope = topSlope;
+ }
+ else{
+ *finYInter = 0;
+ *finXInter = 0;
+ *finSlope = 0;
+ }
+
+ DBG(10,"getTopEdge: finish\n");
+
+ return 0;
+}
+
+/* Loop thru a transition array, and use a simplified Hough transform
+ * to divide likely edges into a 2-d array of bins. Then weight each
+ * bin based on its angle and offset. Return the 'best' bin. */
+static SANE_Status
+getLine (int height, int width, int * buff,
+ int slopes, double minSlope, double maxSlope,
+ int offsets, int minOffset, int maxOffset,
+ double * finSlope, int * finOffset, int * finDensity)
+{
+ SANE_Status ret = 0;
+
+ int ** lines = NULL;
+ int i, j;
+ int rise, run;
+ double slope;
+ int offset;
+ int sIndex, oIndex;
+ int hWidth = width/2;
+
+ double * slopeCenter = NULL;
+ int * slopeScale = NULL;
+ double * offsetCenter = NULL;
+ int * offsetScale = NULL;
+
+ int maxDensity = 1;
+ double absMaxSlope = fabs(maxSlope);
+ double absMinSlope = fabs(minSlope);
+ int absMaxOffset = abs(maxOffset);
+ int absMinOffset = abs(minOffset);
+
+ DBG(10,"getLine: start %+0.4f %+0.4f %d %d\n",
+ minSlope,maxSlope,minOffset,maxOffset);
+
+ /*silence compiler*/
+ height = height;
+
+ if(absMaxSlope < absMinSlope)
+ absMaxSlope = absMinSlope;
+
+ if(absMaxOffset < absMinOffset)
+ absMaxOffset = absMinOffset;
+
+ /* build an array of pretty-print values for slope */
+ slopeCenter = calloc(slopes,sizeof(double));
+ if(!slopeCenter){
+ DBG(5,"getLine: cant load slopeCenter\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ /* build an array of scaling factors for slope */
+ slopeScale = calloc(slopes,sizeof(int));
+ if(!slopeScale){
+ DBG(5,"getLine: cant load slopeScale\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ for(j=0;j<slopes;j++){
+
+ /* find central value of this 'bucket' */
+ slopeCenter[j] = (
+ (double)j*(maxSlope-minSlope)/slopes+minSlope
+ + (double)(j+1)*(maxSlope-minSlope)/slopes+minSlope
+ )/2;
+
+ /* scale value from the requested range into an inverted 100-1 range
+ * input close to 0 makes output close to 100 */
+ slopeScale[j] = 101 - fabs(slopeCenter[j])*100/absMaxSlope;
+ }
+
+ /* build an array of pretty-print values for offset */
+ offsetCenter = calloc(offsets,sizeof(double));
+ if(!offsetCenter){
+ DBG(5,"getLine: cant load offsetCenter\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ /* build an array of scaling factors for offset */
+ offsetScale = calloc(offsets,sizeof(int));
+ if(!offsetScale){
+ DBG(5,"getLine: cant load offsetScale\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ for(j=0;j<offsets;j++){
+
+ /* find central value of this 'bucket'*/
+ offsetCenter[j] = (
+ (double)j/offsets*(maxOffset-minOffset)+minOffset
+ + (double)(j+1)/offsets*(maxOffset-minOffset)+minOffset
+ )/2;
+
+ /* scale value from the requested range into an inverted 100-1 range
+ * input close to 0 makes output close to 100 */
+ offsetScale[j] = 101 - fabs(offsetCenter[j])*100/absMaxOffset;
+ }
+
+ /* build 2-d array of 'density', divided into slope and offset ranges */
+ lines = calloc(slopes, sizeof(int *));
+ if(!lines){
+ DBG(5,"getLine: cant load lines\n");
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+
+ for(i=0;i<slopes;i++){
+ if(!(lines[i] = calloc(offsets, sizeof(int)))){
+ DBG(5,"getLine: cant load lines %d\n",i);
+ ret = SANE_STATUS_NO_MEM;
+ goto cleanup;
+ }
+ }
+
+ for(i=0;i<width;i++){
+ for(j=i+1;j<width && j<i+width/3;j++){
+
+ /*FIXME: check for invalid (min/max) values?*/
+ rise = buff[j] - buff[i];
+ run = j-i;
+
+ slope = (double)rise/run;
+ if(slope >= maxSlope || slope < minSlope)
+ continue;
+
+ /* offset in center of width, not y intercept! */
+ offset = slope * hWidth + buff[i] - slope * i;
+ if(offset >= maxOffset || offset < minOffset)
+ continue;
+
+ sIndex = (slope - minSlope) * slopes/(maxSlope-minSlope);
+ if(sIndex >= slopes)
+ continue;
+
+ oIndex = (offset - minOffset) * offsets/(maxOffset-minOffset);
+ if(oIndex >= offsets)
+ continue;
+
+ lines[sIndex][oIndex]++;
+ }
+ }
+
+ /* go thru array, and find most dense line (highest number) */
+ for(i=0;i<slopes;i++){
+ for(j=0;j<offsets;j++){
+ if(lines[i][j] > maxDensity)
+ maxDensity = lines[i][j];
+ }
+ }
+
+ DBG(15,"getLine: maxDensity %d\n",maxDensity);
+
+ *finSlope = 0;
+ *finOffset = 0;
+ *finDensity = 0;
+
+ /* go thru array, and scale densities to % of maximum, plus adjust for
+ * prefered (smaller absolute value) slope and offset */
+ for(i=0;i<slopes;i++){
+ for(j=0;j<offsets;j++){
+ lines[i][j] = (float)lines[i][j] / maxDensity * slopeScale[i] * offsetScale[j];
+ if(lines[i][j] > *finDensity){
+ *finDensity = lines[i][j];
+ *finSlope = slopeCenter[i];
+ *finOffset = offsetCenter[j];
+ }
+ }
+ }
+
+ if(0){
+ fprintf(stderr,"offsetCenter: ");
+ for(j=0;j<offsets;j++){
+ fprintf(stderr," %+04.0f",offsetCenter[j]);
+ }
+ fprintf(stderr,"\n");
+
+ fprintf(stderr,"offsetScale: ");
+ for(j=0;j<offsets;j++){
+ fprintf(stderr," %04d",offsetScale[j]);
+ }
+ fprintf(stderr,"\n");
+
+ for(i=0;i<slopes;i++){
+ fprintf(stderr,"slope: %02d %+02.2f %03d:",i,slopeCenter[i],slopeScale[i]);
+ for(j=0;j<offsets;j++){
+ fprintf(stderr,"% 5d",lines[i][j]);
+ }
+ fprintf(stderr,"\n");
+ }
+ }
+
+ /* dont forget to cleanup */
+ cleanup:
+ for(i=0;i<slopes;i++){
+ if(lines[i])
+ free(lines[i]);
+ }
+ if(lines)
+ free(lines);
+ if(slopeCenter)
+ free(slopeCenter);
+ if(slopeScale)
+ free(slopeScale);
+ if(offsetCenter)
+ free(offsetCenter);
+ if(offsetScale)
+ free(offsetScale);
+
+ DBG(10,"getLine: finish\n");
+
+ return ret;
+}
+
+/* find the left side of paper by moving a line
+ * perpendicular to top slope across the image
+ * the 'left-most' point on the paper is the
+ * one with the smallest X intercept
+ * return x and y intercepts */
+static SANE_Status
+getLeftEdge (int width, int height, int * top, int * bot,
+ double slope, int * finXInter, int * finYInter)
+{
+
+ int i;
+ int topXInter, topYInter;
+ int botXInter, botYInter;
+ int leftCount;
+
+ DBG(10,"getEdgeSlope: start\n");
+
+ topXInter = width;
+ topYInter = 0;
+ leftCount = 0;
+
+ for(i=0;i<width;i++){
+
+ if(top[i] < height){
+ int tyi = top[i] - (slope * i);
+ int txi = tyi/-slope;
+
+ if(topXInter > txi){
+ topXInter = txi;
+ topYInter = tyi;
+ }
+
+ leftCount++;
+ if(leftCount > 5){
+ break;
+ }
+ }
+ else{
+ topXInter = width;
+ topYInter = 0;
+ leftCount = 0;
+ }
+ }
+
+ botXInter = width;
+ botYInter = 0;
+ leftCount = 0;
+
+ for(i=0;i<width;i++){
+
+ if(bot[i] > -1){
+
+ int byi = bot[i] - (slope * i);
+ int bxi = byi/-slope;
+
+ if(botXInter > bxi){
+ botXInter = bxi;
+ botYInter = byi;
+ }
+
+ leftCount++;
+ if(leftCount > 5){
+ break;
+ }
+ }
+ else{
+ botXInter = width;
+ botYInter = 0;
+ leftCount = 0;
+ }
+ }
+
+ if(botXInter < topXInter){
+ *finXInter = botXInter;
+ *finYInter = botYInter;
+ }
+ else{
+ *finXInter = topXInter;
+ *finYInter = topYInter;
+ }
+
+ DBG(10,"getEdgeSlope: finish\n");
+
+ return 0;
+}
+
+/* Loop thru the image and look for first color change in each column.
+ * Return a malloc'd array. Caller is responsible for freeing. */
+int *
+sanei_magic_getTransY (
+ SANE_Parameters * params, int dpi, SANE_Byte * buffer, int top)
+{
+ int * buff;
+
+ int i, j, k;
+ int winLen = 9;
+
+ int width = params->pixels_per_line;
+ int height = params->lines;
+ int depth = 1;
+
+ /* defaults for bottom-up */
+ int firstLine = height-1;
+ int lastLine = -1;
+ int direction = -1;
+
+ DBG (10, "sanei_magic_getTransY: start\n");
+
+ /* override for top-down */
+ if(top){
+ firstLine = 0;
+ lastLine = height;
+ direction = 1;
+ }
+
+ /* build output and preload with impossible value */
+ buff = calloc(width,sizeof(int));
+ if(!buff){
+ DBG (5, "sanei_magic_getTransY: no buff\n");
+ return NULL;
+ }
+ for(i=0; i<width; i++)
+ buff[i] = lastLine;
+
+ /* load the buff array with y value for first color change from edge
+ * gray/color uses a different algo from binary/halftone */
+ if(params->format == SANE_FRAME_RGB ||
+ (params->format == SANE_FRAME_GRAY && params->depth == 8)
+ ){
+
+ if(params->format == SANE_FRAME_RGB)
+ depth = 3;
+
+ /* loop over all columns, find first transition */
+ for(i=0; i<width; i++){
+
+ int near = 0;
+ int far = 0;
+
+ /* load the near and far windows with repeated copy of first pixel */
+ for(k=0; k<depth; k++){
+ near += buffer[(firstLine*width+i) * depth + k];
+ }
+ near *= winLen;
+ far = near;
+
+ /* move windows, check delta */
+ for(j=firstLine+direction; j!=lastLine; j+=direction){
+
+ int farLine = j-winLen*2*direction;
+ int nearLine = j-winLen*direction;
+
+ if(farLine < 0 || farLine >= height){
+ farLine = firstLine;
+ }
+ if(nearLine < 0 || nearLine >= height){
+ nearLine = firstLine;
+ }
+
+ for(k=0; k<depth; k++){
+ far -= buffer[(farLine*width+i)*depth+k];
+ far += buffer[(nearLine*width+i)*depth+k];
+
+ near -= buffer[(nearLine*width+i)*depth+k];
+ near += buffer[(j*width+i)*depth+k];
+ }
+
+ /* significant transition */
+ if(abs(near - far) > 50*winLen*depth - near*40/255){
+ buff[i] = j;
+ break;
+ }
+ }
+ }
+ }
+
+ else if(params->format == SANE_FRAME_GRAY && params->depth == 1){
+
+ int near = 0;
+
+ for(i=0; i<width; i++){
+
+ /* load the near window with first pixel */
+ near = buffer[(firstLine*width+i)/8] >> (7-(i%8)) & 1;
+
+ /* move */
+ for(j=firstLine+direction; j!=lastLine; j+=direction){
+ if((buffer[(j*width+i)/8] >> (7-(i%8)) & 1) != near){
+ buff[i] = j;
+ break;
+ }
+ }
+ }
+ }
+
+ /* some other format? */
+ else{
+ DBG (5, "sanei_magic_getTransY: unsupported format/depth\n");
+ free(buff);
+ return NULL;
+ }
+
+ /* ignore transitions with few neighbors within .5 inch */
+ for(i=0;i<width-7;i++){
+ int sum = 0;
+ for(j=1;j<=7;j++){
+ if(abs(buff[i+j] - buff[i]) < dpi/2)
+ sum++;
+ }
+ if(sum < 2)
+ buff[i] = lastLine;
+ }
+
+ DBG (10, "sanei_magic_getTransY: finish\n");
+
+ return buff;
+}
+
+/* Loop thru the image height and look for first color change in each row.
+ * Return a malloc'd array. Caller is responsible for freeing. */
+int *
+sanei_magic_getTransX (
+ SANE_Parameters * params, int dpi, SANE_Byte * buffer, int left)
+{
+ int * buff;
+
+ int i, j, k;
+ int winLen = 9;
+
+ int bwidth = params->bytes_per_line;
+ int width = params->pixels_per_line;
+ int height = params->lines;
+ int depth = 1;
+
+ /* defaults for right-first */
+ int firstCol = width-1;
+ int lastCol = -1;
+ int direction = -1;
+
+ DBG (10, "sanei_magic_getTransX: start\n");
+
+ /* override for left-first*/
+ if(left){
+ firstCol = 0;
+ lastCol = width;
+ direction = 1;
+ }
+
+ /* build output and preload with impossible value */
+ buff = calloc(height,sizeof(int));
+ if(!buff){
+ DBG (5, "sanei_magic_getTransX: no buff\n");
+ return NULL;
+ }
+ for(i=0; i<height; i++)
+ buff[i] = lastCol;
+
+ /* load the buff array with x value for first color change from edge
+ * gray/color uses a different algo from binary/halftone */
+ if(params->format == SANE_FRAME_RGB ||
+ (params->format == SANE_FRAME_GRAY && params->depth == 8)
+ ){
+
+ if(params->format == SANE_FRAME_RGB)
+ depth = 3;
+
+ /* loop over all columns, find first transition */
+ for(i=0; i<height; i++){
+
+ int near = 0;
+ int far = 0;
+
+ /* load the near and far windows with repeated copy of first pixel */
+ for(k=0; k<depth; k++){
+ near += buffer[i*bwidth + k];
+ }
+ near *= winLen;
+ far = near;
+
+ /* move windows, check delta */
+ for(j=firstCol+direction; j!=lastCol; j+=direction){
+
+ int farCol = j-winLen*2*direction;
+ int nearCol = j-winLen*direction;
+
+ if(farCol < 0 || farCol >= width){
+ farCol = firstCol;
+ }
+ if(nearCol < 0 || nearCol >= width){
+ nearCol = firstCol;
+ }
+
+ for(k=0; k<depth; k++){
+ far -= buffer[i*bwidth + farCol*depth + k];
+ far += buffer[i*bwidth + nearCol*depth + k];
+
+ near -= buffer[i*bwidth + nearCol*depth + k];
+ near += buffer[i*bwidth + j*depth + k];
+ }
+
+ if(abs(near - far) > 50*winLen*depth - near*40/255){
+ buff[i] = j;
+ break;
+ }
+ }
+ }
+ }
+
+ else if (params->format == SANE_FRAME_GRAY && params->depth == 1){
+
+ int near = 0;
+
+ for(i=0; i<height; i++){
+
+ /* load the near window with first pixel */
+ near = buffer[i*bwidth + firstCol/8] >> (7-(firstCol%8)) & 1;
+
+ /* move */
+ for(j=firstCol+direction; j!=lastCol; j+=direction){
+ if((buffer[i*bwidth + j/8] >> (7-(j%8)) & 1) != near){
+ buff[i] = j;
+ break;
+ }
+ }
+ }
+ }
+
+ /* some other format? */
+ else{
+ DBG (5, "sanei_magic_getTransX: unsupported format/depth\n");
+ free(buff);
+ return NULL;
+ }
+
+ /* ignore transitions with few neighbors within .5 inch */
+ for(i=0;i<height-7;i++){
+ int sum = 0;
+ for(j=1;j<=7;j++){
+ if(abs(buff[i+j] - buff[i]) < dpi/2)
+ sum++;
+ }
+ if(sum < 2)
+ buff[i] = lastCol;
+ }
+
+ DBG (10, "sanei_magic_getTransX: finish\n");
+
+ return buff;
+}
+