// Helper subtracts the line_pix image from the src_pix, and removes residue
// as well by removing components that touch the line, but are not in the
// non_line_pix mask. It is assumed that the non_line_pix mask has already
// been prepared to required accuracy.
static void SubtractLinesAndResidue(Pix* line_pix, Pix* non_line_pix,
int resolution, Pix* src_pix) {
// First remove the lines themselves.
pixSubtract(src_pix, src_pix, line_pix);
// Subtract the non-lines from the image to get the residue.
Pix* residue_pix = pixSubtract(NULL, src_pix, non_line_pix);
// Dilate the lines so they touch the residue.
Pix* fat_line_pix = pixDilateBrick(NULL, line_pix, 3, 3);
// Seed fill the fat lines to get all the residue.
pixSeedfillBinary(fat_line_pix, fat_line_pix, residue_pix, 8);
// Subtract the residue from the original image.
pixSubtract(src_pix, src_pix, fat_line_pix);
pixDestroy(&fat_line_pix);
pixDestroy(&residue_pix);
}
// Get a set of bounding boxes of possible vertical lines in the image.
// The input resolution overrides any resolution set in src_pix.
// The output line_pix contains just all the detected lines.
Boxa* LineFinder::GetVLineBoxes(int resolution, Pix* src_pix, Pix** line_pix) {
#ifdef HAVE_LIBLEPT
// Remove any parts of 1 inch/kThinLineFraction wide or more, by opening
// away the thin lines and subtracting what's left.
// This is very generous and will leave in even quite wide lines.
Pix* pixt1 = pixOpenBrick(NULL, src_pix, resolution / kThinLineFraction, 1);
pixSubtract(pixt1, src_pix, pixt1);
// Spread sideways to allow for some skew.
Pix* pixt2 = pixDilateBrick(NULL, pixt1, 3, 1);
// Now keep only tall stuff of height at least 1 inch/kMinLineLengthFraction.
pixOpenBrick(pixt1, pixt2, 1, resolution / kMinLineLengthFraction);
pixDestroy(&pixt2);
// Put a single pixel crack in every line at an arbitrary spacing,
// so they break up and the bounding boxes can be used to get the
// direction accurately enough without needing outlines.
int wpl = pixGetWpl(pixt1);
int height = pixGetHeight(pixt1);
l_uint32* data = pixGetData(pixt1);
for (int y = kCrackSpacing; y < height; y += kCrackSpacing) {
memset(data + wpl * y, 0, wpl * sizeof(*data));
}
if (textord_tabfind_show_vlines)
pixWrite("vlines.png", pixt1, IFF_PNG);
Boxa* boxa = pixConnComp(pixt1, NULL, 8);
*line_pix = pixt1;
return boxa;
#else
return NULL;
#endif
}
/*!
* pixGenHalftoneMask()
*
* Input: pixs (1 bpp, assumed to be 150 to 200 ppi)
* &pixtext (<optional return> text part of pixs)
* &htfound (<optional return> 1 if the mask is not empty)
* debug (flag: 1 for debug output)
* Return: pixd (halftone mask), or null on error
*/
PIX *
pixGenHalftoneMask(PIX *pixs,
PIX **ppixtext,
l_int32 *phtfound,
l_int32 debug)
{
l_int32 empty;
PIX *pixt1, *pixt2, *pixhs, *pixhm, *pixd;
PROCNAME("pixGenHalftoneMask");
if (ppixtext) *ppixtext = NULL;
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (pixGetDepth(pixs) != 1)
return (PIX *)ERROR_PTR("pixs not 1 bpp", procName, NULL);
/* Compute seed for halftone parts at 8x reduction */
pixt1 = pixReduceRankBinaryCascade(pixs, 4, 4, 3, 0);
pixt2 = pixOpenBrick(NULL, pixt1, 5, 5);
pixhs = pixExpandReplicate(pixt2, 8); /* back to 2x reduction */
pixDestroy(&pixt1);
pixDestroy(&pixt2);
pixDisplayWriteFormat(pixhs, debug, IFF_PNG);
/* Compute mask for connected regions */
pixhm = pixCloseSafeBrick(NULL, pixs, 4, 4);
pixDisplayWriteFormat(pixhm, debug, IFF_PNG);
/* Fill seed into mask to get halftone mask */
pixd = pixSeedfillBinary(NULL, pixhs, pixhm, 4);
#if 0
/* Moderate opening to remove thin lines, etc. */
pixOpenBrick(pixd, pixd, 10, 10);
pixDisplayWrite(pixd, debug);
#endif
/* Check if mask is empty */
pixZero(pixd, &empty);
if (phtfound) {
*phtfound = 0;
if (!empty)
*phtfound = 1;
}
/* Optionally, get all pixels that are not under the halftone mask */
if (ppixtext) {
if (empty)
*ppixtext = pixCopy(NULL, pixs);
else
*ppixtext = pixSubtract(NULL, pixs, pixd);
pixDisplayWriteFormat(*ppixtext, debug, IFF_PNG);
}
pixDestroy(&pixhs);
pixDestroy(&pixhm);
return pixd;
}
// Finds horizontal line objects in the given pix.
// Uses the given resolution to determine size thresholds instead of any
// that may be present in the pix.
// The output vectors are owned by the list and Frozen (cannot refit) by
// having no boxes, as there is no need to refit or merge separator lines.
void LineFinder::FindHorizontalLines(int resolution, Pix* pix,
TabVector_LIST* vectors) {
#ifdef HAVE_LIBLEPT
Pix* line_pix;
Boxa* boxes = GetHLineBoxes(resolution, pix, &line_pix);
C_BLOB_LIST line_cblobs;
int width = pixGetWidth(pix);
int height = pixGetHeight(pix);
ConvertBoxaToBlobs(height, width, &boxes, &line_cblobs);
// Make the BLOBNBOXes from the C_BLOBs.
BLOBNBOX_LIST line_bblobs;
C_BLOB_IT blob_it(&line_cblobs);
BLOBNBOX_IT bbox_it(&line_bblobs);
for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
C_BLOB* cblob = blob_it.data();
BLOBNBOX* bblob = new BLOBNBOX(cblob);
bbox_it.add_to_end(bblob);
}
ICOORD bleft(0, 0);
ICOORD tright(height, width);
int vertical_x, vertical_y;
FindLineVectors(bleft, tright, &line_bblobs, &vertical_x, &vertical_y,
vectors);
if (!vectors->empty()) {
// Some lines were found, so erase the unused blobs from the line image
// and then subtract the line image from the source.
bbox_it.move_to_first();
for (bbox_it.mark_cycle_pt(); !bbox_it.cycled_list(); bbox_it.forward()) {
BLOBNBOX* blob = bbox_it.data();
if (blob->left_tab_type() == TT_UNCONFIRMED) {
const TBOX& box = blob->bounding_box();
// Coords are in tess format so filp x and y and then covert
// to leptonica by height -y.
Box* pixbox = boxCreate(box.bottom(), height - box.right(),
box.height(), box.width());
pixClearInRect(line_pix, pixbox);
boxDestroy(&pixbox);
}
}
pixDilateBrick(line_pix, line_pix, 3, 1);
pixSubtract(pix, pix, line_pix);
if (textord_tabfind_show_vlines)
pixWrite("hlinesclean.png", line_pix, IFF_PNG);
ICOORD vertical;
vertical.set_with_shrink(vertical_x, vertical_y);
TabVector::MergeSimilarTabVectors(vertical, vectors, NULL);
// Iterate the vectors to flip them.
TabVector_IT h_it(vectors);
for (h_it.mark_cycle_pt(); !h_it.cycled_list(); h_it.forward()) {
h_it.data()->XYFlip();
}
}
pixDestroy(&line_pix);
#endif
}
// Finds vertical line objects in the given pix.
// Uses the given resolution to determine size thresholds instead of any
// that may be present in the pix.
// The output vertical_x and vertical_y contain a sum of the output vectors,
// thereby giving the mean vertical direction.
// The output vectors are owned by the list and Frozen (cannot refit) by
// having no boxes, as there is no need to refit or merge separator lines.
void LineFinder::FindVerticalLines(int resolution, Pix* pix,
int* vertical_x, int* vertical_y,
TabVector_LIST* vectors) {
#ifdef HAVE_LIBLEPT
Pix* line_pix;
Boxa* boxes = GetVLineBoxes(resolution, pix, &line_pix);
C_BLOB_LIST line_cblobs;
int width = pixGetWidth(pix);
int height = pixGetHeight(pix);
ConvertBoxaToBlobs(width, height, &boxes, &line_cblobs);
// Make the BLOBNBOXes from the C_BLOBs.
BLOBNBOX_LIST line_bblobs;
C_BLOB_IT blob_it(&line_cblobs);
BLOBNBOX_IT bbox_it(&line_bblobs);
for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
C_BLOB* cblob = blob_it.data();
BLOBNBOX* bblob = new BLOBNBOX(cblob);
bbox_it.add_to_end(bblob);
}
ICOORD bleft(0, 0);
ICOORD tright(width, height);
FindLineVectors(bleft, tright, &line_bblobs, vertical_x, vertical_y, vectors);
if (!vectors->empty()) {
// Some lines were found, so erase the unused blobs from the line image
// and then subtract the line image from the source.
bbox_it.move_to_first();
for (bbox_it.mark_cycle_pt(); !bbox_it.cycled_list(); bbox_it.forward()) {
BLOBNBOX* blob = bbox_it.data();
if (blob->left_tab_type() == TT_UNCONFIRMED) {
const TBOX& box = blob->bounding_box();
Box* pixbox = boxCreate(box.left(), height - box.top(),
box.width(), box.height());
pixClearInRect(line_pix, pixbox);
boxDestroy(&pixbox);
}
}
pixDilateBrick(line_pix, line_pix, 1, 3);
pixSubtract(pix, pix, line_pix);
if (textord_tabfind_show_vlines)
pixWrite("vlinesclean.png", line_pix, IFF_PNG);
ICOORD vertical;
vertical.set_with_shrink(*vertical_x, *vertical_y);
TabVector::MergeSimilarTabVectors(vertical, vectors, NULL);
}
pixDestroy(&line_pix);
#endif
}
// Get a set of bounding boxes of possible horizontal lines in the image.
// The input resolution overrides any resolution set in src_pix.
// The output line_pix contains just all the detected lines.
// The output boxes undergo the transformation (x,y)->(height-y,x) so the
// lines can be found with a vertical line finder afterwards.
// This transformation allows a simple x/y flip to reverse it in tesseract
// coordinates and it is faster to flip the lines than rotate the image.
Boxa* LineFinder::GetHLineBoxes(int resolution, Pix* src_pix, Pix** line_pix) {
#ifdef HAVE_LIBLEPT
// Remove any parts of 1 inch/kThinLineFraction high or more, by opening
// away the thin lines and subtracting what's left.
// This is very generous and will leave in even quite wide lines.
Pix* pixt1 = pixOpenBrick(NULL, src_pix, 1, resolution / kThinLineFraction);
pixSubtract(pixt1, src_pix, pixt1);
// Spread vertically to allow for some skew.
Pix* pixt2 = pixDilateBrick(NULL, pixt1, 1, 3);
// Now keep only wide stuff of width at least 1 inch/kMinLineLengthFraction.
pixOpenBrick(pixt1, pixt2, resolution / kMinLineLengthFraction, 1);
pixDestroy(&pixt2);
// Put a single pixel crack in every line at an arbitrary spacing,
// so they break up and the bounding boxes can be used to get the
// direction accurately enough without needing outlines.
int wpl = pixGetWpl(pixt1);
int width = pixGetWidth(pixt1);
int height = pixGetHeight(pixt1);
l_uint32* data = pixGetData(pixt1);
for (int y = 0; y < height; ++y, data += wpl) {
for (int x = kCrackSpacing; x < width; x += kCrackSpacing) {
CLEAR_DATA_BIT(data, x);
}
}
if (textord_tabfind_show_vlines)
pixWrite("hlines.png", pixt1, IFF_PNG);
Boxa* boxa = pixConnComp(pixt1, NULL, 8);
*line_pix = pixt1;
// Iterate the boxes to flip x and y.
int nboxes = boxaGetCount(boxa);
for (int i = 0; i < nboxes; ++i) {
l_int32 x, y, box_width, box_height;
boxaGetBoxGeometry(boxa, i, &x, &y, &box_width, &box_height);
Box* box = boxCreate(height - (y + box_height),
width - (x + box_width), box_height, box_width);
boxaReplaceBox(boxa, i, box);
}
return boxa;
#else
return NULL;
#endif
}
/*!
* pixGenTextblockMask()
*
* Input: pixs (1 bpp, textline mask, assumed to be 150 to 200 ppi)
* pixvws (vertical white space mask)
* debug (flag: 1 for debug output)
* Return: pixd (textblock mask), or null on error
*
* Notes:
* (1) Both the input masks (textline and vertical white space) and
* the returned textblock mask are at the same resolution.
* (2) The result is somewhat noisy, in that small "blocks" of
* text may be included. These can be removed by post-processing,
* using, e.g.,
* pixSelectBySize(pix, 60, 60, 4, L_SELECT_IF_EITHER,
* L_SELECT_IF_GTE, NULL);
*/
PIX *
pixGenTextblockMask(PIX *pixs,
PIX *pixvws,
l_int32 debug)
{
PIX *pixt1, *pixt2, *pixt3, *pixd;
PROCNAME("pixGenTextblockMask");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (!pixvws)
return (PIX *)ERROR_PTR("pixvws not defined", procName, NULL);
if (pixGetDepth(pixs) != 1)
return (PIX *)ERROR_PTR("pixs not 1 bpp", procName, NULL);
/* Join pixels vertically to make a textblock mask */
pixt1 = pixMorphSequence(pixs, "c1.10 + o4.1", 0);
pixDisplayWriteFormat(pixt1, debug, IFF_PNG);
/* Solidify the textblock mask and remove noise:
* (1) For each cc, close the blocks and dilate slightly
* to form a solid mask.
* (2) Small horizontal closing between components.
* (3) Open the white space between columns, again.
* (4) Remove small components. */
pixt2 = pixMorphSequenceByComponent(pixt1, "c30.30 + d3.3", 8, 0, 0, NULL);
pixCloseSafeBrick(pixt2, pixt2, 10, 1);
pixDisplayWriteFormat(pixt2, debug, IFF_PNG);
pixt3 = pixSubtract(NULL, pixt2, pixvws);
pixDisplayWriteFormat(pixt3, debug, IFF_PNG);
pixd = pixSelectBySize(pixt3, 25, 5, 8, L_SELECT_IF_BOTH,
L_SELECT_IF_GTE, NULL);
pixDisplayWriteFormat(pixd, debug, IFF_PNG);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
pixDestroy(&pixt3);
return pixd;
}
/*!
* pixThinGeneral()
*
* Input: pixs (1 bpp)
* type (L_THIN_FG, L_THIN_BG)
* sela (of Sels for parallel composite HMTs)
* maxiters (max number of iters allowed; use 0 to iterate
* until completion)
* Return: pixd, or null on error
*
* Notes:
* (1) See notes in pixThin(). That function chooses among
* the best of the Sels for thinning.
* (2) This is a general function that takes a Sela of HMTs
* that are used in parallel for thinning from each
* of four directions. One iteration consists of four
* such parallel thins.
*/
PIX *
pixThinGeneral(PIX *pixs,
l_int32 type,
SELA *sela,
l_int32 maxiters)
{
l_int32 i, j, r, nsels, same;
PIXA *pixahmt;
PIX **pixhmt; /* array owned by pixahmt; do not destroy! */
PIX *pixd, *pixt;
SEL *sel, *selr;
PROCNAME("pixThinGeneral");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (pixGetDepth(pixs) != 1)
return (PIX *)ERROR_PTR("pixs not 1 bpp", procName, NULL);
if (type != L_THIN_FG && type != L_THIN_BG)
return (PIX *)ERROR_PTR("invalid fg/bg type", procName, NULL);
if (!sela)
return (PIX *)ERROR_PTR("sela not defined", procName, NULL);
if (maxiters == 0) maxiters = 10000;
/* Set up array of temp pix to hold hmts */
nsels = selaGetCount(sela);
pixahmt = pixaCreate(nsels);
for (i = 0; i < nsels; i++) {
pixt = pixCreateTemplate(pixs);
pixaAddPix(pixahmt, pixt, L_INSERT);
}
pixhmt = pixaGetPixArray(pixahmt);
if (!pixhmt)
return (PIX *)ERROR_PTR("pixhmt array not made", procName, NULL);
#if DEBUG_SELS
pixt = selaDisplayInPix(sela, 35, 3, 15, 4);
pixDisplayWithTitle(pixt, 100, 100, "allsels", 1);
pixDestroy(&pixt);
#endif /* DEBUG_SELS */
/* Set up initial image for fg thinning */
if (type == L_THIN_FG)
pixd = pixCopy(NULL, pixs);
else /* bg thinning */
pixd = pixInvert(NULL, pixs);
/* Thin the fg, with up to maxiters iterations */
for (i = 0; i < maxiters; i++) {
pixt = pixCopy(NULL, pixd); /* test for completion */
for (r = 0; r < 4; r++) { /* over 90 degree rotations of Sels */
for (j = 0; j < nsels; j++) { /* over individual sels in sela */
sel = selaGetSel(sela, j); /* not a copy */
selr = selRotateOrth(sel, r);
pixHMT(pixhmt[j], pixd, selr);
selDestroy(&selr);
if (j > 0)
pixOr(pixhmt[0], pixhmt[0], pixhmt[j]); /* accum result */
}
pixSubtract(pixd, pixd, pixhmt[0]); /* remove result */
}
pixEqual(pixd, pixt, &same);
pixDestroy(&pixt);
if (same) {
L_INFO("%d iterations to completion\n", procName, i);
break;
}
}
if (type == L_THIN_BG)
pixInvert(pixd, pixd);
pixaDestroy(&pixahmt);
return pixd;
}
* that might be used *
* -------------------------------------------------------------------- */
#if 0
pixd = pixCreateTemplate(pixs);
pixd = pixDilate(NULL, pixs, sel);
pixd = pixErode(NULL, pixs, sel);
pixd = pixOpen(NULL, pixs, sel);
pixd = pixClose(NULL, pixs, sel);
pixDilate(pixd, pixs, sel);
pixErode(pixd, pixs, sel);
pixOpen(pixd, pixs, sel);
pixClose(pixd, pixs, sel);
pixAnd(pixd, pixd, pixs);
pixOr(pixd, pixd, pixs);
pixXor(pixd, pixd, pixs);
pixSubtract(pixd, pixd, pixs);
pixInvert(pixd, pixs);
pixd = pixAnd(NULL, pixd, pixs);
pixd = pixOr(NULL, pixd, pixs);
pixd = pixXor(NULL, pixd, pixs);
pixd = pixSubtract(NULL, pixd, pixs);
pixd = pixInvert(NULL, pixs);
pixInvert(pixs, pixs);
#endif /* 0 */
main(int argc,
char **argv)
{
char *filein, *fileout;
l_int32 thresh;
PIX *pixs, *pixg, *pixb;
PIX *pixmask4, *pixseed4, *pixsf4, *pixd4, *pixd;
static char mainName[] = "pagesegtest2";
if (argc != 4)
exit(ERROR_INT(" Syntax: pagesegtest2 filein thresh fileout",
mainName, 1));
filein = argv[1];
thresh = atoi(argv[2]);
fileout = argv[3];
/* Get a 1 bpp version of the page */
if ((pixs = pixRead(filein)) == NULL)
exit(ERROR_INT("pixs not made", mainName, 1));
if (pixGetDepth(pixs) == 32)
pixg = pixConvertRGBToGrayFast(pixs);
else
pixg = pixClone(pixs);
if (pixGetDepth(pixg) == 8)
pixb = pixThresholdToBinary(pixg, thresh);
else
pixb = pixClone(pixg);
/* Make seed and mask, and fill seed into mask */
pixseed4 = pixMorphSequence(pixb, seed_sequence, 0);
pixmask4 = pixMorphSequence(pixb, mask_sequence, 0);
pixsf4 = pixSeedfillBinary(NULL, pixseed4, pixmask4, 8);
pixd4 = pixMorphSequence(pixsf4, dilation_sequence, 0);
/* Mask at full resolution */
pixd = pixExpandBinaryPower2(pixd4, 4);
pixWrite(fileout, pixd, IFF_TIFF_G4);
/* Extract non-image parts (e.g., text) at full resolution */
pixSubtract(pixb, pixb, pixd);
pixDisplayWithTitle(pixseed4, 400, 100, "halftone seed", DFLAG);
pixDisplayWithTitle(pixmask4, 100, 100, "halftone seed mask", DFLAG);
pixDisplayWithTitle(pixd4, 700, 100, "halftone mask", DFLAG);
pixDisplayWithTitle(pixb, 1000, 100, "non-halftone", DFLAG);
#if 1
pixWrite("junkseed", pixseed4, IFF_TIFF_G4);
pixWrite("junkmask", pixmask4, IFF_TIFF_G4);
pixWrite("junkfill", pixd4, IFF_TIFF_G4);
pixWrite("junktext", pixb, IFF_TIFF_G4);
#endif
pixDestroy(&pixs);
pixDestroy(&pixg);
pixDestroy(&pixb);
pixDestroy(&pixseed4);
pixDestroy(&pixmask4);
pixDestroy(&pixsf4);
pixDestroy(&pixd4);
pixDestroy(&pixd);
exit(0);
}
/*!
* pixGetRegionsBinary()
*
* Input: pixs (1 bpp, assumed to be 300 to 400 ppi)
* &pixhm (<optional return> halftone mask)
* &pixtm (<optional return> textline mask)
* &pixtb (<optional return> textblock mask)
* debug (flag: set to 1 for debug output)
* Return: 0 if OK, 1 on error
*
* Notes:
* (1) It is best to deskew the image before segmenting.
* (2) The debug flag enables a number of outputs. These
* are included to show how to generate and save/display
* these results.
*/
l_int32
pixGetRegionsBinary(PIX *pixs,
PIX **ppixhm,
PIX **ppixtm,
PIX **ppixtb,
l_int32 debug)
{
char *tempname;
l_int32 htfound, tlfound;
PIX *pixr, *pixt1, *pixt2;
PIX *pixtext; /* text pixels only */
PIX *pixhm2; /* halftone mask; 2x reduction */
PIX *pixhm; /* halftone mask; */
PIX *pixtm2; /* textline mask; 2x reduction */
PIX *pixtm; /* textline mask */
PIX *pixvws; /* vertical white space mask */
PIX *pixtb2; /* textblock mask; 2x reduction */
PIX *pixtbf2; /* textblock mask; 2x reduction; small comps filtered */
PIX *pixtb; /* textblock mask */
PROCNAME("pixGetRegionsBinary");
if (ppixhm) *ppixhm = NULL;
if (ppixtm) *ppixtm = NULL;
if (ppixtb) *ppixtb = NULL;
if (!pixs)
return ERROR_INT("pixs not defined", procName, 1);
if (pixGetDepth(pixs) != 1)
return ERROR_INT("pixs not 1 bpp", procName, 1);
/* 2x reduce, to 150 -200 ppi */
pixr = pixReduceRankBinaryCascade(pixs, 1, 0, 0, 0);
pixDisplayWrite(pixr, debug);
/* Get the halftone mask */
pixhm2 = pixGenHalftoneMask(pixr, &pixtext, &htfound, debug);
/* Get the textline mask from the text pixels */
pixtm2 = pixGenTextlineMask(pixtext, &pixvws, &tlfound, debug);
/* Get the textblock mask from the textline mask */
pixtb2 = pixGenTextblockMask(pixtm2, pixvws, debug);
pixDestroy(&pixr);
pixDestroy(&pixtext);
pixDestroy(&pixvws);
/* Remove small components from the mask, where a small
* component is defined as one with both width and height < 60 */
pixtbf2 = pixSelectBySize(pixtb2, 60, 60, 4, L_SELECT_IF_EITHER,
L_SELECT_IF_GTE, NULL);
pixDestroy(&pixtb2);
pixDisplayWriteFormat(pixtbf2, debug, IFF_PNG);
/* Expand all masks to full resolution, and do filling or
* small dilations for better coverage. */
pixhm = pixExpandReplicate(pixhm2, 2);
pixt1 = pixSeedfillBinary(NULL, pixhm, pixs, 8);
pixOr(pixhm, pixhm, pixt1);
pixDestroy(&pixt1);
pixDisplayWriteFormat(pixhm, debug, IFF_PNG);
pixt1 = pixExpandReplicate(pixtm2, 2);
pixtm = pixDilateBrick(NULL, pixt1, 3, 3);
pixDestroy(&pixt1);
pixDisplayWriteFormat(pixtm, debug, IFF_PNG);
pixt1 = pixExpandReplicate(pixtbf2, 2);
pixtb = pixDilateBrick(NULL, pixt1, 3, 3);
pixDestroy(&pixt1);
pixDisplayWriteFormat(pixtb, debug, IFF_PNG);
pixDestroy(&pixhm2);
pixDestroy(&pixtm2);
pixDestroy(&pixtbf2);
/* Debug: identify objects that are neither text nor halftone image */
if (debug) {
pixt1 = pixSubtract(NULL, pixs, pixtm); /* remove text pixels */
pixt2 = pixSubtract(NULL, pixt1, pixhm); /* remove halftone pixels */
pixDisplayWriteFormat(pixt2, 1, IFF_PNG);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
}
/* Debug: display textline components with random colors */
if (debug) {
l_int32 w, h;
BOXA *boxa;
PIXA *pixa;
boxa = pixConnComp(pixtm, &pixa, 8);
pixGetDimensions(pixtm, &w, &h, NULL);
pixt1 = pixaDisplayRandomCmap(pixa, w, h);
pixcmapResetColor(pixGetColormap(pixt1), 0, 255, 255, 255);
pixDisplay(pixt1, 100, 100);
pixDisplayWriteFormat(pixt1, 1, IFF_PNG);
pixaDestroy(&pixa);
boxaDestroy(&boxa);
pixDestroy(&pixt1);
}
/* Debug: identify the outlines of each textblock */
if (debug) {
PIXCMAP *cmap;
PTAA *ptaa;
ptaa = pixGetOuterBordersPtaa(pixtb);
tempname = genTempFilename("/tmp", "tb_outlines.ptaa", 0, 0);
ptaaWrite(tempname, ptaa, 1);
FREE(tempname);
pixt1 = pixRenderRandomCmapPtaa(pixtb, ptaa, 1, 16, 1);
cmap = pixGetColormap(pixt1);
pixcmapResetColor(cmap, 0, 130, 130, 130);
pixDisplay(pixt1, 500, 100);
pixDisplayWriteFormat(pixt1, 1, IFF_PNG);
pixDestroy(&pixt1);
ptaaDestroy(&ptaa);
}
/* Debug: get b.b. for all mask components */
if (debug) {
BOXA *bahm, *batm, *batb;
bahm = pixConnComp(pixhm, NULL, 4);
batm = pixConnComp(pixtm, NULL, 4);
batb = pixConnComp(pixtb, NULL, 4);
tempname = genTempFilename("/tmp", "htmask.boxa", 0, 0);
boxaWrite(tempname, bahm);
FREE(tempname);
tempname = genTempFilename("/tmp", "textmask.boxa", 0, 0);
boxaWrite(tempname, batm);
FREE(tempname);
tempname = genTempFilename("/tmp", "textblock.boxa", 0, 0);
boxaWrite(tempname, batb);
FREE(tempname);
boxaDestroy(&bahm);
boxaDestroy(&batm);
boxaDestroy(&batb);
}
if (ppixhm)
*ppixhm = pixhm;
else
pixDestroy(&pixhm);
if (ppixtm)
*ppixtm = pixtm;
else
pixDestroy(&pixtm);
if (ppixtb)
*ppixtb = pixtb;
else
pixDestroy(&pixtb);
return 0;
}
/*!
* pixGenTextlineMask()
*
* Input: pixs (1 bpp, assumed to be 150 to 200 ppi)
* &pixvws (<return> vertical whitespace mask)
* &tlfound (<optional return> 1 if the mask is not empty)
* debug (flag: 1 for debug output)
* Return: pixd (textline mask), or null on error
*
* Notes:
* (1) The input pixs should be deskewed.
* (2) pixs should have no halftone pixels.
* (3) Both the input image and the returned textline mask
* are at the same resolution.
*/
PIX *
pixGenTextlineMask(PIX *pixs,
PIX **ppixvws,
l_int32 *ptlfound,
l_int32 debug)
{
l_int32 empty;
PIX *pixt1, *pixt2, *pixvws, *pixd;
PROCNAME("pixGenTextlineMask");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (!ppixvws)
return (PIX *)ERROR_PTR("&pixvws not defined", procName, NULL);
if (pixGetDepth(pixs) != 1)
return (PIX *)ERROR_PTR("pixs not 1 bpp", procName, NULL);
/* First we need a vertical whitespace mask. Invert the image. */
pixt1 = pixInvert(NULL, pixs);
/* The whitespace mask will break textlines where there
* is a large amount of white space below or above.
* This can be prevented by identifying regions of the
* inverted image that have large horizontal extent (bigger than
* the separation between columns) and significant
* vertical extent (bigger than the separation between
* textlines), and subtracting this from the bg. */
pixt2 = pixMorphCompSequence(pixt1, "o80.60", 0);
pixSubtract(pixt1, pixt1, pixt2);
pixDisplayWriteFormat(pixt1, debug, IFF_PNG);
pixDestroy(&pixt2);
/* Identify vertical whitespace by opening the remaining bg.
* o5.1 removes thin vertical bg lines and o1.200 extracts
* long vertical bg lines. */
pixvws = pixMorphCompSequence(pixt1, "o5.1 + o1.200", 0);
*ppixvws = pixvws;
pixDisplayWriteFormat(pixvws, debug, IFF_PNG);
pixDestroy(&pixt1);
/* Three steps to getting text line mask:
* (1) close the characters and words in the textlines
* (2) open the vertical whitespace corridors back up
* (3) small opening to remove noise */
pixt1 = pixCloseSafeBrick(NULL, pixs, 30, 1);
pixDisplayWrite(pixt1, debug);
pixd = pixSubtract(NULL, pixt1, pixvws);
pixOpenBrick(pixd, pixd, 3, 3);
pixDisplayWriteFormat(pixd, debug, IFF_PNG);
pixDestroy(&pixt1);
/* Check if text line mask is empty */
if (ptlfound) {
*ptlfound = 0;
pixZero(pixd, &empty);
if (!empty)
*ptlfound = 1;
}
return pixd;
}
/*!
* Note: this method is generally inferior to pixHasColorRegions(); it
* is retained as a reference only
*
* \brief pixFindColorRegionsLight()
*
* \param[in] pixs 32 bpp rgb
* \param[in] pixm [optional] 1 bpp mask image
* \param[in] factor subsample factor; integer >= 1
* \param[in] darkthresh threshold to eliminate dark pixels (e.g., text)
* from consideration; typ. 70; -1 for default.
* \param[in] lightthresh threshold for minimum gray value at 95% rank
* near white; typ. 220; -1 for default
* \param[in] mindiff minimum difference from 95% rank value, used
* to count darker pixels; typ. 50; -1 for default
* \param[in] colordiff minimum difference in (max - min) component to
* qualify as a color pixel; typ. 40; -1 for default
* \param[out] pcolorfract fraction of 'color' pixels found
* \param[out] pcolormask1 [optional] mask over background color, if any
* \param[out] pcolormask2 [optional] filtered mask over background color
* \param[out] pixadb [optional] debug intermediate results
* \return 0 if OK, 1 on error
*
* <pre>
* Notes:
* (1) This function tries to determine if there is a significant
* color or darker region on a scanned page image where part
* of the image is very close to "white". It will also allow
* extraction of small regions of lightly colored pixels.
* If the background is darker (and reddish), use instead
* pixHasColorRegions2().
* (2) If %pixm exists, only pixels under fg are considered. Typically,
* the inverse of %pixm would have fg pixels over a photograph.
* (3) There are four thresholds.
* * %darkthresh: ignore pixels darker than this (typ. fg text).
* We make a 1 bpp mask of these pixels, and then dilate it to
* remove all vestiges of fg from their vicinity.
* * %lightthresh: let val95 be the pixel value for which 95%
* of the non-masked pixels have a lower value (darker) of
* their min component. Then if val95 is darker than
* %lightthresh, the image is not considered to have a
* light bg, and this returns 0.0 for %colorfract.
* * %mindiff: we are interested in the fraction of pixels that
* have two conditions. The first is that their min component
* is at least %mindiff darker than val95.
* * %colordiff: the second condition is that the max-min diff
* of the pixel components exceeds %colordiff.
* (4) This returns in %pcolorfract the fraction of pixels that have
* both a min component that is at least %mindiff below that at the
* 95% rank value (where 100% rank is the lightest value), and
* a max-min diff that is at least %colordiff. Without the
* %colordiff constraint, gray pixels of intermediate value
* could get flagged by this function.
* (5) No masks are returned unless light color pixels are found.
* If colorfract > 0.0 and %pcolormask1 is defined, this returns
* a 1 bpp mask with fg pixels over the color background.
* This mask may have some holes in it.
* (6) If colorfract > 0.0 and %pcolormask2 is defined, this returns
* a filtered version of colormask1. The two changes are
* (a) small holes have been filled
* (b) components near the border have been removed.
* The latter insures that dark pixels near the edge of the
* image are not included.
* (7) To generate a boxa of rectangular regions from the overlap
* of components in the filtered mask:
* boxa1 = pixConnCompBB(colormask2, 8);
* boxa2 = boxaCombineOverlaps(boxa1);
* This is done here in debug mode.
* </pre>
*/
static l_int32
pixFindColorRegionsLight(PIX *pixs,
PIX *pixm,
l_int32 factor,
l_int32 darkthresh,
l_int32 lightthresh,
l_int32 mindiff,
l_int32 colordiff,
l_float32 *pcolorfract,
PIX **pcolormask1,
PIX **pcolormask2,
PIXA *pixadb)
{
l_int32 lightbg, w, h, count;
l_float32 ratio, val95, rank;
BOXA *boxa1, *boxa2;
NUMA *nah;
PIX *pix1, *pix2, *pix3, *pix4, *pix5, *pixm1, *pixm2, *pixm3;
PROCNAME("pixFindColorRegionsLight");
if (pcolormask1) *pcolormask1 = NULL;
if (pcolormask2) *pcolormask2 = NULL;
if (!pcolorfract)
return ERROR_INT("&colorfract not defined", procName, 1);
*pcolorfract = 0.0;
if (!pixs || pixGetDepth(pixs) != 32)
return ERROR_INT("pixs not defined or not 32 bpp", procName, 1);
if (factor < 1) factor = 1;
if (darkthresh < 0) darkthresh = 70; /* defaults */
if (lightthresh < 0) lightthresh = 220;
if (mindiff < 0) mindiff = 50;
if (colordiff < 0) colordiff = 40;
/* Check if pixm covers most of the image. If so, just return. */
pixGetDimensions(pixs, &w, &h, NULL);
if (pixm) {
pixCountPixels(pixm, &count, NULL);
ratio = (l_float32)count / ((l_float32)(w) * h);
if (ratio > 0.7) {
if (pixadb) L_INFO("pixm has big fg: %f5.2\n", procName, ratio);
return 0;
}
}
/* Make a mask pixm1 over the dark pixels in the image:
* convert to gray using the average of the components;
* threshold using %darkthresh; do a small dilation;
* combine with pixm. */
pix1 = pixConvertRGBToGray(pixs, 0.33, 0.34, 0.33);
if (pixadb) pixaAddPix(pixadb, pixs, L_COPY);
if (pixadb) pixaAddPix(pixadb, pix1, L_COPY);
pixm1 = pixThresholdToBinary(pix1, darkthresh);
pixDilateBrick(pixm1, pixm1, 7, 7);
if (pixadb) pixaAddPix(pixadb, pixm1, L_COPY);
if (pixm) {
pixOr(pixm1, pixm1, pixm);
if (pixadb) pixaAddPix(pixadb, pixm1, L_COPY);
}
pixDestroy(&pix1);
/* Convert to gray using the minimum component value and
* find the gray value at rank 0.95, that represents the light
* pixels in the image. If it is too dark, quit. */
pix1 = pixConvertRGBToGrayMinMax(pixs, L_SELECT_MIN);
pix2 = pixInvert(NULL, pixm1); /* pixels that are not dark */
pixGetRankValueMasked(pix1, pix2, 0, 0, factor, 0.95, &val95, &nah);
pixDestroy(&pix2);
if (pixadb) {
L_INFO("val at 0.95 rank = %5.1f\n", procName, val95);
gplotSimple1(nah, GPLOT_PNG, "/tmp/lept/histo1", "gray histo");
pix3 = pixRead("/tmp/lept/histo1.png");
pix4 = pixExpandReplicate(pix3, 2);
pixaAddPix(pixadb, pix4, L_INSERT);
pixDestroy(&pix3);
}
lightbg = (l_int32)val95 >= lightthresh;
numaDestroy(&nah);
if (!lightbg) {
pixDestroy(&pix1);
pixDestroy(&pixm1);
return 0;
}
/* Make mask pixm2 over pixels that are darker than val95 - mindiff. */
pixm2 = pixThresholdToBinary(pix1, val95 - mindiff);
if (pixadb) pixaAddPix(pixadb, pixm2, L_COPY);
pixDestroy(&pix1);
/* Make a mask pixm3 over pixels that have some color saturation,
* with a (max - min) component difference >= %colordiff,
* and combine using AND with pixm2. */
pix2 = pixConvertRGBToGrayMinMax(pixs, L_CHOOSE_MAXDIFF);
pixm3 = pixThresholdToBinary(pix2, colordiff);
pixDestroy(&pix2);
pixInvert(pixm3, pixm3); /* need pixels above threshold */
if (pixadb) pixaAddPix(pixadb, pixm3, L_COPY);
pixAnd(pixm2, pixm2, pixm3);
if (pixadb) pixaAddPix(pixadb, pixm2, L_COPY);
pixDestroy(&pixm3);
/* Subtract the dark pixels represented by pixm1.
* pixm2 now holds all the color pixels of interest */
pixSubtract(pixm2, pixm2, pixm1);
pixDestroy(&pixm1);
if (pixadb) pixaAddPix(pixadb, pixm2, L_COPY);
/* But we're not quite finished. Remove pixels from any component
* that is touching the image border. False color pixels can
* sometimes be found there if the image is much darker near
* the border, due to oxidation or reduced illumination. */
pixm3 = pixRemoveBorderConnComps(pixm2, 8);
pixDestroy(&pixm2);
if (pixadb) pixaAddPix(pixadb, pixm3, L_COPY);
/* Get the fraction of light color pixels */
pixCountPixels(pixm3, &count, NULL);
*pcolorfract = (l_float32)count / (w * h);
if (pixadb) {
if (count == 0)
L_INFO("no light color pixels found\n", procName);
else
L_INFO("fraction of light color pixels = %5.3f\n", procName,
*pcolorfract);
}
/* Debug: extract the color pixels from pixs */
if (pixadb && count > 0) {
/* Use pixm3 to extract the color pixels */
pix3 = pixCreateTemplate(pixs);
pixSetAll(pix3);
pixCombineMasked(pix3, pixs, pixm3);
pixaAddPix(pixadb, pix3, L_INSERT);
/* Use additional filtering to extract the color pixels */
pix3 = pixCloseSafeBrick(NULL, pixm3, 15, 15);
pixaAddPix(pixadb, pix3, L_INSERT);
pix5 = pixCreateTemplate(pixs);
pixSetAll(pix5);
pixCombineMasked(pix5, pixs, pix3);
pixaAddPix(pixadb, pix5, L_INSERT);
/* Get the combined bounding boxes of the mask components
* in pix3, and extract those pixels from pixs. */
boxa1 = pixConnCompBB(pix3, 8);
boxa2 = boxaCombineOverlaps(boxa1, NULL);
pix4 = pixCreateTemplate(pix3);
pixMaskBoxa(pix4, pix4, boxa2, L_SET_PIXELS);
pixaAddPix(pixadb, pix4, L_INSERT);
pix5 = pixCreateTemplate(pixs);
pixSetAll(pix5);
pixCombineMasked(pix5, pixs, pix4);
pixaAddPix(pixadb, pix5, L_INSERT);
boxaDestroy(&boxa1);
boxaDestroy(&boxa2);
pixaAddPix(pixadb, pixs, L_COPY);
}
/* Optional colormask returns */
if (pcolormask2 && count > 0)
*pcolormask2 = pixCloseSafeBrick(NULL, pixm3, 15, 15);
if (pcolormask1 && count > 0)
*pcolormask1 = pixm3;
else
pixDestroy(&pixm3);
return 0;
}
l_int32 main(int argc,
char **argv)
{
l_int32 irval, igval, ibval;
l_float32 rval, gval, bval, fract, fgfract;
L_BMF *bmf;
BOX *box;
BOXA *boxa;
FPIX *fpix;
PIX *pixs, *pix1, *pix2, *pix3, *pix4, *pix5, *pix6, *pix7;
PIX *pix8, *pix9, *pix10, *pix11, *pix12, *pix13, *pix14, *pix15;
PIXA *pixa;
L_REGPARAMS *rp;
if (regTestSetup(argc, argv, &rp))
return 1;
pixa = pixaCreate(0);
pixs = pixRead("breviar38.150.jpg");
/* pixs = pixRead("breviar32.150.jpg"); */
pixaAddPix(pixa, pixs, L_CLONE);
regTestWritePixAndCheck(rp, pixs, IFF_JFIF_JPEG); /* 0 */
pixDisplayWithTitle(pixs, 0, 0, "Input image", rp->display);
/* Extract the blue component, which is small in all the text
* regions, including in the highlight color region */
pix1 = pixGetRGBComponent(pixs, COLOR_BLUE);
pixaAddPix(pixa, pix1, L_CLONE);
regTestWritePixAndCheck(rp, pix1, IFF_JFIF_JPEG); /* 1 */
pixDisplayWithTitle(pix1, 200, 0, "Blue component", rp->display);
/* Do a background normalization, with the background set to
* approximately 200 */
pix2 = pixBackgroundNormSimple(pix1, NULL, NULL);
pixaAddPix(pixa, pix2, L_COPY);
regTestWritePixAndCheck(rp, pix2, IFF_JFIF_JPEG); /* 2 */
pixDisplayWithTitle(pix2, 400, 0, "BG normalized to 200", rp->display);
/* Do a linear transform on the gray pixels, with 50 going to
* black and 160 going to white. 50 is sufficiently low to
* make both the red and black print quite dark. Quantize
* to a few equally spaced gray levels. This is the image
* to which highlight color will be applied. */
pixGammaTRC(pix2, pix2, 1.0, 50, 160);
pix3 = pixThresholdOn8bpp(pix2, 7, 1);
pixaAddPix(pixa, pix3, L_CLONE);
regTestWritePixAndCheck(rp, pix3, IFF_JFIF_JPEG); /* 3 */
pixDisplayWithTitle(pix3, 600, 0, "Basic quantized with white bg",
rp->display);
/* Identify the regions of red text. First, make a mask
* consisting of all pixels such that (R-B)/B is larger
* than 2.0. This will have all the red, plus a lot of
* the dark pixels. */
fpix = pixComponentFunction(pixs, 1.0, 0.0, -1.0, 0.0, 0.0, 1.0);
pix4 = fpixThresholdToPix(fpix, 2.0);
pixInvert(pix4, pix4); /* red plus some dark text */
pixaAddPix(pixa, pix4, L_CLONE);
regTestWritePixAndCheck(rp, pix4, IFF_PNG); /* 4 */
pixDisplayWithTitle(pix4, 800, 0, "Red plus dark pixels", rp->display);
/* Make a mask consisting of all the red and background pixels */
pix5 = pixGetRGBComponent(pixs, COLOR_RED);
pix6 = pixThresholdToBinary(pix5, 128);
pixInvert(pix6, pix6); /* red plus background (white) */
/* Intersect the two masks to get a mask consisting of pixels
* that are almost certainly red. This is the seed. */
pix7 = pixAnd(NULL, pix4, pix6); /* red only (seed) */
pixaAddPix(pixa, pix7, L_COPY);
regTestWritePixAndCheck(rp, pix7, IFF_PNG); /* 5 */
pixDisplayWithTitle(pix7, 0, 600, "Seed for red color", rp->display);
/* Make the clipping mask by thresholding the image with
* the background cleaned to white. */
pix8 = pixThresholdToBinary(pix2, 230); /* mask */
pixaAddPix(pixa, pix8, L_CLONE);
regTestWritePixAndCheck(rp, pix8, IFF_PNG); /* 6 */
pixDisplayWithTitle(pix8, 200, 600, "Clipping mask for red components",
rp->display);
/* Fill into the mask from the seed */
pixSeedfillBinary(pix7, pix7, pix8, 8); /* filled: red plus touching */
regTestWritePixAndCheck(rp, pix7, IFF_PNG); /* 7 */
pixDisplayWithTitle(pix7, 400, 600, "Red component mask filled",
rp->display);
/* Remove long horizontal and vertical lines from the filled result */
pix9 = pixMorphSequence(pix7, "o40.1", 0);
pixSubtract(pix7, pix7, pix9); /* remove long horizontal lines */
pixDestroy(&pix9);
pix9 = pixMorphSequence(pix7, "o1.40", 0);
pixSubtract(pix7, pix7, pix9); /* remove long vertical lines */
/* Close the regions to be colored */
pix10 = pixMorphSequence(pix7, "c5.1", 0);
pixaAddPix(pixa, pix10, L_CLONE);
regTestWritePixAndCheck(rp, pix10, IFF_PNG); /* 8 */
pixDisplayWithTitle(pix10, 600, 600,
"Components defining regions allowing coloring",
rp->display);
/* Sanity check on amount to be colored. Only accept images
* with less than 10% of all the pixels with highlight color */
pixForegroundFraction(pix10, &fgfract);
if (fgfract >= 0.10) {
L_INFO("too much highlighting: fract = %6.3f; removing it\n",
rp->testname, fgfract);
pixClearAll(pix10);
pixSetPixel(pix10, 0, 0, 1);
}
/* Get the bounding boxes of the regions to be colored */
boxa = pixConnCompBB(pix10, 8);
/* Get a color to paint that is representative of the
* actual highlight color in the image. Scale each
* color component up from the average by an amount necessary
* to saturate the red. Then divide the green and
* blue components by 2.0. */
pixGetAverageMaskedRGB(pixs, pix7, 0, 0, 1, L_MEAN_ABSVAL,
&rval, &gval, &bval);
fract = 255.0 / rval;
irval = lept_roundftoi(fract * rval);
igval = lept_roundftoi(fract * gval / 2.0);
ibval = lept_roundftoi(fract * bval / 2.0);
fprintf(stderr, "(r,g,b) = (%d,%d,%d)\n", irval, igval, ibval);
/* Color the quantized gray version in the selected regions */
pix11 = pixColorGrayRegions(pix3, boxa, L_PAINT_DARK, 220, irval,
igval, ibval);
pixaAddPix(pixa, pix11, L_CLONE);
regTestWritePixAndCheck(rp, pix11, IFF_PNG); /* 9 */
pixDisplayWithTitle(pix11, 800, 600, "Final colored result", rp->display);
pixaAddPix(pixa, pixs, L_CLONE);
/* Test colorization on gray and cmapped gray */
pix12 = pixColorGrayRegions(pix2, boxa, L_PAINT_DARK, 220, 0, 255, 0);
pixaAddPix(pixa, pix12, L_CLONE);
regTestWritePixAndCheck(rp, pix12, IFF_PNG); /* 10 */
pixDisplayWithTitle(pix12, 900, 600, "Colorizing boxa gray", rp->display);
box = boxCreate(200, 200, 250, 350);
pix13 = pixCopy(NULL, pix2);
pixColorGray(pix13, box, L_PAINT_DARK, 220, 0, 0, 255);
pixaAddPix(pixa, pix13, L_CLONE);
regTestWritePixAndCheck(rp, pix13, IFF_PNG); /* 11 */
pixDisplayWithTitle(pix13, 1000, 600, "Colorizing box gray", rp->display);
pix14 = pixThresholdTo4bpp(pix2, 6, 1);
pix15 = pixColorGrayRegions(pix14, boxa, L_PAINT_DARK, 220, 0, 0, 255);
pixaAddPix(pixa, pix15, L_CLONE);
regTestWritePixAndCheck(rp, pix15, IFF_PNG); /* 12 */
pixDisplayWithTitle(pix15, 1100, 600, "Colorizing boxa cmap", rp->display);
pixColorGrayCmap(pix14, box, L_PAINT_DARK, 0, 255, 255);
pixaAddPix(pixa, pix14, L_CLONE);
regTestWritePixAndCheck(rp, pix14, IFF_PNG); /* 13 */
pixDisplayWithTitle(pix14, 1200, 600, "Colorizing box cmap", rp->display);
boxDestroy(&box);
/* Generate a pdf of the intermediate results */
lept_mkdir("lept");
L_INFO("Writing to /tmp/lept/colorize.pdf\n", rp->testname);
pixaConvertToPdf(pixa, 90, 1.0, 0, 0, "Colorizing highlighted text",
"/tmp/lept/colorize.pdf");
pixaDestroy(&pixa);
fpixDestroy(&fpix);
boxDestroy(&box);
boxaDestroy(&boxa);
pixDestroy(&pixs);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
pixDestroy(&pix4);
pixDestroy(&pix5);
pixDestroy(&pix6);
pixDestroy(&pix7);
pixDestroy(&pix8);
pixDestroy(&pix9);
pixDestroy(&pix10);
pixDestroy(&pix11);
pixDestroy(&pix12);
pixDestroy(&pix13);
pixDestroy(&pix14);
pixDestroy(&pix15);
/* Test the color detector */
pixa = pixaCreate(7);
bmf = bmfCreate("./fonts", 4);
pix1 = TestForRedColor(rp, "brev06.75.jpg", 1, bmf); /* 14 */
pixaAddPix(pixa, pix1, L_INSERT);
pix1 = TestForRedColor(rp, "brev10.75.jpg", 0, bmf); /* 15 */
pixaAddPix(pixa, pix1, L_INSERT);
pix1 = TestForRedColor(rp, "brev14.75.jpg", 1, bmf); /* 16 */
pixaAddPix(pixa, pix1, L_INSERT);
pix1 = TestForRedColor(rp, "brev20.75.jpg", 1, bmf); /* 17 */
pixaAddPix(pixa, pix1, L_INSERT);
pix1 = TestForRedColor(rp, "brev36.75.jpg", 0, bmf); /* 18 */
pixaAddPix(pixa, pix1, L_INSERT);
pix1 = TestForRedColor(rp, "brev53.75.jpg", 1, bmf); /* 19 */
pixaAddPix(pixa, pix1, L_INSERT);
pix1 = TestForRedColor(rp, "brev56.75.jpg", 1, bmf); /* 20 */
pixaAddPix(pixa, pix1, L_INSERT);
/* Generate a pdf of the color detector results */
L_INFO("Writing to /tmp/lept/colordetect.pdf\n", rp->testname);
pixaConvertToPdf(pixa, 45, 1.0, 0, 0, "Color detection",
"/tmp/lept/colordetect.pdf");
pixaDestroy(&pixa);
bmfDestroy(&bmf);
return regTestCleanup(rp);
}
l_int32
DoPageSegmentation(PIX *pixs, /* should be at least 300 ppi */
l_int32 which) /* 1, 2, 3, 4 */
{
char buf[256];
l_int32 zero;
BOXA *boxatm, *boxahm;
PIX *pixr; /* image reduced to 150 ppi */
PIX *pixhs; /* image of halftone seed, 150 ppi */
PIX *pixm; /* image of mask of components, 150 ppi */
PIX *pixhm1; /* image of halftone mask, 150 ppi */
PIX *pixhm2; /* image of halftone mask, 300 ppi */
PIX *pixht; /* image of halftone components, 150 ppi */
PIX *pixnht; /* image without halftone components, 150 ppi */
PIX *pixi; /* inverted image, 150 ppi */
PIX *pixvws; /* image of vertical whitespace, 150 ppi */
PIX *pixm1; /* image of closed textlines, 150 ppi */
PIX *pixm2; /* image of refined text line mask, 150 ppi */
PIX *pixm3; /* image of refined text line mask, 300 ppi */
PIX *pixb1; /* image of text block mask, 150 ppi */
PIX *pixb2; /* image of text block mask, 300 ppi */
PIX *pixnon; /* image of non-text or halftone, 150 ppi */
PIX *pix1, *pix2, *pix3, *pix4;
PIXA *pixa;
PIXCMAP *cmap;
PTAA *ptaa;
l_int32 ht_flag = 0;
l_int32 ws_flag = 0;
l_int32 text_flag = 0;
l_int32 block_flag = 0;
PROCNAME("DoPageSegmentation");
if (which == 1)
ht_flag = 1;
else if (which == 2)
ws_flag = 1;
else if (which == 3)
text_flag = 1;
else if (which == 4)
block_flag = 1;
else
return ERROR_INT("invalid parameter: not in [1...4]", procName, 1);
pixa = pixaCreate(0);
lept_mkdir("lept/livre");
/* Reduce to 150 ppi */
pix1 = pixScaleToGray2(pixs);
if (ws_flag || ht_flag || block_flag) pixaAddPix(pixa, pix1, L_COPY);
if (which == 1)
pixWrite("/tmp/lept/livre/orig.gray.150.png", pix1, IFF_PNG);
pixDestroy(&pix1);
pixr = pixReduceRankBinaryCascade(pixs, 1, 0, 0, 0);
/* Get seed for halftone parts */
pix1 = pixReduceRankBinaryCascade(pixr, 4, 4, 3, 0);
pix2 = pixOpenBrick(NULL, pix1, 5, 5);
pixhs = pixExpandBinaryPower2(pix2, 8);
if (ht_flag) pixaAddPix(pixa, pixhs, L_COPY);
if (which == 1)
pixWrite("/tmp/lept/livre/htseed.150.png", pixhs, IFF_PNG);
pixDestroy(&pix1);
pixDestroy(&pix2);
/* Get mask for connected regions */
pixm = pixCloseSafeBrick(NULL, pixr, 4, 4);
if (ht_flag) pixaAddPix(pixa, pixm, L_COPY);
if (which == 1)
pixWrite("/tmp/lept/livre/ccmask.150.png", pixm, IFF_PNG);
/* Fill seed into mask to get halftone mask */
pixhm1 = pixSeedfillBinary(NULL, pixhs, pixm, 4);
if (ht_flag) pixaAddPix(pixa, pixhm1, L_COPY);
if (which == 1) pixWrite("/tmp/lept/livre/htmask.150.png", pixhm1, IFF_PNG);
pixhm2 = pixExpandBinaryPower2(pixhm1, 2);
/* Extract halftone stuff */
pixht = pixAnd(NULL, pixhm1, pixr);
if (which == 1) pixWrite("/tmp/lept/livre/ht.150.png", pixht, IFF_PNG);
/* Extract non-halftone stuff */
pixnht = pixXor(NULL, pixht, pixr);
if (text_flag) pixaAddPix(pixa, pixnht, L_COPY);
if (which == 1) pixWrite("/tmp/lept/livre/text.150.png", pixnht, IFF_PNG);
pixZero(pixht, &zero);
if (zero)
fprintf(stderr, "No halftone parts found\n");
else
fprintf(stderr, "Halftone parts found\n");
/* Get bit-inverted image */
pixi = pixInvert(NULL, pixnht);
if (ws_flag) pixaAddPix(pixa, pixi, L_COPY);
if (which == 1) pixWrite("/tmp/lept/livre/invert.150.png", pixi, IFF_PNG);
/* The whitespace mask will break textlines where there
* is a large amount of white space below or above.
* We can prevent this by identifying regions of the
* inverted image that have large horizontal (bigger than
* the separation between columns) and significant
* vertical extent (bigger than the separation between
* textlines), and subtracting this from the whitespace mask. */
pix1 = pixMorphCompSequence(pixi, "o80.60", 0);
pix2 = pixSubtract(NULL, pixi, pix1);
if (ws_flag) pixaAddPix(pixa, pix2, L_COPY);
pixDestroy(&pix1);
/* Identify vertical whitespace by opening inverted image */
pix3 = pixOpenBrick(NULL, pix2, 5, 1); /* removes thin vertical lines */
pixvws = pixOpenBrick(NULL, pix3, 1, 200); /* gets long vertical lines */
if (text_flag || ws_flag) pixaAddPix(pixa, pixvws, L_COPY);
if (which == 1) pixWrite("/tmp/lept/livre/vertws.150.png", pixvws, IFF_PNG);
pixDestroy(&pix2);
pixDestroy(&pix3);
/* Get proto (early processed) text line mask. */
/* First close the characters and words in the textlines */
pixm1 = pixCloseSafeBrick(NULL, pixnht, 30, 1);
if (text_flag) pixaAddPix(pixa, pixm1, L_COPY);
if (which == 1)
pixWrite("/tmp/lept/livre/textmask1.150.png", pixm1, IFF_PNG);
/* Next open back up the vertical whitespace corridors */
pixm2 = pixSubtract(NULL, pixm1, pixvws);
if (which == 1)
pixWrite("/tmp/lept/livre/textmask2.150.png", pixm2, IFF_PNG);
/* Do a small opening to remove noise */
pixOpenBrick(pixm2, pixm2, 3, 3);
if (text_flag) pixaAddPix(pixa, pixm2, L_COPY);
if (which == 1)
pixWrite("/tmp/lept/livre/textmask3.150.png", pixm2, IFF_PNG);
pixm3 = pixExpandBinaryPower2(pixm2, 2);
/* Join pixels vertically to make text block mask */
pixb1 = pixMorphSequence(pixm2, "c1.10 + o4.1", 0);
if (block_flag) pixaAddPix(pixa, pixb1, L_COPY);
if (which == 1)
pixWrite("/tmp/lept/livre/textblock1.150.png", pixb1, IFF_PNG);
/* Solidify the textblock mask and remove noise:
* (1) For each c.c., close the blocks and dilate slightly
* to form a solid mask.
* (2) Small horizontal closing between components
* (3) Open the white space between columns, again
* (4) Remove small components */
pix1 = pixMorphSequenceByComponent(pixb1, "c30.30 + d3.3", 8, 0, 0, NULL);
pixCloseSafeBrick(pix1, pix1, 10, 1);
if (block_flag) pixaAddPix(pixa, pix1, L_COPY);
pix2 = pixSubtract(NULL, pix1, pixvws);
pix3 = pixSelectBySize(pix2, 25, 5, 8, L_SELECT_IF_BOTH,
L_SELECT_IF_GTE, NULL);
if (block_flag) pixaAddPix(pixa, pix3, L_COPY);
if (which == 1)
pixWrite("/tmp/lept/livre/textblock2.150.png", pix3, IFF_PNG);
pixb2 = pixExpandBinaryPower2(pix3, 2);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
/* Identify the outlines of each textblock */
ptaa = pixGetOuterBordersPtaa(pixb2);
pix1 = pixRenderRandomCmapPtaa(pixb2, ptaa, 1, 8, 1);
cmap = pixGetColormap(pix1);
pixcmapResetColor(cmap, 0, 130, 130, 130); /* set interior to gray */
if (which == 1)
pixWrite("/tmp/lept/livre/textblock3.300.png", pix1, IFF_PNG);
pixDisplayWithTitle(pix1, 480, 360, "textblock mask with outlines", DFLAG);
ptaaDestroy(&ptaa);
pixDestroy(&pix1);
/* Fill line mask (as seed) into the original */
pix1 = pixSeedfillBinary(NULL, pixm3, pixs, 8);
pixOr(pixm3, pixm3, pix1);
pixDestroy(&pix1);
if (which == 1)
pixWrite("/tmp/lept/livre/textmask.300.png", pixm3, IFF_PNG);
pixDisplayWithTitle(pixm3, 480, 360, "textline mask 4", DFLAG);
/* Fill halftone mask (as seed) into the original */
pix1 = pixSeedfillBinary(NULL, pixhm2, pixs, 8);
pixOr(pixhm2, pixhm2, pix1);
pixDestroy(&pix1);
if (which == 1)
pixWrite("/tmp/lept/livre/htmask.300.png", pixhm2, IFF_PNG);
pixDisplayWithTitle(pixhm2, 520, 390, "halftonemask 2", DFLAG);
/* Find objects that are neither text nor halftones */
pix1 = pixSubtract(NULL, pixs, pixm3); /* remove text pixels */
pixnon = pixSubtract(NULL, pix1, pixhm2); /* remove halftone pixels */
pixDestroy(&pix1);
if (which == 1)
pixWrite("/tmp/lept/livre/other.300.png", pixnon, IFF_PNG);
pixDisplayWithTitle(pixnon, 540, 420, "other stuff", DFLAG);
/* Write out b.b. for text line mask and halftone mask components */
boxatm = pixConnComp(pixm3, NULL, 4);
boxahm = pixConnComp(pixhm2, NULL, 8);
if (which == 1) {
boxaWrite("/tmp/lept/livre/textmask.boxa", boxatm);
boxaWrite("/tmp/lept/livre/htmask.boxa", boxahm);
}
pix1 = pixaDisplayTiledAndScaled(pixa, 8, 250, 4, 0, 25, 2);
pixDisplay(pix1, 0, 375 * (which - 1));
snprintf(buf, sizeof(buf), "/tmp/lept/livre/segout.%d.png", which);
pixWrite(buf, pix1, IFF_PNG);
pixDestroy(&pix1);
pixaDestroy(&pixa);
/* clean up to test with valgrind */
pixDestroy(&pixr);
pixDestroy(&pixhs);
pixDestroy(&pixm);
pixDestroy(&pixhm1);
pixDestroy(&pixhm2);
pixDestroy(&pixht);
pixDestroy(&pixi);
pixDestroy(&pixnht);
pixDestroy(&pixvws);
pixDestroy(&pixm1);
pixDestroy(&pixm2);
pixDestroy(&pixm3);
pixDestroy(&pixb1);
pixDestroy(&pixb2);
pixDestroy(&pixnon);
boxaDestroy(&boxatm);
boxaDestroy(&boxahm);
return 0;
}
main(int argc,
char **argv)
{
char *filein;
l_int32 count;
CCBORDA *ccba, *ccba2;
PIX *pixs, *pixd, *pixd2, *pixd3;
PIX *pixt, *pixc, *pixc2;
static char mainName[] = "ccbordtest";
if (argc != 2)
exit(ERROR_INT(" Syntax: ccbordtest filein", mainName, 1));
filein = argv[1];
if ((pixs = pixRead(filein)) == NULL)
exit(ERROR_INT("pixs not made", mainName, 1));
fprintf(stderr, "Get border representation...");
startTimer();
ccba = pixGetAllCCBorders(pixs);
fprintf(stderr, "%6.3f sec\n", stopTimer());
#if 0
/* get global locs directly and display borders */
fprintf(stderr, "Convert from local to global locs...");
startTimer();
ccbaGenerateGlobalLocs(ccba);
fprintf(stderr, "%6.3f sec\n", stopTimer());
fprintf(stderr, "Display border representation...");
startTimer();
pixd = ccbaDisplayBorder(ccba);
fprintf(stderr, "%6.3f sec\n", stopTimer());
pixWrite("/tmp/junkborder1.png", pixd, IFF_PNG);
#else
/* get step chain code, then global coords, and display borders */
fprintf(stderr, "Get step chain code...");
startTimer();
ccbaGenerateStepChains(ccba);
fprintf(stderr, "%6.3f sec\n", stopTimer());
fprintf(stderr, "Convert from step chain to global locs...");
startTimer();
ccbaStepChainsToPixCoords(ccba, CCB_GLOBAL_COORDS);
fprintf(stderr, "%6.3f sec\n", stopTimer());
fprintf(stderr, "Display border representation...");
startTimer();
pixd = ccbaDisplayBorder(ccba);
fprintf(stderr, "%6.3f sec\n", stopTimer());
pixWrite("/tmp/junkborder1.png", pixd, IFF_PNG);
#endif
/* check if border pixels are in original set */
fprintf(stderr, "Check if border pixels are in original set ...\n");
pixt = pixSubtract(NULL, pixd, pixs);
pixCountPixels(pixt, &count, NULL);
if (count == 0)
fprintf(stderr, " all border pixels are in original set\n");
else
fprintf(stderr, " %d border pixels are not in original set\n", count);
pixDestroy(&pixt);
/* display image */
fprintf(stderr, "Reconstruct image ...");
startTimer();
/* pixc = ccbaDisplayImage1(ccba); */
pixc = ccbaDisplayImage2(ccba);
fprintf(stderr, "%6.3f sec\n", stopTimer());
pixWrite("/tmp/junkrecon1.png", pixc, IFF_PNG);
/* check with original to see if correct */
fprintf(stderr, "Check with original to see if correct ...\n");
pixXor(pixc, pixc, pixs);
pixCountPixels(pixc, &count, NULL);
if (count == 0)
fprintf(stderr, " perfect direct recon\n");
else {
l_int32 w, h, i, j;
l_uint32 val;
fprintf(stderr, " %d pixels in error in recon\n", count);
#if 1
w = pixGetWidth(pixc);
h = pixGetHeight(pixc);
for (i = 0; i < h; i++) {
for (j = 0; j < w; j++) {
pixGetPixel(pixc, j, i, &val);
if (val == 1)
fprintf(stderr, "bad pixel at (%d, %d)\n", j, i);
}
}
pixWrite("/tmp/junkbadpixels.png", pixc, IFF_PNG);
#endif
}
/*----------------------------------------------------------*
* write to file (compressed) and read back *
*----------------------------------------------------------*/
fprintf(stderr, "Write serialized step data...");
startTimer();
ccbaWrite("/tmp/junkstepout", ccba);
fprintf(stderr, "%6.3f sec\n", stopTimer());
fprintf(stderr, "Read serialized step data...");
startTimer();
ccba2 = ccbaRead("/tmp/junkstepout");
fprintf(stderr, "%6.3f sec\n", stopTimer());
/* display the border pixels again */
fprintf(stderr, "Convert from step chain to global locs...");
startTimer();
ccbaStepChainsToPixCoords(ccba2, CCB_GLOBAL_COORDS);
fprintf(stderr, "%6.3f sec\n", stopTimer());
fprintf(stderr, "Display border representation...");
startTimer();
pixd2 = ccbaDisplayBorder(ccba2);
fprintf(stderr, "%6.3f sec\n", stopTimer());
pixWrite("/tmp/junkborder2.png", pixd2, IFF_PNG);
/* check if border pixels are same as first time */
pixXor(pixd2, pixd2, pixd);
pixCountPixels(pixd2, &count, NULL);
if (count == 0)
fprintf(stderr, " perfect w/r border recon\n");
else {
l_int32 w, h, i, j, val;
fprintf(stderr, " %d pixels in error in w/r recon\n", count);
}
pixDestroy(&pixd2);
/* display image again */
fprintf(stderr, "Convert from step chain to local coords...");
startTimer();
ccbaStepChainsToPixCoords(ccba2, CCB_LOCAL_COORDS);
fprintf(stderr, "%6.3f sec\n", stopTimer());
fprintf(stderr, "Reconstruct image from file ...");
startTimer();
/* pixc2 = ccbaDisplayImage1(ccba2); */
pixc2 = ccbaDisplayImage2(ccba2);
fprintf(stderr, "%6.3f sec\n", stopTimer());
pixWrite("/tmp/junkrecon2.png", pixc2, IFF_PNG);
/* check with original to see if correct */
fprintf(stderr, "Check with original to see if correct ...\n");
pixXor(pixc2, pixc2, pixs);
pixCountPixels(pixc2, &count, NULL);
if (count == 0)
fprintf(stderr, " perfect image recon\n");
else {
l_int32 w, h, i, j;
l_uint32 val;
fprintf(stderr, " %d pixels in error in image recon\n", count);
#if 1
w = pixGetWidth(pixc2);
h = pixGetHeight(pixc2);
for (i = 0; i < h; i++) {
for (j = 0; j < w; j++) {
pixGetPixel(pixc2, j, i, &val);
if (val == 1)
fprintf(stderr, "bad pixel at (%d, %d)\n", j, i);
}
}
pixWrite("/tmp/junkbadpixels2.png", pixc2, IFF_PNG);
#endif
}
/*----------------------------------------------------------*
* make, display and check single path border for svg *
*----------------------------------------------------------*/
/* make local single path border for svg */
fprintf(stderr, "Make local single path borders for svg ...");
startTimer();
ccbaGenerateSinglePath(ccba);
fprintf(stderr, "%6.3f sec\n", stopTimer());
/* generate global single path border */
fprintf(stderr, "Generate global single path borders ...");
startTimer();
ccbaGenerateSPGlobalLocs(ccba, CCB_SAVE_TURNING_PTS);
fprintf(stderr, "%6.3f sec\n", stopTimer());
/* display border pixels from single path */
fprintf(stderr, "Display border from single path...");
startTimer();
pixd3 = ccbaDisplaySPBorder(ccba);
fprintf(stderr, "%6.3f sec\n", stopTimer());
pixWrite("/tmp/junkborder3.png", pixd3, IFF_PNG);
/* check if border pixels are in original set */
fprintf(stderr, "Check if border pixels are in original set ...\n");
pixt = pixSubtract(NULL, pixd3, pixs);
pixCountPixels(pixt, &count, NULL);
if (count == 0)
fprintf(stderr, " all border pixels are in original set\n");
else
fprintf(stderr, " %d border pixels are not in original set\n", count);
pixDestroy(&pixt);
pixDestroy(&pixd3);
/* output in svg file format */
fprintf(stderr, "Write output in svg file format ...\n");
startTimer();
ccbaWriteSVG("/tmp/junksvg", ccba);
fprintf(stderr, "%6.3f sec\n", stopTimer());
ccbaDestroy(&ccba2);
ccbaDestroy(&ccba);
pixDestroy(&pixs);
pixDestroy(&pixd);
pixDestroy(&pixc);
pixDestroy(&pixc2);
return 0;
}
int main(int argc,
char **argv)
{
PIX *pixs, *pix1, *pix2, *pix3, *pix4;
L_REGPARAMS *rp;
if (regTestSetup(argc, argv, &rp))
return 1;
pixs = pixRead("test1.png");
/* pixInvert */
pix1 = pixInvert(NULL, pixs);
pix2 = pixCreateTemplate(pixs); /* into pixd of same size */
pixInvert(pix2, pixs);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 0 */
regTestComparePix(rp, pix1, pix2); /* 1 */
pix3 = pixRead("marge.jpg"); /* into pixd of different size */
pixInvert(pix3, pixs);
regTestComparePix(rp, pix1, pix3); /* 2 */
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
pix1 = pixOpenBrick(NULL, pixs, 1, 9);
pix2 = pixDilateBrick(NULL, pixs, 1, 9);
/* pixOr */
pix3 = pixCreateTemplate(pixs);
pixOr(pix3, pixs, pix1); /* existing */
pix4 = pixOr(NULL, pixs, pix1); /* new */
regTestWritePixAndCheck(rp, pix3, IFF_PNG); /* 3 */
regTestComparePix(rp, pix3, pix4); /* 4 */
pixCopy(pix4, pix1);
pixOr(pix4, pix4, pixs); /* in-place */
regTestComparePix(rp, pix3, pix4); /* 5 */
pixDestroy(&pix3);
pixDestroy(&pix4);
pix3 = pixCreateTemplate(pixs);
pixOr(pix3, pixs, pix2); /* existing */
pix4 = pixOr(NULL, pixs, pix2); /* new */
regTestWritePixAndCheck(rp, pix3, IFF_PNG); /* 6 */
regTestComparePix(rp, pix3, pix4); /* 7 */
pixCopy(pix4, pix2);
pixOr(pix4, pix4, pixs); /* in-place */
regTestComparePix(rp, pix3, pix4); /* 8 */
pixDestroy(&pix3);
pixDestroy(&pix4);
/* pixAnd */
pix3 = pixCreateTemplate(pixs);
pixAnd(pix3, pixs, pix1); /* existing */
pix4 = pixAnd(NULL, pixs, pix1); /* new */
regTestWritePixAndCheck(rp, pix3, IFF_PNG); /* 9 */
regTestComparePix(rp, pix3, pix4); /* 10 */
pixCopy(pix4, pix1);
pixAnd(pix4, pix4, pixs); /* in-place */
regTestComparePix(rp, pix3, pix4); /* 11 */
pixDestroy(&pix3);
pixDestroy(&pix4);
pix3 = pixCreateTemplate(pixs);
pixAnd(pix3, pixs, pix2); /* existing */
pix4 = pixAnd(NULL, pixs, pix2); /* new */
regTestWritePixAndCheck(rp, pix3, IFF_PNG); /* 12 */
regTestComparePix(rp, pix3, pix4); /* 13 */
pixCopy(pix4, pix2);
pixAnd(pix4, pix4, pixs); /* in-place */
regTestComparePix(rp, pix3, pix4); /* 14 */
pixDestroy(&pix3);
pixDestroy(&pix4);
/* pixXor */
pix3 = pixCreateTemplate(pixs);
pixXor(pix3, pixs, pix1); /* existing */
pix4 = pixXor(NULL, pixs, pix1); /* new */
regTestWritePixAndCheck(rp, pix3, IFF_PNG); /* 15 */
regTestComparePix(rp, pix3, pix4); /* 16 */
pixCopy(pix4, pix1);
pixXor(pix4, pix4, pixs); /* in-place */
regTestComparePix(rp, pix3, pix4); /* 17 */
pixDestroy(&pix3);
pixDestroy(&pix4);
pix3 = pixCreateTemplate(pixs);
pixXor(pix3, pixs, pix2); /* existing */
pix4 = pixXor(NULL, pixs, pix2); /* new */
regTestWritePixAndCheck(rp, pix3, IFF_PNG); /* 18 */
regTestComparePix(rp, pix3, pix4); /* 19 */
pixCopy(pix4, pix2);
pixXor(pix4, pix4, pixs); /* in-place */
regTestComparePix(rp, pix3, pix4); /* 20 */
pixDestroy(&pix3);
pixDestroy(&pix4);
/* pixSubtract */
pix3 = pixCreateTemplate(pixs);
pixSubtract(pix3, pixs, pix1); /* existing */
pix4 = pixSubtract(NULL, pixs, pix1); /* new */
regTestWritePixAndCheck(rp, pix3, IFF_PNG); /* 21 */
regTestComparePix(rp, pix3, pix4); /* 22 */
pixCopy(pix4, pix1);
pixSubtract(pix4, pixs, pix4); /* in-place */
regTestComparePix(rp, pix3, pix4); /* 23 */
pixDestroy(&pix3);
pixDestroy(&pix4);
pix3 = pixCreateTemplate(pixs);
pixSubtract(pix3, pixs, pix2); /* existing */
pix4 = pixSubtract(NULL, pixs, pix2); /* new */
regTestWritePixAndCheck(rp, pix3, IFF_PNG); /* 24 */
regTestComparePix(rp, pix3, pix4); /* 25 */
pixCopy(pix4, pix2);
pixSubtract(pix4, pixs, pix4); /* in-place */
regTestComparePix(rp, pix3, pix4); /* 26 */
pixDestroy(&pix3);
pixDestroy(&pix4);
pix4 = pixRead("marge.jpg");
pixSubtract(pix4, pixs, pixs); /* subtract from itself; should be empty */
pix3 = pixCreateTemplate(pixs);
regTestComparePix(rp, pix3, pix4); /* 27*/
pixDestroy(&pix3);
pixDestroy(&pix4);
pixSubtract(pixs, pixs, pixs); /* subtract from itself; should be empty */
pix3 = pixCreateTemplate(pixs);
regTestComparePix(rp, pix3, pixs); /* 28*/
pixDestroy(&pix3);
pixDestroy(&pixs);
pixDestroy(&pix1);
pixDestroy(&pix2);
return regTestCleanup(rp);
}