/*!
* 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;
}
/*!
* \brief fpixaDisplayQuadtree()
*
* \param[in] fpixa mean, variance or root variance
* \param[in] factor replication factor at lowest level
* \param[in] fontsize 4, ... 20
* \return pixd 8 bpp, mosaic of quadtree images, or NULL on error
*
* <pre>
* Notes:
* (1) The mean and root variance fall naturally in the 8 bpp range,
* but the variance is typically outside the range. This
* function displays 8 bpp pix clipped to 255, so the image
* pixels will mostly be 255 (white).
* </pre>
*/
PIX *
fpixaDisplayQuadtree(FPIXA *fpixa,
l_int32 factor,
l_int32 fontsize)
{
char buf[256];
l_int32 nlevels, i, mag, w;
L_BMF *bmf;
FPIX *fpix;
PIX *pixt1, *pixt2, *pixt3, *pixt4, *pixd;
PIXA *pixat;
PROCNAME("fpixaDisplayQuadtree");
if (!fpixa)
return (PIX *)ERROR_PTR("fpixa not defined", procName, NULL);
if ((nlevels = fpixaGetCount(fpixa)) == 0)
return (PIX *)ERROR_PTR("pixas empty", procName, NULL);
if ((bmf = bmfCreate(NULL, fontsize)) == NULL)
L_ERROR("bmf not made; text will not be added", procName);
pixat = pixaCreate(nlevels);
for (i = 0; i < nlevels; i++) {
fpix = fpixaGetFPix(fpixa, i, L_CLONE);
pixt1 = fpixConvertToPix(fpix, 8, L_CLIP_TO_ZERO, 0);
mag = factor * (1 << (nlevels - i - 1));
pixt2 = pixExpandReplicate(pixt1, mag);
pixt3 = pixConvertTo32(pixt2);
snprintf(buf, sizeof(buf), "Level %d\n", i);
pixt4 = pixAddSingleTextblock(pixt3, bmf, buf, 0xff000000,
L_ADD_BELOW, NULL);
pixaAddPix(pixat, pixt4, L_INSERT);
fpixDestroy(&fpix);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
pixDestroy(&pixt3);
}
w = pixGetWidth(pixt4);
pixd = pixaDisplayTiledInRows(pixat, 32, nlevels * (w + 80), 1.0, 0, 30, 2);
pixaDestroy(&pixat);
bmfDestroy(&bmf);
return pixd;
}
/*!
* pixMorphCompSequenceDwa()
*
* Input: pixs
* sequence (string specifying sequence)
* dispsep (horizontal separation in pixels between
* successive displays; use zero to suppress display)
* Return: pixd, or null on error
*
* Notes:
* (1) This does dwa morphology on binary images, using brick Sels.
* (2) This runs a pipeline of operations; no branching is allowed.
* (3) It implements all brick Sels that have dimensions up to 63
* on each side, using a composite (linear + comb) when useful.
* (4) A new image is always produced; the input image is not changed.
* (5) This contains an interpreter, allowing sequences to be
* generated and run.
* (6) See pixMorphSequence() for further information about usage.
*/
PIX *
pixMorphCompSequenceDwa(PIX *pixs,
const char *sequence,
l_int32 dispsep)
{
char *rawop, *op;
l_int32 nops, i, j, nred, fact, w, h, x, y, border;
l_int32 level[4];
PIX *pixt1, *pixt2;
SARRAY *sa;
PROCNAME("pixMorphCompSequenceDwa");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (!sequence)
return (PIX *)ERROR_PTR("sequence not defined", procName, NULL);
/* Split sequence into individual operations */
sa = sarrayCreate(0);
sarraySplitString(sa, sequence, "+");
nops = sarrayGetCount(sa);
if (!morphSequenceVerify(sa)) {
sarrayDestroy(&sa);
return (PIX *)ERROR_PTR("sequence not valid", procName, NULL);
}
/* Parse and operate */
border = 0;
pixt1 = pixCopy(NULL, pixs);
pixt2 = NULL;
x = y = 0;
for (i = 0; i < nops; i++) {
rawop = sarrayGetString(sa, i, 0);
op = stringRemoveChars(rawop, " \n\t");
switch (op[0])
{
case 'd':
case 'D':
sscanf(&op[1], "%d.%d", &w, &h);
pixt2 = pixDilateCompBrickDwa(NULL, pixt1, w, h);
pixDestroy(&pixt1);
pixt1 = pixClone(pixt2);
pixDestroy(&pixt2);
if (dispsep > 0) {
pixDisplay(pixt1, x, y);
x += dispsep;
}
break;
case 'e':
case 'E':
sscanf(&op[1], "%d.%d", &w, &h);
pixt2 = pixErodeCompBrickDwa(NULL, pixt1, w, h);
pixDestroy(&pixt1);
pixt1 = pixClone(pixt2);
pixDestroy(&pixt2);
if (dispsep > 0) {
pixDisplay(pixt1, x, y);
x += dispsep;
}
break;
case 'o':
case 'O':
sscanf(&op[1], "%d.%d", &w, &h);
pixOpenCompBrickDwa(pixt1, pixt1, w, h);
if (dispsep > 0) {
pixDisplay(pixt1, x, y);
x += dispsep;
}
break;
case 'c':
case 'C':
sscanf(&op[1], "%d.%d", &w, &h);
pixCloseCompBrickDwa(pixt1, pixt1, w, h);
if (dispsep > 0) {
pixDisplay(pixt1, x, y);
x += dispsep;
}
break;
case 'r':
case 'R':
nred = strlen(op) - 1;
for (j = 0; j < nred; j++)
level[j] = op[j + 1] - '0';
for (j = nred; j < 4; j++)
level[j] = 0;
pixt2 = pixReduceRankBinaryCascade(pixt1, level[0], level[1],
level[2], level[3]);
pixDestroy(&pixt1);
pixt1 = pixClone(pixt2);
pixDestroy(&pixt2);
if (dispsep > 0) {
pixDisplay(pixt1, x, y);
x += dispsep;
}
break;
case 'x':
case 'X':
sscanf(&op[1], "%d", &fact);
pixt2 = pixExpandReplicate(pixt1, fact);
pixDestroy(&pixt1);
pixt1 = pixClone(pixt2);
pixDestroy(&pixt2);
if (dispsep > 0) {
pixDisplay(pixt1, x, y);
x += dispsep;
}
break;
case 'b':
case 'B':
sscanf(&op[1], "%d", &border);
pixt2 = pixAddBorder(pixt1, border, 0);
pixDestroy(&pixt1);
pixt1 = pixClone(pixt2);
pixDestroy(&pixt2);
if (dispsep > 0) {
pixDisplay(pixt1, x, y);
x += dispsep;
}
break;
default:
/* All invalid ops are caught in the first pass */
break;
}
FREE(op);
}
if (border > 0) {
pixt2 = pixRemoveBorder(pixt1, border);
pixDestroy(&pixt1);
pixt1 = pixClone(pixt2);
pixDestroy(&pixt2);
}
sarrayDestroy(&sa);
return pixt1;
}
/*!
* 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;
}
main(int argc,
char **argv)
{
l_int32 i;
l_float32 pi, scale, angle;
PIX *pixc, *pixm, *pix1, *pix2, *pix3;
PIXA *pixa;
PTA *pta1, *pta2, *pta3, *pta4;
static char mainName[] = "smallpix_reg";
/* Make a small test image, the hard way! */
pi = 3.1415926535;
pixc = pixCreate(9, 9, 32);
pixm = pixCreate(9, 9, 1);
pta1 = generatePtaLineFromPt(4, 4, 3.1, 0.0);
pta2 = generatePtaLineFromPt(4, 4, 3.1, 0.5 * pi);
pta3 = generatePtaLineFromPt(4, 4, 3.1, pi);
pta4 = generatePtaLineFromPt(4, 4, 3.1, 1.5 * pi);
ptaJoin(pta1, pta2, 0, 0);
ptaJoin(pta1, pta3, 0, 0);
ptaJoin(pta1, pta4, 0, 0);
pixRenderPta(pixm, pta1, L_SET_PIXELS);
pixPaintThroughMask(pixc, pixm, 0, 0, 0x00ff0000);
ptaDestroy(&pta1);
ptaDestroy(&pta2);
ptaDestroy(&pta3);
ptaDestroy(&pta4);
pixDestroy(&pixm);
/* Results differ for scaleSmoothLow() w/ and w/out + 0.5.
* Neither is properly symmetric (with symm pattern on odd-sized
* pix, because the smoothing is destroying the symmetry. */
pixa = pixaCreate(11);
pix1 = pixExpandReplicate(pixc, 2);
for (i = 0; i < 11; i++) {
scale = 0.30 + 0.035 * (l_float32)i;
pix2 = pixScaleSmooth(pix1, scale, scale);
pix3 = pixExpandReplicate(pix2, 6);
pixSaveTiled(pix3, pixa, 1, (i == 0), 20, 32);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pixDestroy(&pix1);
DisplayPix(&pixa, 100, 100, NULL);
/* Results same for pixScaleAreaMap w/ and w/out + 0.5 */
pixa = pixaCreate(11);
pix1 = pixExpandReplicate(pixc, 2);
for (i = 0; i < 11; i++) {
scale = 0.30 + 0.035 * (l_float32)i;
pix2 = pixScaleAreaMap(pix1, scale, scale);
pix3 = pixExpandReplicate(pix2, 6);
pixSaveTiled(pix3, pixa, 1, (i == 0), 20, 32);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pixDestroy(&pix1);
DisplayPix(&pixa, 100, 200, NULL);
/* Results better for pixScaleBySampling with + 0.5, for small,
* odd-dimension pix. */
pixa = pixaCreate(11);
pix1 = pixExpandReplicate(pixc, 2);
for (i = 0; i < 11; i++) {
scale = 0.30 + 0.035 * (l_float32)i;
pix2 = pixScaleBySampling(pix1, scale, scale);
pix3 = pixExpandReplicate(pix2, 6);
pixSaveTiled(pix3, pixa, 1, (i == 0), 20, 32);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pixDestroy(&pix1);
DisplayPix(&pixa, 100, 300, NULL);
/* Results same for pixRotateAM w/ and w/out + 0.5 */
pixa = pixaCreate(11);
pix1 = pixExpandReplicate(pixc, 1);
for (i = 0; i < 11; i++) {
angle = 0.10 + 0.05 * (l_float32)i;
pix2 = pixRotateAM(pix1, angle, L_BRING_IN_BLACK);
pix3 = pixExpandReplicate(pix2, 8);
pixSaveTiled(pix3, pixa, 1, (i == 0), 20, 32);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pixDestroy(&pix1);
DisplayPix(&pixa, 100, 400, NULL);
/* If the size is odd, we express the center exactly, and the
* results are better for pixRotateBySampling() w/out 0.5
* However, if the size is even, the center value is not
* exact, and if we choose it 0.5 smaller than the actual
* center, we get symmetrical results with +0.5.
* So we choose not to include + 0.5. */
pixa = pixaCreate(11);
pix1 = pixExpandReplicate(pixc, 1);
for (i = 0; i < 11; i++) {
angle = 0.10 + 0.05 * (l_float32)i;
pix2 = pixRotateBySampling(pix1, 4, 4, angle, L_BRING_IN_BLACK);
pix3 = pixExpandReplicate(pix2, 8);
pixSaveTiled(pix3, pixa, 1, (i == 0), 20, 32);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pixDestroy(&pix1);
DisplayPix(&pixa, 100, 500, NULL);
/* Results same for pixRotateAMCorner w/ and w/out + 0.5 */
pixa = pixaCreate(11);
pix1 = pixExpandReplicate(pixc, 1);
for (i = 0; i < 11; i++) {
angle = 0.10 + 0.05 * (l_float32)i;
pix2 = pixRotateAMCorner(pix1, angle, L_BRING_IN_BLACK);
pix3 = pixExpandReplicate(pix2, 8);
pixSaveTiled(pix3, pixa, 1, (i == 0), 20, 32);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pixDestroy(&pix1);
DisplayPix(&pixa, 100, 600, NULL);
/* Results better for pixRotateAMColorFast without + 0.5 */
pixa = pixaCreate(11);
pix1 = pixExpandReplicate(pixc, 1);
for (i = 0; i < 11; i++) {
angle = 0.10 + 0.05 * (l_float32)i;
pix2 = pixRotateAMColorFast(pix1, angle, 0);
pix3 = pixExpandReplicate(pix2, 8);
pixSaveTiled(pix3, pixa, 1, (i == 0), 20, 32);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pixDestroy(&pix1);
DisplayPix(&pixa, 100, 700, NULL);
/* Results slightly better for pixScaleColorLI() w/out + 0.5 */
pixa = pixaCreate(11);
pix1 = pixExpandReplicate(pixc, 1);
for (i = 0; i < 11; i++) {
scale = 1.0 + 0.2 * (l_float32)i;
pix2 = pixScaleColorLI(pix1, scale, scale);
pix3 = pixExpandReplicate(pix2, 4);
pixSaveTiled(pix3, pixa, 1, (i == 0), 20, 32);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pixDestroy(&pix1);
DisplayPix(&pixa, 100, 800, NULL);
/* Results slightly better for pixScaleColorLI() w/out + 0.5 */
pixa = pixaCreate(11);
pix1 = pixExpandReplicate(pixc, 1);
for (i = 0; i < 11; i++) {
scale = 1.0 + 0.2 * (l_float32)i;
pix2 = pixScaleLI(pix1, scale, scale);
pix3 = pixExpandReplicate(pix2, 4);
pixSaveTiled(pix3, pixa, 1, (i == 0), 20, 32);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pixDestroy(&pix1);
DisplayPix(&pixa, 100, 940, NULL);
pixDestroy(&pixc);
return 0;
}
/*!
* 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;
}
main(int argc,
char **argv)
{
l_int32 i, w, h, same;
char filename[][64] = {BINARY_IMAGE,
TWO_BPP_IMAGE_NO_CMAP, TWO_BPP_IMAGE_CMAP,
FOUR_BPP_IMAGE_NO_CMAP, FOUR_BPP_IMAGE_CMAP,
EIGHT_BPP_IMAGE_NO_CMAP, EIGHT_BPP_IMAGE_CMAP,
RGB_IMAGE};
BOX *box;
PIX *pix, *pixs, *pixt, *pixt1, *pixt2, *pixt3, *pixt4, *pixt5, *pixd;
static char mainName[] = "expand_reg";
if (argc != 1)
exit(ERROR_INT(" Syntax: expand_reg", mainName, 1));
pixDisplayWrite(NULL, -1);
for (i = 0; i < 8; i++) {
pixs = pixRead(filename[i]);
pixt = pixExpandReplicate(pixs, 2);
pixDisplayWrite(pixt, 1);
pixDestroy(&pixt);
pixt = pixExpandReplicate(pixs, 3);
pixDisplayWrite(pixt, 1);
pixDestroy(&pixt);
if (i == 4) {
pixt = pixScale(pixs, 3.0, 3.0);
pixWrite("/tmp/junkpixt.png", pixt, IFF_PNG);
pixDestroy(&pixt);
}
pixDestroy(&pixs);
}
pix = pixRead("test1.png");
pixGetDimensions(pix, &w, &h, NULL);
for (i = 1; i <= 15; i++) {
box = boxCreate(13 * i, 13 * i, w - 13 * i, h - 13 * i);
pixs = pixClipRectangle(pix, box, NULL);
pixt = pixExpandReplicate(pixs, 3);
pixDisplayWrite(pixt, 1);
boxDestroy(&box);
pixDestroy(&pixt);
pixDestroy(&pixs);
}
pixDestroy(&pix);
pixs = pixRead("speckle.png");
/* Test 2x expansion of 1 bpp */
pixt = pixExpandBinaryPower2(pixs, 2);
pixDisplayWrite(pixt, 1);
pixd = pixReduceRankBinary2(pixt, 4, NULL);
pixEqual(pixs, pixd, &same);
if (!same)
fprintf(stderr, "Error in 2x 1bpp expansion\n");
pixDestroy(&pixt);
pixDestroy(&pixd);
/* Test 2x expansion of 2 bpp */
pixt1 = pixConvert1To2(NULL, pixs, 3, 0);
pixt2 = pixExpandReplicate(pixt1, 2);
pixDisplayWrite(pixt2, 1);
pixt3 = pixConvertTo8(pixt2, FALSE);
pixt4 = pixThresholdToBinary(pixt3, 250);
pixd = pixReduceRankBinary2(pixt4, 4, NULL);
pixEqual(pixs, pixd, &same);
if (!same)
fprintf(stderr, "Error in 2x 2bpp expansion\n");
pixt5 = pixExpandBinaryPower2(pixd, 2);
pixDisplayWrite(pixt5, 1);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
pixDestroy(&pixt3);
pixDestroy(&pixt4);
pixDestroy(&pixt5);
pixDestroy(&pixd);
/* Test 4x expansion of 4 bpp */
pixt1 = pixConvert1To4(NULL, pixs, 15, 0);
pixt2 = pixExpandReplicate(pixt1, 4);
pixDisplayWrite(pixt2, 2);
pixt3 = pixConvertTo8(pixt2, FALSE);
pixt4 = pixThresholdToBinary(pixt3, 250);
pixDisplayWrite(pixt4, 2);
pixd = pixReduceRankBinaryCascade(pixt4, 4, 4, 0, 0);
pixEqual(pixs, pixd, &same);
if (!same)
fprintf(stderr, "Error in 4x 4bpp expansion\n");
pixDestroy(&pixt1);
pixDestroy(&pixt2);
pixDestroy(&pixt3);
pixDestroy(&pixt4);
pixDestroy(&pixd);
/* Test 8x expansion of 8 bpp */
pixt1 = pixConvertTo8(pixs, FALSE);
pixt2 = pixExpandReplicate(pixt1, 8);
pixDisplayWrite(pixt2, 4);
pixt3 = pixThresholdToBinary(pixt2, 250);
pixDisplayWrite(pixt3, 4);
pixd = pixReduceRankBinaryCascade(pixt3, 4, 4, 4, 0);
pixEqual(pixs, pixd, &same);
if (!same)
fprintf(stderr, "Error in 4x 4bpp expansion\n");
pixDestroy(&pixt1);
pixDestroy(&pixt2);
pixDestroy(&pixt3);
pixDestroy(&pixd);
pixDestroy(&pixs);
pixDisplayMultiple("/tmp/junk_write_display*");
return 0;
}
main(int argc,
char **argv)
{
l_int32 i, j, w, h, error;
l_float32 val1, val2;
l_float32 val00, val10, val01, val11, valc00, valc10, valc01, valc11;
PIX *pixs, *pixg, *pixt1, *pixt2, *pixt3, *pixt4, *pixt5;
FPIXA *fpixam, *fpixav, *fpixarv;
BOXAA *baa;
static char mainName[] = "quadtreetest";
if (argc != 1)
return ERROR_INT(" Syntax: quadtreetest", mainName, 1);
/* Test generation of quadtree regions. */
baa = boxaaQuadtreeRegions(1000, 500, 3);
boxaaWriteStream(stderr, baa);
boxaaDestroy(&baa);
baa = boxaaQuadtreeRegions(1001, 501, 3);
boxaaWriteStream(stderr, baa);
boxaaDestroy(&baa);
/* Test quadtree stats generation */
#if 1
pixs = pixRead("rabi.png");
pixg = pixScaleToGray4(pixs);
#else
pixs = pixRead("test24.jpg");
pixg = pixConvertTo8(pixs, 0);
#endif
pixQuadtreeMean(pixg, 8, NULL, &fpixam);
pixt1 = fpixaDisplayQuadtree(fpixam, 4);
pixDisplay(pixt1, 100, 0);
pixWrite("/tmp/quadtree1.png", pixt1, IFF_PNG);
pixQuadtreeVariance(pixg, 8, NULL, NULL, &fpixav, &fpixarv);
pixt2 = fpixaDisplayQuadtree(fpixav, 4);
pixDisplay(pixt2, 100, 200);
pixWrite("/tmp/quadtree2.png", pixt2, IFF_PNG);
pixt3 = fpixaDisplayQuadtree(fpixarv, 4);
pixDisplay(pixt3, 100, 400);
pixWrite("/tmp/quadtree3.png", pixt3, IFF_PNG);
/* Compare with fixed-size tiling at a resolution corresponding
* to the deepest level of the quadtree above */
pixt4 = pixGetAverageTiled(pixg, 5, 6, L_MEAN_ABSVAL);
pixt5 = pixExpandReplicate(pixt4, 4);
pixWrite("/tmp/quadtree4.png", pixt5, IFF_PNG);
pixDisplay(pixt5, 800, 0);
pixDestroy(&pixt4);
pixDestroy(&pixt5);
pixt4 = pixGetAverageTiled(pixg, 5, 6, L_STANDARD_DEVIATION);
pixt5 = pixExpandReplicate(pixt4, 4);
pixWrite("/tmp/quadtree5.png", pixt5, IFF_PNG);
pixDisplay(pixt5, 800, 400);
/* Test quadtree parent/child access */
error = FALSE;
fpixaGetFPixDimensions(fpixam, 4, &w, &h);
for (i = 0; i < w; i += 2) {
for (j = 0; j < h; j += 2) {
quadtreeGetParent(fpixam, 4, j, i, &val1);
fpixaGetPixel(fpixam, 3, j / 2, i / 2, &val2);
if (val1 != val2) error = TRUE;
}
}
if (error)
fprintf(stderr, "\n======================\nError: parent access\n");
else
fprintf(stderr, "\n======================\nSuccess: parent access\n");
error = FALSE;
for (i = 0; i < w; i++) {
for (j = 0; j < h; j++) {
quadtreeGetChildren(fpixam, 4, j, i,
&val00, &val10, &val01, &val11);
fpixaGetPixel(fpixam, 5, 2 * j, 2 * i, &valc00);
fpixaGetPixel(fpixam, 5, 2 * j + 1, 2 * i, &valc10);
fpixaGetPixel(fpixam, 5, 2 * j, 2 * i + 1, &valc01);
fpixaGetPixel(fpixam, 5, 2 * j + 1, 2 * i + 1, &valc11);
if ((val00 != valc00) || (val10 != valc10) ||
(val01 != valc01) || (val11 != valc11))
error = TRUE;
}
}
if (error)
fprintf(stderr, "Error: child access\n======================\n");
else
fprintf(stderr, "Success: child access\n======================\n");
pixDestroy(&pixs);
pixDestroy(&pixg);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
pixDestroy(&pixt3);
pixDestroy(&pixt4);
pixDestroy(&pixt5);
fpixaDestroy(&fpixam);
fpixaDestroy(&fpixav);
fpixaDestroy(&fpixarv);
return 0;
}
/*!
* \brief pixMorphCompSequenceDwa()
*
* \param[in] pixs
* \param[in] sequence string specifying sequence
* \param[in] dispsep controls debug display of each result in the sequence:
* 0: no output
* > 0: gives horizontal separation in pixels between
* successive displays
* < 0: pdf output; abs(dispsep) is used for naming
* \return pixd, or NULL on error
*
* <pre>
* Notes:
* (1) This does dwa morphology on binary images, using brick Sels.
* (2) This runs a pipeline of operations; no branching is allowed.
* (3) It implements all brick Sels that have dimensions up to 63
* on each side, using a composite (linear + comb) when useful.
* (4) A new image is always produced; the input image is not changed.
* (5) This contains an interpreter, allowing sequences to be
* generated and run.
* (6) See pixMorphSequence() for further information about usage.
* </pre>
*/
PIX *
pixMorphCompSequenceDwa(PIX *pixs,
const char *sequence,
l_int32 dispsep)
{
char *rawop, *op, *fname;
char buf[256];
l_int32 nops, i, j, nred, fact, w, h, x, y, border, pdfout;
l_int32 level[4];
PIX *pixt1, *pixt2;
PIXA *pixa;
SARRAY *sa;
PROCNAME("pixMorphCompSequenceDwa");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (!sequence)
return (PIX *)ERROR_PTR("sequence not defined", procName, NULL);
/* Split sequence into individual operations */
sa = sarrayCreate(0);
sarraySplitString(sa, sequence, "+");
nops = sarrayGetCount(sa);
pdfout = (dispsep < 0) ? 1 : 0;
if (!morphSequenceVerify(sa)) {
sarrayDestroy(&sa);
return (PIX *)ERROR_PTR("sequence not valid", procName, NULL);
}
/* Parse and operate */
pixa = NULL;
if (pdfout) {
pixa = pixaCreate(0);
pixaAddPix(pixa, pixs, L_CLONE);
snprintf(buf, sizeof(buf), "/tmp/seq_output_%d.pdf", L_ABS(dispsep));
fname = genPathname(buf, NULL);
}
border = 0;
pixt1 = pixCopy(NULL, pixs);
pixt2 = NULL;
x = y = 0;
for (i = 0; i < nops; i++) {
rawop = sarrayGetString(sa, i, L_NOCOPY);
op = stringRemoveChars(rawop, " \n\t");
switch (op[0])
{
case 'd':
case 'D':
sscanf(&op[1], "%d.%d", &w, &h);
pixt2 = pixDilateCompBrickDwa(NULL, pixt1, w, h);
pixSwapAndDestroy(&pixt1, &pixt2);
break;
case 'e':
case 'E':
sscanf(&op[1], "%d.%d", &w, &h);
pixt2 = pixErodeCompBrickDwa(NULL, pixt1, w, h);
pixSwapAndDestroy(&pixt1, &pixt2);
break;
case 'o':
case 'O':
sscanf(&op[1], "%d.%d", &w, &h);
pixOpenCompBrickDwa(pixt1, pixt1, w, h);
break;
case 'c':
case 'C':
sscanf(&op[1], "%d.%d", &w, &h);
pixCloseCompBrickDwa(pixt1, pixt1, w, h);
break;
case 'r':
case 'R':
nred = strlen(op) - 1;
for (j = 0; j < nred; j++)
level[j] = op[j + 1] - '0';
for (j = nred; j < 4; j++)
level[j] = 0;
pixt2 = pixReduceRankBinaryCascade(pixt1, level[0], level[1],
level[2], level[3]);
pixSwapAndDestroy(&pixt1, &pixt2);
break;
case 'x':
case 'X':
sscanf(&op[1], "%d", &fact);
pixt2 = pixExpandReplicate(pixt1, fact);
pixSwapAndDestroy(&pixt1, &pixt2);
break;
case 'b':
case 'B':
sscanf(&op[1], "%d", &border);
pixt2 = pixAddBorder(pixt1, border, 0);
pixSwapAndDestroy(&pixt1, &pixt2);
break;
default:
/* All invalid ops are caught in the first pass */
break;
}
LEPT_FREE(op);
/* Debug output */
if (dispsep > 0) {
pixDisplay(pixt1, x, y);
x += dispsep;
}
if (pdfout)
pixaAddPix(pixa, pixt1, L_COPY);
}
if (border > 0) {
pixt2 = pixRemoveBorder(pixt1, border);
pixSwapAndDestroy(&pixt1, &pixt2);
}
if (pdfout) {
pixaConvertToPdf(pixa, 0, 1.0, L_FLATE_ENCODE, 0, fname, fname);
LEPT_FREE(fname);
pixaDestroy(&pixa);
}
sarrayDestroy(&sa);
return pixt1;
}
// Finds image regions within the source pix (page image) and returns
// the image regions as a Boxa, Pixa pair, analgous to pixConnComp.
// The returned boxa, pixa may be NULL, meaning no images found.
// If not NULL, they must be destroyed by the caller.
void ImageFinder::FindImages(Pix* pix, Boxa** boxa, Pixa** pixa) {
*boxa = NULL;
*pixa = NULL;
#ifdef HAVE_LIBLEPT
if (pixGetWidth(pix) < kMinImageFindSize ||
pixGetHeight(pix) < kMinImageFindSize)
return; // Not worth looking at small images.
// Reduce by factor 2.
Pix *pixr = pixReduceRankBinaryCascade(pix, 1, 0, 0, 0);
pixDisplayWrite(pixr, textord_tabfind_show_images);
// Get the halftone mask directly from Leptonica.
Pix *pixht2 = pixGenHalftoneMask(pixr, NULL, NULL,
textord_tabfind_show_images);
pixDestroy(&pixr);
if (pixht2 == NULL)
return;
// Expand back up again.
Pix *pixht = pixExpandReplicate(pixht2, 2);
pixDisplayWrite(pixht, textord_tabfind_show_images);
pixDestroy(&pixht2);
// Fill to capture pixels near the mask edges that were missed
Pix *pixt = pixSeedfillBinary(NULL, pixht, pix, 8);
pixOr(pixht, pixht, pixt);
pixDestroy(&pixt);
// Eliminate lines and bars that may be joined to images.
Pix* pixfinemask = pixReduceRankBinaryCascade(pixht, 1, 1, 3, 3);
pixDilateBrick(pixfinemask, pixfinemask, 5, 5);
pixDisplayWrite(pixfinemask, textord_tabfind_show_images);
Pix* pixreduced = pixReduceRankBinaryCascade(pixht, 1, 1, 1, 1);
Pix* pixreduced2 = pixReduceRankBinaryCascade(pixreduced, 3, 3, 3, 0);
pixDestroy(&pixreduced);
pixDilateBrick(pixreduced2, pixreduced2, 5, 5);
Pix* pixcoarsemask = pixExpandReplicate(pixreduced2, 8);
pixDestroy(&pixreduced2);
pixDisplayWrite(pixcoarsemask, textord_tabfind_show_images);
// Combine the coarse and fine image masks.
pixAnd(pixcoarsemask, pixcoarsemask, pixfinemask);
pixDestroy(&pixfinemask);
// Dilate a bit to make sure we get everything.
pixDilateBrick(pixcoarsemask, pixcoarsemask, 3, 3);
Pix* pixmask = pixExpandReplicate(pixcoarsemask, 16);
pixDestroy(&pixcoarsemask);
pixDisplayWrite(pixmask, textord_tabfind_show_images);
// And the image mask with the line and bar remover.
pixAnd(pixht, pixht, pixmask);
pixDestroy(&pixmask);
pixDisplayWrite(pixht, textord_tabfind_show_images);
// Find the individual image regions in the mask image.
*boxa = pixConnComp(pixht, pixa, 8);
pixDestroy(&pixht);
// Rectangularize the individual images. If a sharp edge in vertical and/or
// horizontal occupancy can be found, it indicates a probably rectangular
// image with unwanted bits merged on, so clip to the approximate rectangle.
int npixes = pixaGetCount(*pixa);
for (int i = 0; i < npixes; ++i) {
int x_start, x_end, y_start, y_end;
Pix* img_pix = pixaGetPix(*pixa, i, L_CLONE);
pixDisplayWrite(img_pix, textord_tabfind_show_images);
if (pixNearlyRectangular(img_pix, kMinRectangularFraction,
kMaxRectangularFraction,
kMaxRectangularGradient,
&x_start, &y_start, &x_end, &y_end)) {
// Add 1 to the size as a kludgy flag to indicate to the later stages
// of processing that it is a clipped rectangular image .
Pix* simple_pix = pixCreate(pixGetWidth(img_pix) + 1,
pixGetHeight(img_pix), 1);
pixDestroy(&img_pix);
pixRasterop(simple_pix, x_start, y_start, x_end - x_start,
y_end - y_start, PIX_SET, NULL, 0, 0);
// pixaReplacePix takes ownership of the simple_pix.
pixaReplacePix(*pixa, i, simple_pix, NULL);
img_pix = pixaGetPix(*pixa, i, L_CLONE);
}
// Subtract the pix from the correct location in the master image.
l_int32 x, y, width, height;
pixDisplayWrite(img_pix, textord_tabfind_show_images);
boxaGetBoxGeometry(*boxa, i, &x, &y, &width, &height);
pixRasterop(pix, x, y, width, height, PIX_NOT(PIX_SRC) & PIX_DST,
img_pix, 0, 0);
pixDestroy(&img_pix);
}
#endif
}
