/*!
* dewarpApplyDisparity()
*
* Input: dew
* pixs (image to be modified; can be 1, 8 or 32 bpp)
* debugflag
* Return: 0 if OK, 1 on error
*
* Notes:
* (1) This applies the vertical disparity array to the specified
* image. For src pixels above the image, we use the pixels
* in the first raster line.
* (2) This works with stripped models. If the full resolution
* disparity array(s) are missing, they are remade.
*/
l_int32
dewarpApplyDisparity(L_DEWARP *dew,
PIX *pixs,
l_int32 debugflag)
{
PIX *pixv, *pixd;
PROCNAME("dewarpApplyDisparity");
if (!dew)
return ERROR_INT("dew not defined", procName, 1);
if (dew->success == 0)
return ERROR_INT("model failed to build", procName, 1);
if (!pixs)
return ERROR_INT("pixs not defined", procName, 1);
/* Generate the full res disparity arrays if they don't exist;
* e.g., if they've been minimized or read from file. */
dewarpPopulateFullRes(dew);
pixDestroy(&dew->pixd); /* remove any previous one */
if ((pixv = pixApplyVerticalDisparity(pixs, dew->fullvdispar)) == NULL)
return ERROR_INT("pixv not made", procName, 1);
if (debugflag) {
pixDisplayWithTitle(pixv, 300, 0, "pixv", 1);
pixWriteTempfile("/tmp", "pixv.png", pixv, IFF_PNG, NULL);
}
if (dew->applyhoriz) {
if ((pixd = pixApplyHorizontalDisparity(pixv, dew->fullhdispar,
dew->extraw)) == NULL)
return ERROR_INT("pixd not made", procName, 1);
pixDestroy(&pixv);
dew->pixd = pixd;
if (debugflag) {
pixDisplayWithTitle(pixd, 600, 0, "pixd", 1);
pixWriteTempfile("/tmp", "pixd.png", pixd, IFF_PNG, NULL);
}
}
else
dew->pixd = pixv;
return 0;
}
/*!
* selaAddTJunctions()
*
* Input: sela (<optional>)
* hlsize (length of each line of hits from origin)
* mdist (distance of misses from the origin)
* norient (number of orientations; max of 8)
* debugflag (1 for debug output)
* Return: sela with additional sels, or null on error
*
* Notes:
* (1) Adds hitmiss Sels for the T-junction of two lines.
* If the lines are very thin, they must be nearly orthogonal
* to register.
* (2) The number of Sels generated is 4 * @norient.
* (3) It is suggested that @hlsize be chosen at least 1 greater
* than @mdist. Try values of (@hlsize, @mdist) such as
* (6,5), (7,6), (8,7), (9,7), etc.
*/
SELA *
selaAddTJunctions(SELA *sela,
l_float32 hlsize,
l_float32 mdist,
l_int32 norient,
l_int32 debugflag)
{
char name[L_BUF_SIZE];
l_int32 i, j, k, w, xc, yc;
l_float64 pi, halfpi, radincr, jang, radang;
l_float64 angle[3], dist[3];
PIX *pixc, *pixm, *pixt;
PIXA *pixa;
PTA *pta1, *pta2, *pta3;
SEL *sel;
PROCNAME("selaAddTJunctions");
if (hlsize <= 2)
return (SELA *)ERROR_PTR("hlsizel not > 1", procName, NULL);
if (norient < 1 || norient > 8)
return (SELA *)ERROR_PTR("norient not in [1, ... 8]", procName, NULL);
if (!sela) {
if ((sela = selaCreate(0)) == NULL)
return (SELA *)ERROR_PTR("sela not made", procName, NULL);
}
pi = 3.1415926535;
halfpi = 3.1415926535 / 2.0;
radincr = halfpi / (l_float32)norient;
w = (l_int32)(2.4 * (L_MAX(hlsize, mdist) + 0.5));
if (w % 2 == 0)
w++;
xc = w / 2;
yc = w / 2;
pixa = pixaCreate(4 * norient);
for (i = 0; i < norient; i++) {
for (j = 0; j < 4; j++) { /* 4 orthogonal orientations */
jang = (l_float32)j * halfpi;
/* Set the don't cares */
pixc = pixCreate(w, w, 32);
pixSetAll(pixc);
/* Add the green lines of hits */
pixm = pixCreate(w, w, 1);
radang = (l_float32)i * radincr;
pta1 = generatePtaLineFromPt(xc, yc, hlsize + 1, jang + radang);
pta2 = generatePtaLineFromPt(xc, yc, hlsize + 1,
jang + radang + halfpi);
pta3 = generatePtaLineFromPt(xc, yc, hlsize + 1,
jang + radang + pi);
ptaJoin(pta1, pta2, 0, -1);
ptaJoin(pta1, pta3, 0, -1);
pixRenderPta(pixm, pta1, L_SET_PIXELS);
pixPaintThroughMask(pixc, pixm, 0, 0, 0x00ff0000);
ptaDestroy(&pta1);
ptaDestroy(&pta2);
ptaDestroy(&pta3);
/* Add red misses between the lines */
angle[0] = radang + jang - halfpi;
angle[1] = radang + jang + 0.5 * halfpi;
angle[2] = radang + jang + 1.5 * halfpi;
dist[0] = 0.8 * mdist;
dist[1] = dist[2] = mdist;
for (k = 0; k < 3; k++) {
pixSetPixel(pixc, xc + (l_int32)(dist[k] * cos(angle[k])),
yc + (l_int32)(dist[k] * sin(angle[k])),
0xff000000);
}
/* Add dark green for origin */
pixSetPixel(pixc, xc, yc, 0x00550000);
/* Generate the sel */
sel = selCreateFromColorPix(pixc, NULL);
sprintf(name, "sel_cross_%d", 4 * i + j);
selaAddSel(sela, sel, name, 0);
if (debugflag) {
pixt = pixScaleBySampling(pixc, 10.0, 10.0);
pixaAddPix(pixa, pixt, L_INSERT);
}
pixDestroy(&pixm);
pixDestroy(&pixc);
}
}
if (debugflag) {
l_int32 w;
pixaGetPixDimensions(pixa, 0, &w, NULL, NULL);
pixt = pixaDisplayTiledAndScaled(pixa, 32, w, 4, 0, 10, 2);
pixWriteTempfile("/tmp", "tsel1.png", pixt, IFF_PNG, 0);
pixDisplay(pixt, 0, 100);
pixDestroy(&pixt);
pixt = selaDisplayInPix(sela, 15, 2, 20, 4);
pixWriteTempfile("/tmp", "tsel2.png", pixt, IFF_PNG, 0);
pixDisplay(pixt, 500, 100);
pixDestroy(&pixt);
selaWriteStream(stderr, sela);
}
pixaDestroy(&pixa);
return sela;
}
/*!
* dewarpBuildModel()
*
* Input: dew
* debugflag (1 for debugging output)
* Return: 0 if OK, 1 on error
*
* Notes:
* (1) This is the basic function that builds the vertical
* disparity array, which allows determination of the
* src pixel in the input image corresponding to each
* dest pixel in the dewarped image.
* (2) The method is as follows:
* * Estimate the centers of all the long textlines and
* fit a LS quadratic to each one. This smooths the curves.
* * Sample each curve at a regular interval, find the y-value
* of the flat point on each curve, and subtract the sampled
* curve value from this value. This is the vertical
* disparity.
* * Fit a LS quadratic to each set of vertically aligned
* disparity samples. This smooths the disparity values
* in the vertical direction. Then resample at the same
* regular interval, We now have a regular grid of smoothed
* vertical disparity valuels.
* * Interpolate this grid to get a full resolution disparity
* map. This can be applied directly to the src image
* pixels to dewarp the image in the vertical direction,
* making all textlines horizontal.
*/
l_int32
dewarpBuildModel(L_DEWARP *dew,
l_int32 debugflag)
{
char *tempname;
l_int32 i, j, nlines, nx, ny, sampling;
l_float32 c0, c1, c2, x, y, flaty, val;
l_float32 *faflats;
NUMA *nax, *nafit, *nacurve, *nacurves, *naflat, *naflats, *naflatsi;
PIX *pixs, *pixt1, *pixt2;
PTA *pta, *ptad;
PTAA *ptaa1, *ptaa2, *ptaa3, *ptaa4, *ptaa5, *ptaa6, *ptaa7;
FPIX *fpix1, *fpix2, *fpix3;
PROCNAME("dewarpBuildModel");
if (!dew)
return ERROR_INT("dew not defined", procName, 1);
pixs = dew->pixs;
if (debugflag) {
pixDisplayWithTitle(pixs, 0, 0, "pixs", 1);
pixWriteTempfile("/tmp", "pixs.png", pixs, IFF_PNG, NULL);
}
/* Make initial estimate of centers of textlines */
ptaa1 = pixGetTextlineCenters(pixs, DEBUG_TEXTLINE_CENTERS);
if (debugflag) {
pixt1 = pixConvertTo32(pixs);
pixt2 = pixDisplayPtaa(pixt1, ptaa1);
pixWriteTempfile("/tmp", "lines1.png", pixt2, IFF_PNG, NULL);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
}
/* Remove all lines that are not near the length
* of the longest line. */
ptaa2 = ptaaRemoveShortLines(pixs, ptaa1, 0.8, DEBUG_SHORT_LINES);
if (debugflag) {
pixt1 = pixConvertTo32(pixs);
pixt2 = pixDisplayPtaa(pixt1, ptaa2);
pixWriteTempfile("/tmp", "lines2.png", pixt2, IFF_PNG, NULL);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
}
nlines = ptaaGetCount(ptaa2);
if (nlines < dew->minlines)
return ERROR_INT("insufficient lines to build model", procName, 1);
/* Do quadratic fit to smooth each line. A single quadratic
* over the entire width of the line appears to be sufficient.
* Quartics tend to overfit to noise. Each line is thus
* represented by three coefficients: c2 * x^2 + c1 * x + c0.
* Using the coefficients, sample each fitted curve uniformly
* across the full width of the image. */
sampling = dew->sampling;
nx = dew->nx;
ny = dew->ny;
ptaa3 = ptaaCreate(nlines);
nacurve = numaCreate(nlines); /* stores curvature coeff c2 */
for (i = 0; i < nlines; i++) { /* for each line */
pta = ptaaGetPta(ptaa2, i, L_CLONE);
ptaGetQuadraticLSF(pta, &c2, &c1, &c0, NULL);
numaAddNumber(nacurve, c2);
ptad = ptaCreate(nx);
for (j = 0; j < nx; j++) { /* uniformly sampled in x */
x = j * sampling;
applyQuadraticFit(c2, c1, c0, x, &y);
ptaAddPt(ptad, x, y);
}
ptaaAddPta(ptaa3, ptad, L_INSERT);
ptaDestroy(&pta);
}
if (debugflag) {
ptaa4 = ptaaCreate(nlines);
for (i = 0; i < nlines; i++) {
pta = ptaaGetPta(ptaa2, i, L_CLONE);
ptaGetArrays(pta, &nax, NULL);
ptaGetQuadraticLSF(pta, NULL, NULL, NULL, &nafit);
ptad = ptaCreateFromNuma(nax, nafit);
ptaaAddPta(ptaa4, ptad, L_INSERT);
ptaDestroy(&pta);
numaDestroy(&nax);
numaDestroy(&nafit);
}
pixt1 = pixConvertTo32(pixs);
pixt2 = pixDisplayPtaa(pixt1, ptaa4);
pixWriteTempfile("/tmp", "lines3.png", pixt2, IFF_PNG, NULL);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
ptaaDestroy(&ptaa4);
}
/* Find and save the flat points in each curve. */
naflat = numaCreate(nlines);
for (i = 0; i < nlines; i++) {
pta = ptaaGetPta(ptaa3, i, L_CLONE);
numaGetFValue(nacurve, i, &c2);
if (c2 <= 0) /* flat point at bottom; max value of y in curve */
ptaGetRange(pta, NULL, NULL, NULL, &flaty);
else /* flat point at top; min value of y in curve */
ptaGetRange(pta, NULL, NULL, &flaty, NULL);
numaAddNumber(naflat, flaty);
ptaDestroy(&pta);
}
/* Sort the lines in ptaa3 by their position */
naflatsi = numaGetSortIndex(naflat, L_SORT_INCREASING);
naflats = numaSortByIndex(naflat, naflatsi);
nacurves = numaSortByIndex(nacurve, naflatsi);
dew->naflats = naflats;
dew->nacurves = nacurves;
ptaa4 = ptaaSortByIndex(ptaa3, naflatsi);
numaDestroy(&naflat);
numaDestroy(&nacurve);
numaDestroy(&naflatsi);
if (debugflag) {
tempname = genTempFilename("/tmp", "naflats.na", 0);
numaWrite(tempname, naflats);
FREE(tempname);
}
/* Convert the sampled points in ptaa3 to a sampled disparity with
* with respect to the flat point in the curve. */
ptaa5 = ptaaCreate(nlines);
for (i = 0; i < nlines; i++) {
pta = ptaaGetPta(ptaa4, i, L_CLONE);
numaGetFValue(naflats, i, &flaty);
ptad = ptaCreate(nx);
for (j = 0; j < nx; j++) {
ptaGetPt(pta, j, &x, &y);
ptaAddPt(ptad, x, flaty - y);
}
ptaaAddPta(ptaa5, ptad, L_INSERT);
ptaDestroy(&pta);
}
if (debugflag) {
tempname = genTempFilename("/tmp", "ptaa5.ptaa", 0);
ptaaWrite(tempname, ptaa5, 0);
FREE(tempname);
}
/* Generate a ptaa taking vertical 'columns' from ptaa5.
* We want to fit the vertical disparity on the column to the
* vertical position of the line, which we call 'y' here and
* obtain from naflats. */
ptaa6 = ptaaCreate(nx);
faflats = numaGetFArray(naflats, L_NOCOPY);
for (j = 0; j < nx; j++) {
pta = ptaCreate(nlines);
for (i = 0; i < nlines; i++) {
y = faflats[i];
ptaaGetPt(ptaa5, i, j, NULL, &val); /* disparity value */
ptaAddPt(pta, y, val);
}
ptaaAddPta(ptaa6, pta, L_INSERT);
}
if (debugflag) {
tempname = genTempFilename("/tmp", "ptaa6.ptaa", 0);
ptaaWrite(tempname, ptaa6, 0);
FREE(tempname);
}
/* Do quadratic fit vertically on a subset of pixel columns
* for the vertical displacement, which identifies the
* src pixel(s) for each dest pixel. Sample the displacement
* on a regular grid in the vertical direction. */
ptaa7 = ptaaCreate(nx); /* uniformly sampled across full height of image */
for (j = 0; j < nx; j++) { /* for each column */
pta = ptaaGetPta(ptaa6, j, L_CLONE);
ptaGetQuadraticLSF(pta, &c2, &c1, &c0, NULL);
ptad = ptaCreate(ny);
for (i = 0; i < ny; i++) { /* uniformly sampled in y */
y = i * sampling;
applyQuadraticFit(c2, c1, c0, y, &val);
ptaAddPt(ptad, y, val);
}
ptaaAddPta(ptaa7, ptad, L_INSERT);
ptaDestroy(&pta);
}
if (debugflag) {
tempname = genTempFilename("/tmp", "ptaa7.ptaa", 0);
ptaaWrite(tempname, ptaa7, 0);
FREE(tempname);
}
/* Save the result in a fpix at the specified subsampling */
fpix1 = fpixCreate(nx, ny);
for (i = 0; i < ny; i++) {
for (j = 0; j < nx; j++) {
ptaaGetPt(ptaa7, j, i, NULL, &val);
fpixSetPixel(fpix1, j, i, val);
}
}
dew->sampvdispar = fpix1;
/* Generate a full res fpix for vertical dewarping. We require that
* the size of this fpix is at least as big as the input image. */
fpix2 = fpixScaleByInteger(fpix1, sampling);
dew->fullvdispar = fpix2;
if (debugflag) {
pixt1 = fpixRenderContours(fpix2, -2., 2.0, 0.2);
pixWriteTempfile("/tmp", "vert-contours.png", pixt1, IFF_PNG, NULL);
pixDisplay(pixt1, 1000, 0);
pixDestroy(&pixt1);
}
/* Generate full res and sampled fpix for horizontal dewarping. This
* works to the extent that the line curvature is due to bending
* out of the plane normal to the camera, and not wide-angle
* "fishbowl" distortion. Also generate the sampled horizontal
* disparity array. */
if (dew->applyhoriz) {
fpix3 = fpixBuildHorizontalDisparity(fpix2, 0, &dew->extraw);
dew->fullhdispar = fpix3;
dew->samphdispar = fpixSampledDisparity(fpix3, dew->sampling);
if (debugflag) {
pixt1 = fpixRenderContours(fpix3, -2., 2.0, 0.2);
pixWriteTempfile("/tmp", "horiz-contours.png", pixt1,
IFF_PNG, NULL);
pixDisplay(pixt1, 1000, 0);
pixDestroy(&pixt1);
}
}
dew->success = 1;
ptaaDestroy(&ptaa1);
ptaaDestroy(&ptaa2);
ptaaDestroy(&ptaa3);
ptaaDestroy(&ptaa4);
ptaaDestroy(&ptaa5);
ptaaDestroy(&ptaa6);
ptaaDestroy(&ptaa7);
return 0;
}