/*!
* fpixBuildHorizontalDisparity()
*
* Input: fpixv (vertical disparity model)
* factor (conversion factor for vertical disparity slope;
* use 0 for default)
* &extraw (<return> extra width to be added to dewarped pix)
* Return: fpixh, or null on error
*
* Notes:
* (1) This takes the difference in vertical disparity at top
* and bottom of the image, and converts it to an assumed
* horizontal disparity.
*/
FPIX *
fpixBuildHorizontalDisparity(FPIX *fpixv,
l_float32 factor,
l_int32 *pextraw)
{
l_int32 w, h, i, j, fw, wpl, maxloc;
l_float32 val1, val2, vdisp, vdisp0, maxval;
l_float32 *data, *line, *fadiff;
NUMA *nadiff;
FPIX *fpixh;
PROCNAME("fpixBuildHorizontalDisparity");
if (!fpixv)
return (FPIX *)ERROR_PTR("fpixv not defined", procName, NULL);
if (!pextraw)
return (FPIX *)ERROR_PTR("&extraw not defined", procName, NULL);
if (factor == 0.0)
factor = DEFAULT_SLOPE_FACTOR;
/* Estimate horizontal disparity from the vertical disparity
* difference between the top and bottom, normalized to the
* image height. Add the maximum value to the width of the
* output image, so that all src pixels can be mapped
* into the dest. */
fpixGetDimensions(fpixv, &w, &h);
nadiff = numaCreate(w);
for (j = 0; j < w; j++) {
fpixGetPixel(fpixv, j, 0, &val1);
fpixGetPixel(fpixv, j, h - 1, &val2);
vdisp = factor * (val2 - val1) / (l_float32)h;
if (j == 0) vdisp0 = vdisp;
vdisp = vdisp0 - vdisp;
numaAddNumber(nadiff, vdisp);
}
numaGetMax(nadiff, &maxval, &maxloc);
*pextraw = (l_int32)(maxval + 0.5);
fw = w + *pextraw;
fpixh = fpixCreate(fw, h);
data = fpixGetData(fpixh);
wpl = fpixGetWpl(fpixh);
fadiff = numaGetFArray(nadiff, L_NOCOPY);
for (i = 0; i < h; i++) {
line = data + i * wpl;
for (j = 0; j < fw; j++) {
if (j < maxloc) /* this may not work for even pages */
line[j] = fadiff[j];
else /* keep it at the max value the rest of the way across */
line[j] = maxval;
}
}
numaDestroy(&nadiff);
return fpixh;
}
/*!
* fpixPrintStream()
*
* Input: stream
* fpix
* factor (subsampled)
* Return: 0 if OK, 1 on error
*
* Notes:
* (1) Subsampled printout of fpix for debugging.
*/
l_int32
fpixPrintStream(FILE *fp,
FPIX *fpix,
l_int32 factor)
{
l_int32 i, j, w, h, count;
l_float32 val;
PROCNAME("fpixPrintStream");
if (!fp)
return ERROR_INT("stream not defined", procName, 1);
if (!fpix)
return ERROR_INT("fpix not defined", procName, 1);
if (factor < 1)
return ERROR_INT("sampling factor < 1f", procName, 1);
fpixGetDimensions(fpix, &w, &h);
fprintf(fp, "\nFPix: w = %d, h = %d\n", w, h);
for (i = 0; i < h; i += factor) {
for (count = 0, j = 0; j < w; j += factor, count++) {
fpixGetPixel(fpix, j, i, &val);
fprintf(fp, "val[%d, %d] = %f ", i, j, val);
if ((count + 1) % 3 == 0) fprintf(fp, "\n");
}
if (count % 3) fprintf(fp, "\n");
}
fprintf(fp, "\n");
return 0;
}
/*!
* fpixSampledDisparity()
*
* Input: fpixs (full resolution disparity model)
* sampling (sampling factor)
* Return: fpixd (sampled disparity model), or null on error
*
* Notes:
* (1) This converts full to sampled disparity.
* (2) The input array is sampled at the right and top edges, and
* at every @sampling pixels horizontally and vertically.
* (3) The sampled array may not extend to the right and bottom
* pixels in fpixs. This will occur if fpixs was generated
* with slope extension because the image on that page was
* larger than normal. This is fine, because in use the
* sampled array will be interpolated back to full resolution
* and then extended as required. So the operations of
* sampling and interpolation will be idempotent.
* (4) There must be at least 3 sampled points horizontally and
* vertically.
*/
static FPIX *
fpixSampledDisparity(FPIX *fpixs,
l_int32 sampling)
{
l_int32 w, h, wd, hd, i, j, is, js;
l_float32 val;
FPIX *fpixd;
PROCNAME("fpixSampledDisparity");
if (!fpixs)
return (FPIX *)ERROR_PTR("fpixs not defined", procName, NULL);
if (sampling < 1)
return (FPIX *)ERROR_PTR("sampling < 1", procName, NULL);
fpixGetDimensions(fpixs, &w, &h);
wd = 1 + (w + sampling - 2) / sampling;
hd = 1 + (h + sampling - 2) / sampling;
if (wd < 3 || hd < 3)
return (FPIX *)ERROR_PTR("wd < 3 or hd < 3", procName, NULL);
fpixd = fpixCreate(wd, hd);
for (i = 0; i < hd; i++) {
is = sampling * i;
if (is >= h) continue;
for (j = 0; j < wd; j++) {
js = sampling * j;
if (js >= w) continue;
fpixGetPixel(fpixs, js, is, &val);
fpixSetPixel(fpixd, j, i, val);
}
}
return fpixd;
}
/*!
* fpixSampledDisparity()
*
* Input: fpixs (full resolution disparity model)
* sampling (sampling factor)
* Return: fpixd (sampled disparity model), or null on error
*
* Notes:
* (1) The input array is sampled at the right and top edges, and
* at every @sampling pixels horizontally and vertically.
* (2) The sampled array is constructed large enough to (a) cover fpixs
* and (b) have the sampled grid on all boundary pixels in fpixd.
* Having sampled pixels around the boundary simplifies interpolation.
* (3) There must be at least 3 sampled points horizontally and
* vertically.
*/
FPIX *
fpixSampledDisparity(FPIX *fpixs,
l_int32 sampling)
{
l_int32 w, h, wd, hd, i, j, is, js;
l_float32 val;
l_float32 *array;
FPIX *fpixd;
PROCNAME("fpixSampledDisparity");
if (!fpixs)
return (FPIX *)ERROR_PTR("fpixs not defined", procName, NULL);
if (sampling < 1)
return (FPIX *)ERROR_PTR("sampling < 1", procName, NULL);
fpixGetDimensions(fpixs, &w, &h);
wd = 1 + (w + sampling - 2) / sampling;
hd = 1 + (h + sampling - 2) / sampling;
if (wd < 3 || hd < 3)
return (FPIX *)ERROR_PTR("wd < 3 or hd < 3", procName, NULL);
if ((array = (l_float32 *)CALLOC(w, sizeof(l_float32))) == NULL)
return (FPIX *)ERROR_PTR("calloc fail for array", procName, NULL);
fpixd = fpixCreate(wd, hd);
for (i = 0; i < hd; i++) {
is = sampling * i;
if (is >= h) continue;
for (j = 0; j < wd; j++) {
js = sampling * j;
if (js >= w) continue;
fpixGetPixel(fpixs, js, is, &val);
fpixSetPixel(fpixd, j, i, val);
array[j] = val;
}
/* Linear extrapolation to right-hand end point */
fpixSetPixel(fpixd, wd - 1, i, 2 * array[wd - 1] - array[wd - 2]);
}
/* Replicate value to bottom set */
for (j = 0; j < wd; j++) {
fpixGetPixel(fpixd, j, hd - 2, &val);
fpixSetPixel(fpixd, j, hd - 1, val);
}
FREE(array);
return fpixd;
}
