l_int32 main(int argc,
char **argv)
{
l_int32 i, n, w, h, val;
l_uint32 val32;
L_AMAP *m;
NUMA *na;
PIX *pix;
PIXCMAP *cmap;
RB_TYPE key, value;
RB_TYPE *pval;
lept_mkdir("lept/map");
pix = pixRead("weasel8.240c.png");
pixGetDimensions(pix, &w, &h, NULL);
fprintf(stderr, "Image area in pixels: %d\n", w * h);
cmap = pixGetColormap(pix);
/* Build the histogram, stored in a map. Then compute
* and display the histogram as the number of pixels vs
* the colormap index */
m = BuildMapHistogram(pix, 1, FALSE);
TestMapIterator1(m, FALSE);
TestMapIterator2(m, FALSE);
DisplayMapHistogram(m, cmap, "/tmp/lept/map/map1");
l_amapDestroy(&m);
/* Ditto, but just with a few pixels */
m = BuildMapHistogram(pix, 14, TRUE);
DisplayMapHistogram(m, cmap, "/tmp/lept/map/map2");
l_amapDestroy(&m);
/* Do in-order tranversals, using the iterators */
m = BuildMapHistogram(pix, 7, FALSE);
TestMapIterator1(m, TRUE);
TestMapIterator2(m, TRUE);
l_amapDestroy(&m);
/* Do in-order tranversals, with iterators and destroying the map */
m = BuildMapHistogram(pix, 7, FALSE);
TestMapIterator3(m, TRUE);
lept_free(m);
m = BuildMapHistogram(pix, 7, FALSE);
TestMapIterator4(m, TRUE);
lept_free(m);
/* Do in-order tranversals, with iterators and reversing the map */
m = BuildMapHistogram(pix, 7, FALSE);
TestMapIterator5(m, TRUE);
l_amapDestroy(&m);
/* Build a histogram the old-fashioned way */
na = pixGetCmapHistogram(pix, 1);
numaWrite("/tmp/lept/map/map2.na", na);
gplotSimple1(na, GPLOT_X11, "/tmp/lept/map/map1", NULL);
numaDestroy(&na);
/* Build a separate map from (rgb) --> colormap index ... */
m = l_amapCreate(L_UINT_TYPE);
n = pixcmapGetCount(cmap);
for (i = 0; i < n; i++) {
pixcmapGetColor32(cmap, i, &val32);
key.utype = val32;
value.itype = i;
l_amapInsert(m, key, value);
}
/* ... and test the map */
for (i = 0; i < n; i++) {
pixcmapGetColor32(cmap, i, &val32);
key.utype = val32;
pval = l_amapFind(m, key);
if (i != pval->itype)
fprintf(stderr, "i = %d != val = %llx\n", i, pval->itype);
}
l_amapDestroy(&m);
pixDestroy(&pix);
return 0;
}
/*!
* \brief pixColorSegmentRemoveColors()
*
* \param[in] pixd 8 bpp, colormapped
* \param[in] pixs 32 bpp rgb, with initial pixel values
* \param[in] finalcolors max number of colors to retain
* \return 0 if OK, 1 on error
*
* <pre>
* Notes:
* (1) This operation is in-place.
* (2) This is phase 4 of color segmentation, and the second part
* of the 2-step noise removal. Only 'finalcolors' different
* colors are retained, with colors with smaller populations
* being replaced by the nearest color of the remaining colors.
* For highest accuracy, for pixels that are being replaced,
* we find the nearest colormap color to the original rgb color.
* </pre>
*/
l_ok
pixColorSegmentRemoveColors(PIX *pixd,
PIX *pixs,
l_int32 finalcolors)
{
l_int32 i, ncolors, index, tempindex;
l_int32 *tab;
l_uint32 tempcolor;
NUMA *na, *nasi;
PIX *pixm;
PIXCMAP *cmap;
PROCNAME("pixColorSegmentRemoveColors");
if (!pixd)
return ERROR_INT("pixd not defined", procName, 1);
if (pixGetDepth(pixd) != 8)
return ERROR_INT("pixd not 8 bpp", procName, 1);
if ((cmap = pixGetColormap(pixd)) == NULL)
return ERROR_INT("cmap not found", procName, 1);
if (!pixs)
return ERROR_INT("pixs not defined", procName, 1);
ncolors = pixcmapGetCount(cmap);
if (finalcolors >= ncolors) /* few enough colors already; nothing to do */
return 0;
/* Generate a mask over all pixels that are not in the
* 'finalcolors' most populated colors. Save the colormap
* index of any one of the retained colors in 'tempindex'.
* The LUT has values 0 for the 'finalcolors' most populated colors,
* which will be retained; and 1 for the rest, which are marked
* by fg pixels in pixm and will be removed. */
na = pixGetCmapHistogram(pixd, 1);
if ((nasi = numaGetSortIndex(na, L_SORT_DECREASING)) == NULL) {
numaDestroy(&na);
return ERROR_INT("nasi not made", procName, 1);
}
numaGetIValue(nasi, finalcolors - 1, &tempindex); /* retain down to this */
pixcmapGetColor32(cmap, tempindex, &tempcolor); /* use this color */
tab = (l_int32 *)LEPT_CALLOC(256, sizeof(l_int32));
for (i = finalcolors; i < ncolors; i++) {
numaGetIValue(nasi, i, &index);
tab[index] = 1;
}
pixm = pixMakeMaskFromLUT(pixd, tab);
LEPT_FREE(tab);
/* Reassign the masked pixels temporarily to the saved index
* (tempindex). This guarantees that no pixels are labeled by
* a colormap index of any colors that will be removed.
* The actual value doesn't matter, as long as it's one
* of the retained colors, because these pixels will later
* be reassigned based on the full set of colors retained
* in the colormap. */
pixSetMasked(pixd, pixm, tempcolor);
/* Now remove unused colors from the colormap. This reassigns
* image pixels as required. */
pixRemoveUnusedColors(pixd);
/* Finally, reassign the pixels under the mask (those that were
* given a 'tempindex' value) to the nearest color in the colormap.
* This is the function used in phase 2 on all image pixels; here
* it is only used on the masked pixels given by pixm. */
pixAssignToNearestColor(pixd, pixs, pixm, LEVEL_IN_OCTCUBE, NULL);
pixDestroy(&pixm);
numaDestroy(&na);
numaDestroy(&nasi);
return 0;
}