/*!
* pixColorSegmentCluster()
*
* Input: pixs (32 bpp; 24-bit color)
* maxdist (max euclidean dist to existing cluster)
* maxcolors (max number of colors allowed in first pass)
* Return: pixd (8 bit with colormap), or null on error
*
* Notes:
* (1) This is phase 1. See description in pixColorSegment().
* (2) Greedy unsupervised classification. If the limit 'maxcolors'
* is exceeded, the computation is repeated with a larger
* allowed cluster size.
* (3) On each successive iteration, 'maxdist' is increased by a
* constant factor. See comments in pixColorSegment() for
* a guideline on parameter selection.
* Note that the diagonal of the 8-bit rgb color cube is about
* 440, so for 'maxdist' = 440, you are guaranteed to get 1 color!
*/
PIX *
pixColorSegmentCluster(PIX *pixs,
l_int32 maxdist,
l_int32 maxcolors)
{
l_int32 w, h, newmaxdist, ret, niters, ncolors, success;
PIX *pixd;
PIXCMAP *cmap;
PROCNAME("pixColorSegmentCluster");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (pixGetDepth(pixs) != 32)
return (PIX *)ERROR_PTR("must be rgb color", procName, NULL);
w = pixGetWidth(pixs);
h = pixGetHeight(pixs);
if ((pixd = pixCreate(w, h, 8)) == NULL)
return (PIX *)ERROR_PTR("pixd not made", procName, NULL);
cmap = pixcmapCreate(8);
pixSetColormap(pixd, cmap);
pixCopyResolution(pixd, pixs);
newmaxdist = maxdist;
niters = 0;
success = TRUE;
while (1) {
ret = pixColorSegmentTryCluster(pixd, pixs, newmaxdist, maxcolors);
niters++;
if (!ret) {
ncolors = pixcmapGetCount(cmap);
L_INFO_INT2("Success with %d colors after %d iters", procName,
ncolors, niters);
break;
}
if (niters == MAX_ALLOWED_ITERATIONS) {
L_WARNING_INT("too many iters; newmaxdist = %d",
procName, newmaxdist);
success = FALSE;
break;
}
newmaxdist = (l_int32)(DIST_EXPAND_FACT * (l_float32)newmaxdist);
}
if (!success) {
pixDestroy(&pixd);
return (PIX *)ERROR_PTR("failure in phase 1", procName, NULL);
}
return pixd;
}
/*!
* pixTilingCreate()
*
* Input: pixs (pix to be tiled; any depth; colormap OK)
* nx (number of tiles across image)
* ny (number of tiles down image)
* w (desired width of each tile)
* h (desired height of each tile)
* overlap (amount of overlap into neighboring tile on each side)
* Return: pixtiling, or null on error
*
* Notes:
* (1) We put a clone of pixs in the PixTiling.
* (2) The input to pixTilingCreate() for horizontal tiling can be
* either the number of tiles across the image or the approximate
* width of the tiles. If the latter, the actual width will be
* determined by making all tiles but the last of equal width, and
* making the last as close to the others as possible. The same
* consideration is applied independently to the vertical tiling.
* To specify tile width, set nx = 0; to specify the number of
* tiles horizontally across the image, set w = 0.
* (3) If pixs is to be tiled in one-dimensional strips, use ny = 1 for
* vertical strips and nx = 1 for horizontal strips.
* (4) The overlap must not be larger than the width or height of
* the leftmost or topmost tile(s).
*/
PIXTILING *
pixTilingCreate(PIX *pixs,
l_int32 nx,
l_int32 ny,
l_int32 w,
l_int32 h,
l_int32 xoverlap,
l_int32 yoverlap)
{
l_int32 width, height;
PIXTILING *pt;
PROCNAME("pixTilingCreate");
if (!pixs)
return (PIXTILING *)ERROR_PTR("pixs not defined", procName, NULL);
if (nx < 1 && w < 1)
return (PIXTILING *)ERROR_PTR("invalid width spec", procName, NULL);
if (ny < 1 && h < 1)
return (PIXTILING *)ERROR_PTR("invalid height spec", procName, NULL);
/* Find the tile width and number of tiles. All tiles except the
* rightmost ones have the same width. The width of the
* rightmost ones are at least the width of the others and
* less than twice that width. Ditto for tile height. */
pixGetDimensions(pixs, &width, &height, NULL);
if (nx == 0)
nx = L_MAX(1, width / w);
w = width / nx; /* possibly reset */
if (ny == 0)
ny = L_MAX(1, height / h);
h = height / ny; /* possibly reset */
if (xoverlap > w || yoverlap > h) {
L_INFO_INT2("tile width = %d, tile height = %d", procName, w, h);
return (PIXTILING *)ERROR_PTR("overlap too large", procName, NULL);
}
if ((pt = (PIXTILING *)CALLOC(1, sizeof(PIXTILING))) == NULL)
return (PIXTILING *)ERROR_PTR("pt not made", procName, NULL);
pt->pix = pixClone(pixs);
pt->xoverlap = xoverlap;
pt->yoverlap = yoverlap;
pt->nx = nx;
pt->ny = ny;
pt->w = w;
pt->h = h;
pt->strip = TRUE;
return pt;
}
/*!
* pixaGenerateFont()
*
* Input: dir (directory holding image of character set)
* size (4, 6, 8, ... , 20, in pts at 300 ppi)
* &bl1 (<return> baseline of row 1)
* &bl2 (<return> baseline of row 2)
* &bl3 (<return> baseline of row 3)
* Return: pixa of font bitmaps for 95 characters, or null on error
*
* These font generation functions use 9 sets, each with bitmaps
* of 94 ascii characters, all in Palatino-Roman font.
* Each input bitmap has 3 rows of characters. The range of
* ascii values in each row is as follows:
* row 0: 32-57 (32 is a space)
* row 1: 58-91 (92, '\', is not represented in this font)
* row 2: 93-126
* We LR flip the '/' char to generate a bitmap for the missing
* '\' character, so that we have representations of all 95
* printable chars.
*
* Computation of the bitmaps and baselines for a single
* font takes from 40 to 200 msec on a 2 GHz processor,
* depending on the size. Use pixaGetFont() to read the
* generated character set directly from files that were
* produced in prog/genfonts.c using this function.
*/
PIXA *
pixaGenerateFont(const char *dir,
l_int32 size,
l_int32 *pbl0,
l_int32 *pbl1,
l_int32 *pbl2)
{
char *pathname;
l_int32 fileno;
l_int32 i, j, nrows, nrowchars, nchars, h, yval;
l_int32 width, height;
l_int32 baseline[3];
l_int32 *tab;
BOX *box, *box1, *box2;
BOXA *boxar, *boxac, *boxacs;
PIX *pixs, *pixt1, *pixt2, *pixt3;
PIX *pixr, *pixrc, *pixc;
PIXA *pixa;
PROCNAME("pixaGenerateFont");
if (!pbl0 || !pbl1 || !pbl2)
return (PIXA *)ERROR_PTR("&bl not all defined", procName, NULL);
*pbl0 = *pbl1 = *pbl2 = 0;
fileno = (size / 2) - 2;
if (fileno < 0 || fileno > NFONTS)
return (PIXA *)ERROR_PTR("font size invalid", procName, NULL);
tab = makePixelSumTab8();
pathname = genPathname(dir, inputfonts[fileno]);
if ((pixs = pixRead(pathname)) == NULL)
return (PIXA *)ERROR_PTR("pixs not all defined", procName, NULL);
FREE(pathname);
pixa = pixaCreate(95);
pixt1 = pixMorphSequence(pixs, "c1.35 + c101.1", 0);
boxar = pixConnComp(pixt1, NULL, 8); /* one box for each row */
pixDestroy(&pixt1);
nrows = boxaGetCount(boxar);
#if DEBUG_FONT_GEN
fprintf(stderr, "For font %s, number of rows is %d\n",
inputfonts[fileno], nrows);
#endif /* DEBUG_FONT_GEN */
if (nrows != 3) {
L_INFO_INT2("nrows = %d; skipping font %d", procName, nrows, fileno);
return (PIXA *)ERROR_PTR("3 rows not generated", procName, NULL);
}
for (i = 0; i < nrows; i++) {
box = boxaGetBox(boxar, i, L_CLONE);
pixr = pixClipRectangle(pixs, box, NULL); /* row of chars */
pixGetTextBaseline(pixr, tab, &yval);
baseline[i] = yval;
#if DEBUG_BASELINE
{ PIX *pixbl;
fprintf(stderr, "row %d, yval = %d, h = %d\n",
i, yval, pixGetHeight(pixr));
pixbl = pixCopy(NULL, pixr);
pixRenderLine(pixbl, 0, yval, pixGetWidth(pixbl), yval, 1,
L_FLIP_PIXELS);
if (i == 0 )
pixWrite("junktl0", pixbl, IFF_PNG);
else if (i == 1)
pixWrite("junktl1", pixbl, IFF_PNG);
else
pixWrite("junktl2", pixbl, IFF_PNG);
pixDestroy(&pixbl);
}
#endif /* DEBUG_BASELINE */
boxDestroy(&box);
pixrc = pixCloseSafeBrick(NULL, pixr, 1, 35);
boxac = pixConnComp(pixrc, NULL, 8);
boxacs = boxaSort(boxac, L_SORT_BY_X, L_SORT_INCREASING, NULL);
if (i == 0) { /* consolidate the two components of '"' */
box1 = boxaGetBox(boxacs, 1, L_CLONE);
box2 = boxaGetBox(boxacs, 2, L_CLONE);
box1->w = box2->x + box2->w - box1->x; /* increase width */
boxDestroy(&box1);
boxDestroy(&box2);
boxaRemoveBox(boxacs, 2);
}
h = pixGetHeight(pixr);
nrowchars = boxaGetCount(boxacs);
for (j = 0; j < nrowchars; j++) {
box = boxaGetBox(boxacs, j, L_COPY);
if (box->w <= 2 && box->h == 1) { /* skip 1x1, 2x1 components */
boxDestroy(&box);
continue;
}
box->y = 0;
box->h = h - 1;
pixc = pixClipRectangle(pixr, box, NULL);
boxDestroy(&box);
if (i == 0 && j == 0) /* add a pix for the space; change later */
pixaAddPix(pixa, pixc, L_COPY);
if (i == 2 && j == 0) /* add a pix for the '\'; change later */
pixaAddPix(pixa, pixc, L_COPY);
pixaAddPix(pixa, pixc, L_INSERT);
}
pixDestroy(&pixr);
pixDestroy(&pixrc);
boxaDestroy(&boxac);
boxaDestroy(&boxacs);
}
nchars = pixaGetCount(pixa);
if (nchars != 95)
return (PIXA *)ERROR_PTR("95 chars not generated", procName, NULL);
*pbl0 = baseline[0];
*pbl1 = baseline[1];
*pbl2 = baseline[2];
/* Fix the space character up; it should have no ON pixels,
* and be about twice as wide as the '!' character. */
pixt2 = pixaGetPix(pixa, 0, L_CLONE);
width = 2 * pixGetWidth(pixt2);
height = pixGetHeight(pixt2);
pixDestroy(&pixt2);
pixt2 = pixCreate(width, height, 1);
pixaReplacePix(pixa, 0, pixt2, NULL);
/* Fix up the '\' character; use a LR flip of the '/' char */
pixt2 = pixaGetPix(pixa, 15, L_CLONE);
pixt3 = pixFlipLR(NULL, pixt2);
pixDestroy(&pixt2);
pixaReplacePix(pixa, 60, pixt3, NULL);
#if DEBUG_CHARS
{ PIX *pixd;
pixd = pixaDisplayTiled(pixa, 1500, 0, 10);
pixDisplay(pixd, 100 * i, 200);
pixDestroy(&pixd);
}
#endif /* DEBUG_CHARS */
pixDestroy(&pixs);
boxaDestroy(&boxar);
FREE(tab);
return pixa;
}
