/*!
* pixBilinearPtaGray()
*
* Input: pixs (8 bpp)
* ptad (4 pts of final coordinate space)
* ptas (4 pts of initial coordinate space)
* grayval (0 to bring in BLACK, 255 for WHITE)
* Return: pixd, or null on error
*/
PIX *
pixBilinearPtaGray(PIX *pixs,
PTA *ptad,
PTA *ptas,
l_uint8 grayval)
{
l_float32 *vc;
PIX *pixd;
PROCNAME("pixBilinearPtaGray");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (!ptas)
return (PIX *)ERROR_PTR("ptas not defined", procName, NULL);
if (!ptad)
return (PIX *)ERROR_PTR("ptad not defined", procName, NULL);
if (pixGetDepth(pixs) != 8)
return (PIX *)ERROR_PTR("pixs must be 8 bpp", procName, NULL);
if (ptaGetCount(ptas) != 4)
return (PIX *)ERROR_PTR("ptas count not 4", procName, NULL);
if (ptaGetCount(ptad) != 4)
return (PIX *)ERROR_PTR("ptad count not 4", procName, NULL);
/* Get backwards transform from dest to src, and apply it */
getBilinearXformCoeffs(ptad, ptas, &vc);
pixd = pixBilinearGray(pixs, vc, grayval);
FREE(vc);
return pixd;
}
/*!
* pixBilinearColor()
*
* Input: pixs (32 bpp)
* vc (vector of 8 coefficients for bilinear transformation)
* colorval (e.g., 0 to bring in BLACK, 0xffffff00 for WHITE)
* Return: pixd, or null on error
*/
PIX *
pixBilinearColor(PIX *pixs,
l_float32 *vc,
l_uint32 colorval) {
l_int32 i, j, w, h, d, wpls, wpld;
l_uint32 val;
l_uint32 *datas, *datad, *lined;
l_float32 x, y;
PIX *pix1, *pix2, *pixd;
PROCNAME("pixBilinearColor");
if (!pixs)
return (PIX *) ERROR_PTR("pixs not defined", procName, NULL);
pixGetDimensions(pixs, &w, &h, &d);
if (d != 32)
return (PIX *) ERROR_PTR("pixs must be 32 bpp", procName, NULL);
if (!vc)
return (PIX *) ERROR_PTR("vc not defined", procName, NULL);
datas = pixGetData(pixs);
wpls = pixGetWpl(pixs);
pixd = pixCreateTemplate(pixs);
pixSetAllArbitrary(pixd, colorval);
datad = pixGetData(pixd);
wpld = pixGetWpl(pixd);
/* Iterate over destination pixels */
for (i = 0; i < h; i++) {
lined = datad + i * wpld;
for (j = 0; j < w; j++) {
/* Compute float src pixel location corresponding to (i,j) */
bilinearXformPt(vc, j, i, &x, &y);
linearInterpolatePixelColor(datas, wpls, w, h, x, y, colorval,
&val);
*(lined + j) = val;
}
}
/* If rgba, transform the pixs alpha channel and insert in pixd */
if (pixGetSpp(pixs) == 4) {
pix1 = pixGetRGBComponent(pixs, L_ALPHA_CHANNEL);
pix2 = pixBilinearGray(pix1, vc, 255); /* bring in opaque */
pixSetRGBComponent(pixd, pix2, L_ALPHA_CHANNEL);
pixDestroy(&pix1);
pixDestroy(&pix2);
}
return pixd;
}
/*!
* pixBilinear()
*
* Input: pixs (all depths; colormap ok)
* vc (vector of 8 coefficients for bilinear transformation)
* incolor (L_BRING_IN_WHITE, L_BRING_IN_BLACK)
* Return: pixd, or null on error
*
* Notes:
* (1) Brings in either black or white pixels from the boundary
* (2) Removes any existing colormap, if necessary, before transforming
*/
PIX *
pixBilinear(PIX *pixs,
l_float32 *vc,
l_int32 incolor)
{
l_int32 d;
l_uint32 colorval;
PIX *pixt1, *pixt2, *pixd;
PROCNAME("pixBilinear");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (!vc)
return (PIX *)ERROR_PTR("vc not defined", procName, NULL);
if (pixGetDepth(pixs) == 1)
return pixBilinearSampled(pixs, vc, incolor);
/* Remove cmap if it exists, and unpack to 8 bpp if necessary */
pixt1 = pixRemoveColormap(pixs, REMOVE_CMAP_BASED_ON_SRC);
d = pixGetDepth(pixt1);
if (d < 8)
pixt2 = pixConvertTo8(pixt1, FALSE);
else
pixt2 = pixClone(pixt1);
d = pixGetDepth(pixt2);
/* Compute actual color to bring in from edges */
colorval = 0;
if (incolor == L_BRING_IN_WHITE) {
if (d == 8)
colorval = 255;
else /* d == 32 */
colorval = 0xffffff00;
}
if (d == 8)
pixd = pixBilinearGray(pixt2, vc, colorval);
else /* d == 32 */
pixd = pixBilinearColor(pixt2, vc, colorval);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
return pixd;
}
