/*!
* 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;
}
/*!
* \brief pixRotate3Shear()
*
* \param[in] pixs
* \param[in] xcen, ycen center of rotation
* \param[in] angle radians
* \param[in] incolor L_BRING_IN_WHITE, L_BRING_IN_BLACK;
* \return pixd, or NULL on error.
*
* <pre>
* Notes:
* (1) This rotates the image about the given point, using the 3-shear
* method. It should only be used for angles smaller than
* LIMIT_SHEAR_ANGLE. For larger angles, a warning is issued.
* (2) A positive angle gives a clockwise rotation.
* (3) 3-shear rotation by a specified angle is equivalent
* to the sequential transformations
* y' = y + tan(angle/2) * (x - xcen) for first y-shear
* x' = x + sin(angle) * (y - ycen) for x-shear
* y' = y + tan(angle/2) * (x - xcen) for second y-shear
* (4) Computation of tan(angle) is performed in the shear operations.
* (5) This brings in 'incolor' pixels from outside the image.
* (6) If the image has an alpha layer, it is rotated separately by
* two shears.
* (7) The algorithm was published by Alan Paeth: "A Fast Algorithm
* for General Raster Rotation," Graphics Interface '86,
* pp. 77-81, May 1986. A description of the method, along with
* an implementation, can be found in Graphics Gems, p. 179,
* edited by Andrew Glassner, published by Academic Press, 1990.
* </pre>
*/
PIX *
pixRotate3Shear(PIX *pixs,
l_int32 xcen,
l_int32 ycen,
l_float32 angle,
l_int32 incolor)
{
l_float32 hangle;
PIX *pix1, *pix2, *pixd;
PROCNAME("pixRotate3Shear");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (incolor != L_BRING_IN_WHITE && incolor != L_BRING_IN_BLACK)
return (PIX *)(PIX *)ERROR_PTR("invalid incolor value", procName, NULL);
if (L_ABS(angle) < MIN_ANGLE_TO_ROTATE)
return pixClone(pixs);
if (L_ABS(angle) > LIMIT_SHEAR_ANGLE) {
L_WARNING("%6.2f radians; large angle for 3-shear rotation\n",
procName, L_ABS(angle));
}
hangle = atan(sin(angle));
if ((pixd = pixVShear(NULL, pixs, xcen, angle / 2., incolor)) == NULL)
return (PIX *)ERROR_PTR("pixd not made", procName, NULL);
if ((pix1 = pixHShear(NULL, pixd, ycen, hangle, incolor)) == NULL) {
pixDestroy(&pixd);
return (PIX *)ERROR_PTR("pix1 not made", procName, NULL);
}
pixVShear(pixd, pix1, xcen, angle / 2., incolor);
pixDestroy(&pix1);
if (pixGetDepth(pixs) == 32 && pixGetSpp(pixs) == 4) {
pix1 = pixGetRGBComponent(pixs, L_ALPHA_CHANNEL);
/* L_BRING_IN_WHITE brings in opaque for the alpha component */
pix2 = pixRotate3Shear(pix1, xcen, ycen, angle, L_BRING_IN_WHITE);
pixSetRGBComponent(pixd, pix2, L_ALPHA_CHANNEL);
pixDestroy(&pix1);
pixDestroy(&pix2);
}
return pixd;
}
/*!
* pixRotateAMColorCorner()
*
* Input: pixs
* angle (radians; clockwise is positive)
* colorval (e.g., 0 to bring in BLACK, 0xffffff00 for WHITE)
* Return: pixd, or null on error
*
* Notes:
* (1) Rotates the image about the UL corner.
* (2) A positive angle gives a clockwise rotation.
* (3) Specify the color to be brought in from outside the image.
*/
PIX *
pixRotateAMColorCorner(PIX *pixs,
l_float32 angle,
l_uint32 fillval)
{
l_int32 w, h, wpls, wpld;
l_uint32 *datas, *datad;
PIX *pix1, *pix2, *pixd;
PROCNAME("pixRotateAMColorCorner");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (pixGetDepth(pixs) != 32)
return (PIX *)ERROR_PTR("pixs must be 32 bpp", procName, NULL);
if (L_ABS(angle) < MIN_ANGLE_TO_ROTATE)
return pixClone(pixs);
pixGetDimensions(pixs, &w, &h, NULL);
datas = pixGetData(pixs);
wpls = pixGetWpl(pixs);
pixd = pixCreateTemplate(pixs);
datad = pixGetData(pixd);
wpld = pixGetWpl(pixd);
rotateAMColorCornerLow(datad, w, h, wpld, datas, wpls, angle, fillval);
if (pixGetSpp(pixs) == 4) {
pix1 = pixGetRGBComponent(pixs, L_ALPHA_CHANNEL);
pix2 = pixRotateAMGrayCorner(pix1, angle, 255); /* bring in opaque */
pixSetRGBComponent(pixd, pix2, L_ALPHA_CHANNEL);
pixDestroy(&pix1);
pixDestroy(&pix2);
}
return pixd;
}
int main(int argc,
char **argv)
{
l_uint8 *data;
l_int32 w, h, n1, n2, n, i, minval, maxval;
l_int32 ncolors, rval, gval, bval, equal;
l_int32 *rmap, *gmap, *bmap;
l_uint32 color;
l_float32 gamma;
BOX *box;
FILE *fp;
PIX *pix1, *pix2, *pix3, *pix4, *pix5, *pix6;
PIX *pixs, *pixb, *pixg, *pixc, *pixd;
PIX *pixg2, *pixcs1, *pixcs2, *pixd1, *pixd2;
PIXA *pixa, *pixa2, *pixa3;
PIXCMAP *cmap, *cmap2;
RGBA_QUAD *cta;
L_REGPARAMS *rp;
if (regTestSetup(argc, argv, &rp))
return 1;
/* ------------------------ (1) ----------------------------*/
/* Blend with a white background */
pix1 = pixRead("books_logo.png");
pixDisplayWithTitle(pix1, 100, 0, NULL, rp->display);
pix2 = pixAlphaBlendUniform(pix1, 0xffffff00);
pixDisplayWithTitle(pix2, 100, 150, NULL, rp->display);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 0 */
regTestWritePixAndCheck(rp, pix2, IFF_PNG); /* 1 */
/* Generate an alpha layer based on the white background */
pix3 = pixSetAlphaOverWhite(pix2);
pixSetSpp(pix3, 3);
pixWrite("/tmp/alphaops.2.png", pix3, IFF_PNG); /* without alpha */
regTestCheckFile(rp, "/tmp/alphaops.2.png"); /* 2 */
pixSetSpp(pix3, 4);
regTestWritePixAndCheck(rp, pix3, IFF_PNG); /* 3, with alpha */
pixDisplayWithTitle(pix3, 100, 300, NULL, rp->display);
/* Render on a light yellow background */
pix4 = pixAlphaBlendUniform(pix3, 0xffffe000);
regTestWritePixAndCheck(rp, pix4, IFF_PNG); /* 4 */
pixDisplayWithTitle(pix4, 100, 450, NULL, rp->display);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
pixDestroy(&pix4);
/* ------------------------ (2) ----------------------------*/
lept_rmdir("alpha");
lept_mkdir("alpha");
/* Make the transparency (alpha) layer.
* pixs is the mask. We turn it into a transparency (alpha)
* layer by converting to 8 bpp. A small convolution fuzzes
* the mask edges so that you don't see the pixels. */
pixs = pixRead("feyn-fract.tif");
pixGetDimensions(pixs, &w, &h, NULL);
pixg = pixConvert1To8(NULL, pixs, 0, 255);
pixg2 = pixBlockconvGray(pixg, NULL, 1, 1);
regTestWritePixAndCheck(rp, pixg2, IFF_JFIF_JPEG); /* 5 */
pixDisplayWithTitle(pixg2, 0, 0, "alpha", rp->display);
/* Make the viewable image.
* pixc is the image that we see where the alpha layer is
* opaque -- i.e., greater than 0. Scale it to the same
* size as the mask. To visualize what this will look like
* when displayed over a black background, create the black
* background image, pixb, and do the blending with pixcs1
* explicitly using the alpha layer pixg2. */
pixc = pixRead("tetons.jpg");
pixcs1 = pixScaleToSize(pixc, w, h);
regTestWritePixAndCheck(rp, pixcs1, IFF_JFIF_JPEG); /* 6 */
pixDisplayWithTitle(pixcs1, 300, 0, "viewable", rp->display);
pixb = pixCreateTemplate(pixcs1); /* black */
pixd1 = pixBlendWithGrayMask(pixb, pixcs1, pixg2, 0, 0);
regTestWritePixAndCheck(rp, pixd1, IFF_JFIF_JPEG); /* 7 */
pixDisplayWithTitle(pixd1, 600, 0, "alpha-blended 1", rp->display);
/* Embed the alpha layer pixg2 into the color image pixc.
* Write it out as is. Then clean pixcs1 (to 0) under the fully
* transparent part of the alpha layer, and write that result
* out as well. */
pixSetRGBComponent(pixcs1, pixg2, L_ALPHA_CHANNEL);
pixWrite("/tmp/alpha/pixcs1.png", pixcs1, IFF_PNG);
pixcs2 = pixSetUnderTransparency(pixcs1, 0, 0);
pixWrite("/tmp/alpha/pixcs2.png", pixcs2, IFF_PNG);
/* What will this look like over a black background?
* Do the blending explicitly and display. It should
* look identical to the blended result pixd1 before cleaning. */
pixd2 = pixBlendWithGrayMask(pixb, pixcs2, pixg2, 0, 0);
regTestWritePixAndCheck(rp, pixd2, IFF_JFIF_JPEG); /* 8 */
pixDisplayWithTitle(pixd2, 0, 400, "alpha blended 2", rp->display);
/* Read the two images back, ignoring the transparency layer.
* The uncleaned image will come back identical to pixcs1.
* However, the cleaned image will be black wherever
* the alpha layer was fully transparent. It will
* look the same when viewed through the alpha layer,
* but have much better compression. */
pix1 = pixRead("/tmp/alpha/pixcs1.png"); /* just pixcs1 */
pix2 = pixRead("/tmp/alpha/pixcs2.png"); /* cleaned under transparent */
n1 = nbytesInFile("/tmp/alpha/pixcs1.png");
n2 = nbytesInFile("/tmp/alpha/pixcs2.png");
fprintf(stderr, " Original: %d bytes\n Cleaned: %d bytes\n", n1, n2);
regTestWritePixAndCheck(rp, pix1, IFF_JFIF_JPEG); /* 9 */
regTestWritePixAndCheck(rp, pix2, IFF_JFIF_JPEG); /* 10 */
pixDisplayWithTitle(pix1, 300, 400, "without alpha", rp->display);
pixDisplayWithTitle(pix2, 600, 400, "cleaned under transparent",
rp->display);
pixa = pixaCreate(0);
pixSaveTiled(pixg2, pixa, 1.0, 1, 20, 32);
pixSaveTiled(pixcs1, pixa, 1.0, 1, 20, 0);
pixSaveTiled(pix1, pixa, 1.0, 0, 20, 0);
pixSaveTiled(pixd1, pixa, 1.0, 1, 20, 0);
pixSaveTiled(pixd2, pixa, 1.0, 0, 20, 0);
pixSaveTiled(pix2, pixa, 1.0, 1, 20, 0);
pixd = pixaDisplay(pixa, 0, 0);
regTestWritePixAndCheck(rp, pixd, IFF_JFIF_JPEG); /* 11 */
pixDisplayWithTitle(pixd, 200, 200, "composite", rp->display);
pixWrite("/tmp/alpha/alpha.png", pixd, IFF_JFIF_JPEG);
pixDestroy(&pixd);
pixaDestroy(&pixa);
pixDestroy(&pixs);
pixDestroy(&pixb);
pixDestroy(&pixg);
pixDestroy(&pixg2);
pixDestroy(&pixc);
pixDestroy(&pixcs1);
pixDestroy(&pixcs2);
pixDestroy(&pixd);
pixDestroy(&pixd1);
pixDestroy(&pixd2);
pixDestroy(&pix1);
pixDestroy(&pix2);
/* ------------------------ (3) ----------------------------*/
color = 0xffffa000;
gamma = 1.0;
minval = 0;
maxval = 200;
box = boxCreate(0, 85, 600, 100);
pixa = pixaCreate(6);
pix1 = pixRead("blend-green1.jpg");
pixaAddPix(pixa, pix1, L_INSERT);
pix1 = pixRead("blend-green2.png");
pixaAddPix(pixa, pix1, L_INSERT);
pix1 = pixRead("blend-green3.png");
pixaAddPix(pixa, pix1, L_INSERT);
pix1 = pixRead("blend-orange.jpg");
pixaAddPix(pixa, pix1, L_INSERT);
pix1 = pixRead("blend-yellow.jpg");
pixaAddPix(pixa, pix1, L_INSERT);
pix1 = pixRead("blend-red.png");
pixaAddPix(pixa, pix1, L_INSERT);
n = pixaGetCount(pixa);
pixa2 = pixaCreate(n);
pixa3 = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixa, i, L_CLONE);
pix2 = DoBlendTest(pix1, box, color, gamma, minval, maxval, 1);
regTestWritePixAndCheck(rp, pix2, IFF_JFIF_JPEG); /* 12, 14, ... 22 */
pixDisplayWithTitle(pix2, 150 * i, 0, NULL, rp->display);
pixaAddPix(pixa2, pix2, L_INSERT);
pix2 = DoBlendTest(pix1, box, color, gamma, minval, maxval, 2);
regTestWritePixAndCheck(rp, pix2, IFF_JFIF_JPEG); /* 13, 15, ... 23 */
pixDisplayWithTitle(pix2, 150 * i, 200, NULL, rp->display);
pixaAddPix(pixa3, pix2, L_INSERT);
pixDestroy(&pix1);
}
if (rp->display) {
pixaConvertToPdf(pixa2, 0, 0.75, L_FLATE_ENCODE, 0, "blend 1 test",
"/tmp/alpha/blending1.pdf");
pixaConvertToPdf(pixa3, 0, 0.75, L_FLATE_ENCODE, 0, "blend 2 test",
"/tmp/alpha/blending2.pdf");
}
pixaDestroy(&pixa);
pixaDestroy(&pixa2);
pixaDestroy(&pixa3);
boxDestroy(&box);
/* ------------------------ (4) ----------------------------*/
/* Use one image as the alpha component for a second image */
pix1 = pixRead("test24.jpg");
pix2 = pixRead("marge.jpg");
pix3 = pixScale(pix2, 1.9, 2.2);
pix4 = pixConvertTo8(pix3, 0);
pixSetRGBComponent(pix1, pix4, L_ALPHA_CHANNEL);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 24 */
pixDisplayWithTitle(pix1, 600, 0, NULL, rp->display);
/* Set the alpha value in a colormap to bval */
pix5 = pixOctreeColorQuant(pix1, 128, 0);
cmap = pixGetColormap(pix5);
pixcmapToArrays(cmap, &rmap, &gmap, &bmap, NULL);
n = pixcmapGetCount(cmap);
for (i = 0; i < n; i++) {
pixcmapGetColor(cmap, i, &rval, &gval, &bval);
cta = (RGBA_QUAD *)cmap->array;
cta[i].alpha = bval;
}
/* Test binary serialization/deserialization of colormap with alpha */
pixcmapSerializeToMemory(cmap, 4, &ncolors, &data);
cmap2 = pixcmapDeserializeFromMemory(data, 4, ncolors);
CmapEqual(cmap, cmap2, &equal);
regTestCompareValues(rp, TRUE, equal, 0.0); /* 25 */
pixcmapDestroy(&cmap2);
lept_free(data);
/* Test ascii serialization/deserialization of colormap with alpha */
fp = fopenWriteStream("/tmp/alpha/cmap.4", "w");
pixcmapWriteStream(fp, cmap);
fclose(fp);
fp = fopenReadStream("/tmp/alpha/cmap.4");
cmap2 = pixcmapReadStream(fp);
fclose(fp);
CmapEqual(cmap, cmap2, &equal);
regTestCompareValues(rp, TRUE, equal, 0.0); /* 26 */
pixcmapDestroy(&cmap2);
/* Test r/w for cmapped pix with non-opaque alpha */
pixDisplayWithTitle(pix5, 900, 0, NULL, rp->display);
regTestWritePixAndCheck(rp, pix5, IFF_PNG); /* 27 */
pixWrite("/tmp/alpha/fourcomp.png", pix5, IFF_PNG);
pix6 = pixRead("/tmp/alpha/fourcomp.png");
regTestComparePix(rp, pix5, pix6); /* 28 */
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
pixDestroy(&pix4);
pixDestroy(&pix5);
pixDestroy(&pix6);
lept_free(rmap);
lept_free(gmap);
lept_free(bmap);
return regTestCleanup(rp);
}
int main(int argc,
char **argv)
{
l_int32 w, h, x, y, i, n;
l_float32 *vc;
PIX *pix1, *pix2, *pix3, *pix4, *pix5;
PIXA *pixas, *pixa;
L_REGPARAMS *rp;
if (regTestSetup(argc, argv, &rp))
return 1;
pixas = pixaCreate(11);
for (i = 0; i < 10; i++) { /* this preserves any alpha */
pix1 = pixRead(fnames[i]);
pix2 = pixScaleBySamplingToSize(pix1, 250, 150);
pixaAddPix(pixas, pix2, L_INSERT);
pixDestroy(&pix1);
}
/* Add a transparent grid over the rgb image */
pix1 = pixaGetPix(pixas, 8, L_COPY);
pixGetDimensions(pix1, &w, &h, NULL);
pix2 = pixCreate(w, h, 1);
for (i = 0; i < 5; i++) {
y = h * (i + 1) / 6;
pixRenderLine(pix2, 0, y, w, y, 3, L_SET_PIXELS);
}
for (i = 0; i < 7; i++) {
x = w * (i + 1) / 8;
pixRenderLine(pix2, x, 0, x, h, 3, L_SET_PIXELS);
}
pix3 = pixConvertTo8(pix2, 0); /* 1 --> 0 ==> transparent */
pixSetRGBComponent(pix1, pix3, L_ALPHA_CHANNEL);
pixaAddPix(pixas, pix1, L_INSERT);
n = pixaGetCount(pixas);
pixDestroy(&pix2);
pixDestroy(&pix3);
#if DO_ALL
/* Display with and without removing alpha with white bg */
pix1 = pixaDisplayTiledInRows(pixas, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 0 */
pixDisplayWithTitle(pix1, 0, 0, NULL, rp->display);
pixDestroy(&pix1);
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixRemoveAlpha(pix1);
pixaAddPix(pixa, pix2, L_INSERT);
pixDestroy(&pix1);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 1 */
pixDisplayWithTitle(pix1, 200, 0, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* Setting to gray */
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pixSetAllGray(pix1, 170);
pix2 = pixRemoveAlpha(pix1);
pixaAddPix(pixa, pix2, L_INSERT);
pixDestroy(&pix1);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 2 */
pixDisplayWithTitle(pix1, 400, 0, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* General scaling */
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixScaleToSize(pix1, 350, 650);
pix3 = pixScaleToSize(pix2, 200, 200);
pix4 = pixRemoveAlpha(pix3);
pixaAddPix(pixa, pix4, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 3 */
pixDisplayWithTitle(pix1, 600, 0, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* Scaling by sampling */
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixScaleBySamplingToSize(pix1, 350, 650);
pix3 = pixScaleBySamplingToSize(pix2, 200, 200);
pix4 = pixRemoveAlpha(pix3);
pixaAddPix(pixa, pix4, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 4 */
pixDisplayWithTitle(pix1, 800, 0, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* Rotation by area mapping; no embedding */
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixRotate(pix1, 0.25, L_ROTATE_AREA_MAP,
L_BRING_IN_WHITE, 0, 0);
pix3 = pixRotate(pix2, -0.35, L_ROTATE_AREA_MAP,
L_BRING_IN_WHITE, 0, 0);
pix4 = pixRemoveAlpha(pix3);
pixaAddPix(pixa, pix4, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 5 */
pixDisplayWithTitle(pix1, 1000, 0, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* Rotation by area mapping; with embedding */
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixRotate(pix1, 0.25, L_ROTATE_AREA_MAP,
L_BRING_IN_WHITE, 250, 150);
pix3 = pixRotate(pix2, -0.35, L_ROTATE_AREA_MAP,
L_BRING_IN_WHITE, 250, 150);
pix4 = pixRemoveBorderToSize(pix3, 250, 150);
pix5 = pixRemoveAlpha(pix4);
pixaAddPix(pixa, pix5, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
pixDestroy(&pix4);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 6 */
pixDisplayWithTitle(pix1, 0, 400, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* Rotation by 3-shear; no embedding */
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixRotate(pix1, 0.25, L_ROTATE_SHEAR,
L_BRING_IN_WHITE, 0, 0);
pix3 = pixRotate(pix2, -0.35, L_ROTATE_SHEAR,
L_BRING_IN_WHITE, 0, 0);
pix4 = pixRemoveAlpha(pix3);
pixaAddPix(pixa, pix4, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 7 */
pixDisplayWithTitle(pix1, 200, 400, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* Rotation by 3-shear; with embedding */
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixRotate(pix1, 0.25, L_ROTATE_SHEAR,
L_BRING_IN_WHITE, 250, 150);
pix3 = pixRotate(pix2, -0.35, L_ROTATE_SHEAR,
L_BRING_IN_WHITE, 250, 150);
pix4 = pixRemoveBorderToSize(pix3, 250, 150);
pix5 = pixRemoveAlpha(pix4);
pixaAddPix(pixa, pix5, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
pixDestroy(&pix4);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 8 */
pixDisplayWithTitle(pix1, 400, 400, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* Rotation by 2-shear about the center */
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pixGetDimensions(pix1, &w, &h, NULL);
pix2 = pixRotate2Shear(pix1, w / 2, h / 2, 0.25, L_BRING_IN_WHITE);
pix3 = pixRotate2Shear(pix2, w / 2, h / 2, -0.35, L_BRING_IN_WHITE);
pix4 = pixRemoveAlpha(pix3);
pixaAddPix(pixa, pix4, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 9 */
pixDisplayWithTitle(pix1, 600, 400, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* Rotation by sampling; no embedding */
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixRotate(pix1, 0.25, L_ROTATE_SAMPLING,
L_BRING_IN_WHITE, 0, 0);
pix3 = pixRotate(pix2, -0.35, L_ROTATE_SAMPLING,
L_BRING_IN_WHITE, 0, 0);
pix4 = pixRemoveAlpha(pix3);
pixaAddPix(pixa, pix4, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 10 */
pixDisplayWithTitle(pix1, 800, 400, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* Rotation by sampling; with embedding */
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixRotate(pix1, 0.25, L_ROTATE_SAMPLING,
L_BRING_IN_WHITE, 250, 150);
pix3 = pixRotate(pix2, -0.35, L_ROTATE_SAMPLING,
L_BRING_IN_WHITE, 250, 150);
pix4 = pixRemoveBorderToSize(pix3, 250, 150);
pix5 = pixRemoveAlpha(pix4);
pixaAddPix(pixa, pix5, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
pixDestroy(&pix4);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 11 */
pixDisplayWithTitle(pix1, 1000, 400, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* Rotation by area mapping at corner */
pixa = pixaCreate(n);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixRotateAMCorner(pix1, 0.25, L_BRING_IN_WHITE);
pix3 = pixRotateAMCorner(pix2, -0.35, L_BRING_IN_WHITE);
pix4 = pixRemoveAlpha(pix3);
pixaAddPix(pixa, pix4, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
pixDestroy(&pix3);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 12 */
pixDisplayWithTitle(pix1, 0, 800, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
#endif
#if DO_ALL
/* Affine transform by interpolation */
pixa = pixaCreate(n);
vc = Generate3PtTransformVector();
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixAffine(pix1, vc, L_BRING_IN_WHITE);
/* pix2 = pixAffineSampled(pix1, vc, L_BRING_IN_WHITE); */
pix3 = pixRemoveAlpha(pix2);
pixaAddPix(pixa, pix3, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 13 */
pixDisplayWithTitle(pix1, 200, 800, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
lept_free(vc);
#endif
#if DO_ALL
/* Projective transform by sampling */
pixa = pixaCreate(n);
vc = Generate4PtTransformVector(PROJECTIVE);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixProjectiveSampled(pix1, vc, L_BRING_IN_WHITE);
pix3 = pixRemoveAlpha(pix2);
pixaAddPix(pixa, pix3, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 14 */
pixDisplayWithTitle(pix1, 400, 800, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
lept_free(vc);
#endif
#if DO_ALL
/* Projective transform by interpolation */
pixa = pixaCreate(n);
vc = Generate4PtTransformVector(PROJECTIVE);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixProjective(pix1, vc, L_BRING_IN_WHITE);
pix3 = pixRemoveAlpha(pix2);
pixaAddPix(pixa, pix3, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 15 */
pixDisplayWithTitle(pix1, 600, 800, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
lept_free(vc);
#endif
#if DO_ALL
/* Bilinear transform by interpolation */
pixa = pixaCreate(n);
vc = Generate4PtTransformVector(BILINEAR);
for (i = 0; i < n; i++) {
pix1 = pixaGetPix(pixas, i, L_COPY);
pix2 = pixBilinear(pix1, vc, L_BRING_IN_WHITE);
pix3 = pixRemoveAlpha(pix2);
pixaAddPix(pixa, pix3, L_INSERT);
pixDestroy(&pix1);
pixDestroy(&pix2);
}
pix1 = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 25, 2);
regTestWritePixAndCheck(rp, pix1, IFF_PNG); /* 16 */
pixDisplayWithTitle(pix1, 800, 800, NULL, rp->display);
pixDestroy(&pix1);
pixaDestroy(&pixa);
lept_free(vc);
#endif
pixaDestroy(&pixas);
return regTestCleanup(rp);
}
main(int argc,
char **argv)
{
l_int32 i, j, w1, h1, w2, h2, w, h, same;
BOX *box1, *box2;
PIX *pixs, *pixs1, *pixs2, *pix1, *pix2;
PIX *pixg, *pixg1, *pixg2, *pixc2, *pixbl, *pixd;
PIXA *pixa;
static char mainName[] = "blend2_reg";
/* --- Set up the 8 bpp blending image --- */
pixg = pixCreate(660, 500, 8);
for (i = 0; i < 500; i++)
for (j = 0; j < 660; j++)
pixSetPixel(pixg, j, i, (l_int32)(0.775 * j) % 256);
/* --- Set up the initial color images to be blended together --- */
pixs1 = pixRead("wyom.jpg");
pixs2 = pixRead("fish24.jpg");
pixGetDimensions(pixs1, &w1, &h1, NULL);
pixGetDimensions(pixs2, &w2, &h2, NULL);
h = L_MIN(h1, h2);
w = L_MIN(w1, w2);
box1 = boxCreate(0, 0, w1, h1);
box2 = boxCreate(0, 300, 660, 500);
pix1 = pixClipRectangle(pixs1, box1, NULL);
pix2 = pixClipRectangle(pixs2, box2, NULL);
pixDestroy(&pixs1);
pixDestroy(&pixs2);
boxDestroy(&box1);
boxDestroy(&box2);
/* --- Blend 2 rgb images --- */
pixa = pixaCreate(0);
pixSaveTiled(pixg, pixa, 1, 1, 40, 32);
pixd = pixBlendWithGrayMask(pix1, pix2, pixg, 50, 50);
pixSaveTiled(pix1, pixa, 1, 1, 40, 32);
pixSaveTiled(pix2, pixa, 1, 0, 40, 32);
pixSaveTiled(pixd, pixa, 1, 0, 40, 32);
pixDestroy(&pixd);
/* --- Blend 2 grayscale images --- */
pixg1 = pixConvertRGBToLuminance(pix1);
pixg2 = pixConvertRGBToLuminance(pix2);
pixd = pixBlendWithGrayMask(pixg1, pixg2, pixg, 50, 50);
pixSaveTiled(pixg1, pixa, 1, 1, 40, 32);
pixSaveTiled(pixg2, pixa, 1, 0, 40, 32);
pixSaveTiled(pixd, pixa, 1, 0, 40, 32);
pixDestroy(&pixg1);
pixDestroy(&pixg2);
pixDestroy(&pixd);
/* --- Blend a colormap image and an rgb image --- */
pixc2 = pixFixedOctcubeQuantGenRGB(pix2, 2);
pixd = pixBlendWithGrayMask(pix1, pixc2, pixg, 50, 50);
pixSaveTiled(pix1, pixa, 1, 1, 40, 32);
pixSaveTiled(pixc2, pixa, 1, 0, 40, 32);
pixSaveTiled(pixd, pixa, 1, 0, 40, 32);
pixDestroy(&pixc2);
pixDestroy(&pixd);
/* --- Blend a colormap image and a grayscale image --- */
pixg1 = pixConvertRGBToLuminance(pix1);
pixc2 = pixFixedOctcubeQuantGenRGB(pix2, 2);
pixd = pixBlendWithGrayMask(pixg1, pixc2, pixg, 50, 50);
pixSaveTiled(pixg1, pixa, 1, 1, 40, 32);
pixSaveTiled(pixc2, pixa, 1, 0, 40, 32);
pixSaveTiled(pixd, pixa, 1, 0, 40, 32);
pixDestroy(&pixd);
pixd = pixBlendWithGrayMask(pixg1, pixc2, pixg, -100, -100);
pixSaveTiled(pixg1, pixa, 1, 1, 40, 32);
pixSaveTiled(pixc2, pixa, 1, 0, 40, 32);
pixSaveTiled(pixd, pixa, 1, 0, 40, 32);
pixDestroy(&pixd);
pixDestroy(&pixg1);
pixDestroy(&pixc2);
/* --- Test png read/write with alpha channel --- */
/* First make pixs1, using pixg as the alpha channel */
pixs = pixRead("fish24.jpg");
box1 = boxCreate(0, 300, 660, 500);
pixs1 = pixClipRectangle(pixs, box1, NULL);
pixSaveTiled(pixs1, pixa, 1, 1, 40, 32);
pixSetRGBComponent(pixs1, pixg, L_ALPHA_CHANNEL);
/* To see the alpha channel, blend with a black image */
pixbl = pixCreate(660, 500, 32);
pixd = pixBlendWithGrayMask(pixbl, pixs1, NULL, 0, 0);
pixSaveTiled(pixd, pixa, 1, 0, 40, 32);
pixDestroy(&pixd);
/* Write out the RGBA image and read it back */
l_pngSetWriteAlpha(1);
pixWrite("/tmp/junkpixs1.png", pixs1, IFF_PNG);
l_pngSetStripAlpha(0);
pixs2 = pixRead("/tmp/junkpixs1.png");
/* Make sure that the alpha channel image hasn't changed */
pixg2 = pixGetRGBComponent(pixs2, L_ALPHA_CHANNEL);
pixEqual(pixg, pixg2, &same);
if (same)
fprintf(stderr, "PNG with alpha read/write OK\n");
else
fprintf(stderr, "PNG with alpha read/write failed\n");
/* Blend again with a black image */
pixd = pixBlendWithGrayMask(pixbl, pixs2, NULL, 0, 0);
pixSaveTiled(pixd, pixa, 1, 0, 40, 32);
pixDestroy(&pixd);
/* Blend with a white image */
pixSetAll(pixbl);
pixd = pixBlendWithGrayMask(pixbl, pixs2, NULL, 0, 0);
pixSaveTiled(pixd, pixa, 1, 0, 40, 32);
pixDestroy(&pixd);
l_pngSetWriteAlpha(0); /* reset to default */
l_pngSetStripAlpha(1); /* reset to default */
pixDestroy(&pixbl);
pixDestroy(&pixs);
pixDestroy(&pixs1);
pixDestroy(&pixs2);
pixDestroy(&pixg2);
boxDestroy(&box1);
/* --- Display results --- */
pixd = pixaDisplay(pixa, 0, 0);
pixDisplay(pixd, 100, 100);
pixWrite("/tmp/junkblend2.jpg", pixd, IFF_JFIF_JPEG);
pixDestroy(&pixd);
pixaDestroy(&pixa);
pixDestroy(&pixg);
pixDestroy(&pix1);
pixDestroy(&pix2);
return 0;
}
/*!
* pixProjectivePtaWithAlpha()
*
* Input: pixs (32 bpp rgb)
* ptad (4 pts of final coordinate space)
* ptas (4 pts of initial coordinate space)
* pixg (<optional> 8 bpp, for alpha channel, can be null)
* fract (between 0.0 and 1.0, with 0.0 fully transparent
* and 1.0 fully opaque)
* border (of pixels added to capture transformed source pixels)
* Return: pixd, or null on error
*
* Notes:
* (1) The alpha channel is transformed separately from pixs,
* and aligns with it, being fully transparent outside the
* boundary of the transformed pixs. For pixels that are fully
* transparent, a blending function like pixBlendWithGrayMask()
* will give zero weight to corresponding pixels in pixs.
* (2) If pixg is NULL, it is generated as an alpha layer that is
* partially opaque, using @fract. Otherwise, it is cropped
* to pixs if required and @fract is ignored. The alpha channel
* in pixs is never used.
* (3) Colormaps are removed.
* (4) When pixs is transformed, it doesn't matter what color is brought
* in because the alpha channel will be transparent (0) there.
* (5) To avoid losing source pixels in the destination, it may be
* necessary to add a border to the source pix before doing
* the projective transformation. This can be any non-negative
* number.
* (6) The input @ptad and @ptas are in a coordinate space before
* the border is added. Internally, we compensate for this
* before doing the projective transform on the image after
* the border is added.
* (7) The default setting for the border values in the alpha channel
* is 0 (transparent) for the outermost ring of pixels and
* (0.5 * fract * 255) for the second ring. When blended over
* a second image, this
* (a) shrinks the visible image to make a clean overlap edge
* with an image below, and
* (b) softens the edges by weakening the aliasing there.
* Use l_setAlphaMaskBorder() to change these values.
*/
PIX *
pixProjectivePtaWithAlpha(PIX *pixs,
PTA *ptad,
PTA *ptas,
PIX *pixg,
l_float32 fract,
l_int32 border)
{
l_int32 ws, hs, d;
PIX *pixd, *pixb1, *pixb2, *pixg2, *pixga;
PTA *ptad2, *ptas2;
PROCNAME("pixProjectivePtaWithAlpha");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
pixGetDimensions(pixs, &ws, &hs, &d);
if (d != 32 && pixGetColormap(pixs) == NULL)
return (PIX *)ERROR_PTR("pixs not cmapped or 32 bpp", procName, NULL);
if (pixg && pixGetDepth(pixg) != 8) {
L_WARNING("pixg not 8 bpp; using @fract transparent alpha", procName);
pixg = NULL;
}
if (!pixg && (fract < 0.0 || fract > 1.0)) {
L_WARNING("invalid fract; using 1.0 (fully transparent)", procName);
fract = 1.0;
}
if (!pixg && fract == 0.0)
L_WARNING("fully opaque alpha; image will not be blended", procName);
if (!ptad)
return (PIX *)ERROR_PTR("ptad not defined", procName, NULL);
if (!ptas)
return (PIX *)ERROR_PTR("ptas not defined", procName, NULL);
/* Add border; the color doesn't matter */
pixb1 = pixAddBorder(pixs, border, 0);
/* Transform the ptr arrays to work on the bordered image */
ptad2 = ptaTransform(ptad, border, border, 1.0, 1.0);
ptas2 = ptaTransform(ptas, border, border, 1.0, 1.0);
/* Do separate projective transform of rgb channels of pixs
* and of pixg */
pixd = pixProjectivePtaColor(pixb1, ptad2, ptas2, 0);
if (!pixg) {
pixg2 = pixCreate(ws, hs, 8);
if (fract == 1.0)
pixSetAll(pixg2);
else
pixSetAllArbitrary(pixg2, (l_int32)(255.0 * fract));
}
else
pixg2 = pixResizeToMatch(pixg, NULL, ws, hs);
if (ws > 10 && hs > 10) { /* see note 7 */
pixSetBorderRingVal(pixg2, 1,
(l_int32)(255.0 * fract * AlphaMaskBorderVals[0]));
pixSetBorderRingVal(pixg2, 2,
(l_int32)(255.0 * fract * AlphaMaskBorderVals[1]));
}
pixb2 = pixAddBorder(pixg2, border, 0); /* must be black border */
pixga = pixProjectivePtaGray(pixb2, ptad2, ptas2, 0);
pixSetRGBComponent(pixd, pixga, L_ALPHA_CHANNEL);
pixDestroy(&pixg2);
pixDestroy(&pixb1);
pixDestroy(&pixb2);
pixDestroy(&pixga);
ptaDestroy(&ptad2);
ptaDestroy(&ptas2);
return pixd;
}
/*!
* pixRotateWithAlpha()
*
* Input: pixs (32 bpp rgb or cmapped)
* angle (radians; clockwise is positive)
* pixg (<optional> 8 bpp, can be null)
* fract (between 0.0 and 1.0, with 0.0 fully transparent
* and 1.0 fully opaque)
* Return: pixd (32 bpp rgba), or null on error
*
* Notes:
* (1) The alpha channel is transformed separately from pixs,
* and aligns with it, being fully transparent outside the
* boundary of the transformed pixs. For pixels that are fully
* transparent, a blending function like pixBlendWithGrayMask()
* will give zero weight to corresponding pixels in pixs.
* (2) Rotation is about the center of the image; for very small
* rotations, just return a clone. The dest is automatically
* expanded so that no image pixels are lost.
* (3) Rotation is by area mapping. It doesn't matter what
* color is brought in because the alpha channel will
* be transparent (black) there.
* (4) If pixg is NULL, it is generated as an alpha layer that is
* partially opaque, using @fract. Otherwise, it is cropped
* to pixs if required and @fract is ignored. The alpha
* channel in pixs is never used.
* (4) Colormaps are removed to 32 bpp.
* (5) The default setting for the border values in the alpha channel
* is 0 (transparent) for the outermost ring of pixels and
* (0.5 * fract * 255) for the second ring. When blended over
* a second image, this
* (a) shrinks the visible image to make a clean overlap edge
* with an image below, and
* (b) softens the edges by weakening the aliasing there.
* Use l_setAlphaMaskBorder() to change these values.
* (6) A subtle use of gamma correction is to remove gamma correction
* before rotation and restore it afterwards. This is done
* by sandwiching this function between a gamma/inverse-gamma
* photometric transform:
* pixt = pixGammaTRCWithAlpha(NULL, pixs, 1.0 / gamma, 0, 255);
* pixd = pixRotateWithAlpha(pixt, angle, NULL, fract);
* pixGammaTRCWithAlpha(pixd, pixd, gamma, 0, 255);
* pixDestroy(&pixt);
* This has the side-effect of producing artifacts in the very
* dark regions.
*
* *** Warning: implicit assumption about RGB component ordering ***
*/
PIX *
pixRotateWithAlpha(PIX *pixs,
l_float32 angle,
PIX *pixg,
l_float32 fract) {
l_int32 ws, hs, d, spp;
PIX *pixd, *pix32, *pixg2, *pixgr;
PROCNAME("pixRotateWithAlpha");
if (!pixs)
return (PIX *) ERROR_PTR("pixs not defined", procName, NULL);
pixGetDimensions(pixs, &ws, &hs, &d);
if (d != 32 && pixGetColormap(pixs) == NULL)
return (PIX *) ERROR_PTR("pixs not cmapped or 32 bpp", procName, NULL);
if (pixg && pixGetDepth(pixg) != 8) {
L_WARNING("pixg not 8 bpp; using @fract transparent alpha\n", procName);
pixg = NULL;
}
if (!pixg && (fract < 0.0 || fract > 1.0)) {
L_WARNING("invalid fract; using fully opaque\n", procName);
fract = 1.0;
}
if (!pixg && fract == 0.0)
L_WARNING("transparent alpha; image will not be blended\n", procName);
/* Make sure input to rotation is 32 bpp rgb, and rotate it */
if (d != 32)
pix32 = pixConvertTo32(pixs);
else
pix32 = pixClone(pixs);
spp = pixGetSpp(pix32);
pixSetSpp(pix32, 3); /* ignore the alpha channel for the rotation */
pixd = pixRotate(pix32, angle, L_ROTATE_AREA_MAP, L_BRING_IN_WHITE, ws, hs);
pixSetSpp(pix32, spp); /* restore initial value in case it's a clone */
pixDestroy(&pix32);
/* Set up alpha layer with a fading border and rotate it */
if (!pixg) {
pixg2 = pixCreate(ws, hs, 8);
if (fract == 1.0)
pixSetAll(pixg2);
else if (fract > 0.0)
pixSetAllArbitrary(pixg2, (l_int32)(255.0 * fract));
} else {
pixg2 = pixResizeToMatch(pixg, NULL, ws, hs);
}
if (ws > 10 && hs > 10) { /* see note 8 */
pixSetBorderRingVal(pixg2, 1,
(l_int32)(255.0 * fract * AlphaMaskBorderVals[0]));
pixSetBorderRingVal(pixg2, 2,
(l_int32)(255.0 * fract * AlphaMaskBorderVals[1]));
}
pixgr = pixRotate(pixg2, angle, L_ROTATE_AREA_MAP,
L_BRING_IN_BLACK, ws, hs);
/* Combine into a 4 spp result */
pixSetRGBComponent(pixd, pixgr, L_ALPHA_CHANNEL);
pixDestroy(&pixg2);
pixDestroy(&pixgr);
return pixd;
}
