bool TessPDFRenderer::imageToPDFObj(Pix *pix,
char *filename,
long int objnum,
char **pdf_object,
long int *pdf_object_size) {
size_t n;
char b0[kBasicBufSize];
char b1[kBasicBufSize];
char b2[kBasicBufSize];
if (!pdf_object_size || !pdf_object)
return false;
*pdf_object = nullptr;
*pdf_object_size = 0;
if (!filename)
return false;
L_Compressed_Data *cid = nullptr;
const int kJpegQuality = 85;
int format, sad;
findFileFormat(filename, &format);
if (pixGetSpp(pix) == 4 && format == IFF_PNG) {
Pix *p1 = pixAlphaBlendUniform(pix, 0xffffff00);
sad = pixGenerateCIData(p1, L_FLATE_ENCODE, 0, 0, &cid);
pixDestroy(&p1);
} else {
sad = l_generateCIDataForPdf(filename, pix, kJpegQuality, &cid);
}
if (sad || !cid) {
l_CIDataDestroy(&cid);
return false;
}
const char *group4 = "";
const char *filter;
switch(cid->type) {
case L_FLATE_ENCODE:
filter = "/FlateDecode";
break;
case L_JPEG_ENCODE:
filter = "/DCTDecode";
break;
case L_G4_ENCODE:
filter = "/CCITTFaxDecode";
group4 = " /K -1\n";
break;
case L_JP2K_ENCODE:
filter = "/JPXDecode";
break;
default:
l_CIDataDestroy(&cid);
return false;
}
// Maybe someday we will accept RGBA but today is not that day.
// It requires creating an /SMask for the alpha channel.
// http://stackoverflow.com/questions/14220221
const char *colorspace;
if (cid->ncolors > 0) {
n = snprintf(b0, sizeof(b0),
" /ColorSpace [ /Indexed /DeviceRGB %d %s ]\n",
cid->ncolors - 1, cid->cmapdatahex);
if (n >= sizeof(b0)) {
l_CIDataDestroy(&cid);
return false;
}
colorspace = b0;
} else {
switch (cid->spp) {
case 1:
colorspace = " /ColorSpace /DeviceGray\n";
break;
case 3:
colorspace = " /ColorSpace /DeviceRGB\n";
break;
default:
l_CIDataDestroy(&cid);
return false;
}
}
int predictor = (cid->predictor) ? 14 : 1;
// IMAGE
n = snprintf(b1, sizeof(b1),
"%ld 0 obj\n"
"<<\n"
" /Length %ld\n"
" /Subtype /Image\n",
objnum, (unsigned long) cid->nbytescomp);
if (n >= sizeof(b1)) {
l_CIDataDestroy(&cid);
return false;
}
n = snprintf(b2, sizeof(b2),
" /Width %d\n"
" /Height %d\n"
" /BitsPerComponent %d\n"
" /Filter %s\n"
" /DecodeParms\n"
" <<\n"
" /Predictor %d\n"
" /Colors %d\n"
"%s"
" /Columns %d\n"
" /BitsPerComponent %d\n"
" >>\n"
">>\n"
"stream\n",
cid->w, cid->h, cid->bps, filter, predictor, cid->spp,
group4, cid->w, cid->bps);
if (n >= sizeof(b2)) {
l_CIDataDestroy(&cid);
return false;
}
const char *b3 =
"endstream\n"
"endobj\n";
size_t b1_len = strlen(b1);
size_t b2_len = strlen(b2);
size_t b3_len = strlen(b3);
size_t colorspace_len = strlen(colorspace);
*pdf_object_size =
b1_len + colorspace_len + b2_len + cid->nbytescomp + b3_len;
*pdf_object = new char[*pdf_object_size];
char *p = *pdf_object;
memcpy(p, b1, b1_len);
p += b1_len;
memcpy(p, colorspace, colorspace_len);
p += colorspace_len;
memcpy(p, b2, b2_len);
p += b2_len;
memcpy(p, cid->datacomp, cid->nbytescomp);
p += cid->nbytescomp;
memcpy(p, b3, b3_len);
l_CIDataDestroy(&cid);
return true;
}
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 i, spp;
l_uint32 bval, wval;
PIX *pixs, *pix1, *pix2, *pix3, *pixd;
PIXA *pixa;
L_REGPARAMS *rp;
if (regTestSetup(argc, argv, &rp))
return 1;
/* Scale each image and add a white boundary */
pixa = pixaCreate(setsize);
for (i = 0; i < setsize; i++) {
pixs = pixRead(fnames[i]);
spp = pixGetSpp(pixs);
pixGetBlackOrWhiteVal(pixs, L_GET_WHITE_VAL, &wval);
pixGetBlackOrWhiteVal(pixs, L_GET_BLACK_VAL, &bval);
fprintf(stderr, "d = %d, spp = %d, bval = %x, wval = %x\n",
pixGetDepth(pixs), spp, bval, wval);
if (spp == 4) /* remove alpha, using white background */
pix1 = pixAlphaBlendUniform(pixs, wval);
else
pix1 = pixClone(pixs);
pix2 = pixScaleToSize(pix1, 150, 150);
pixGetBlackOrWhiteVal(pix2, L_GET_WHITE_VAL, &wval);
pix3 = pixAddBorderGeneral(pix2, 30, 30, 20, 20, wval);
pixaAddPix(pixa, pix3, L_INSERT);
pixDestroy(&pixs);
pixDestroy(&pix1);
pixDestroy(&pix2);
}
pixd = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 1, 30, 0);
regTestWritePixAndCheck(rp, pixd, IFF_PNG);
pixDisplayWithTitle(pixd, 0, 100, NULL, rp->display);
pixDestroy(&pixd);
pixaDestroy(&pixa);
/* Scale each image and add a black boundary */
pixa = pixaCreate(setsize);
for (i = 0; i < setsize; i++) {
pixs = pixRead(fnames[i]);
spp = pixGetSpp(pixs);
pixGetBlackOrWhiteVal(pixs, L_GET_WHITE_VAL, &wval);
pixGetBlackOrWhiteVal(pixs, L_GET_BLACK_VAL, &bval);
fprintf(stderr, "d = %d, spp = %d, bval = %x, wval = %x\n",
pixGetDepth(pixs), spp, bval, wval);
if (spp == 4) /* remove alpha, using white background */
pix1 = pixAlphaBlendUniform(pixs, wval);
else
pix1 = pixClone(pixs);
pix2 = pixScaleToSize(pix1, 150, 150);
pixGetBlackOrWhiteVal(pixs, L_GET_BLACK_VAL, &bval);
pix3 = pixAddBorderGeneral(pix2, 30, 30, 20, 20, bval);
pixaAddPix(pixa, pix3, L_INSERT);
pixDestroy(&pixs);
pixDestroy(&pix1);
pixDestroy(&pix2);
}
pixd = pixaDisplayTiledInRows(pixa, 32, 1200, 1.0, 0, 30, 0);
regTestWritePixAndCheck(rp, pixd, IFF_PNG);
pixDisplayWithTitle(pixd, 1000, 100, NULL, rp->display);
pixDestroy(&pixd);
pixaDestroy(&pixa);
return regTestCleanup(rp);
}
