- {/* From: tiff-4.0.x/libtiff/tif_getimage.c : */
- uint16* sampleinfo;
- uint16 extrasamples;
-
- TIFFGetFieldDefaulted(tif, TIFFTAG_EXTRASAMPLES,
- &extrasamples, &sampleinfo);
-
- if (extrasamples >= 1) {
- switch (sampleinfo[0]) {
- case EXTRASAMPLE_UNSPECIFIED:
- /* Workaround for some images without correct info about alpha channel
- */
- if (tiSpp > 3) {
- has_alpha = 1;
- }
- break;
-
- case EXTRASAMPLE_ASSOCALPHA: /* data pre-multiplied */
- case EXTRASAMPLE_UNASSALPHA: /* data not pre-multiplied */
- has_alpha = 1;
- break;
- }
- } else /* extrasamples == 0 */
- if (tiSpp == 4 || tiSpp == 2) {
- has_alpha = 1;
- }
- }
-