Lines Matching refs:alpha
135 /* Handle alpha and tRNS via a background color */
322 * encode the alpha as well as the color channels
356 case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */
363 png_error(png_ptr, "invalid alpha mode");
384 /* And obtain alpha pre-multiplication by composing on black: */
392 "conflicting calls to set alpha mode and background");
831 * premultiplied alpha support; this actually hides an undocumented feature
869 * to alpha channels.
885 * fully transparent palette entry to a full alpha channel--perhaps instead
896 * to expand only the sample depth but not to expand the tRNS to alpha
924 /* Expand tRNS chunks to alpha channels. */
1150 /* If no alpha we can optimize. */
1153 /* Any alpha means background and associative alpha processing is
1154 * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
1170 /* The following code cannot be entered in the alpha pre-multiplication case
1189 /* Invert the alpha channel (in tRNS) unless the pixels are
1201 } /* background expand and (therefore) no alpha association. */
1209 * is any alpha or transparency in the image and simply cancel the
1210 * background and alpha mode stuff if there isn't.
1215 /* If no alpha we can optimize. */
1218 /* Any alpha means background and associative alpha processing is
1219 * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
1237 /* The following code cannot be entered in the alpha pre-multiplication case
1286 } /* background expand and (therefore) no alpha association. */
1332 * png_set_alpha_mode (even if the alpha handling mode isn't required
1397 /* Stripping the alpha channel happens immediately after the 'expand'
1399 * the alpha handling. It has the side effect negating the effect of
1485 * composite (background and alpha) stuff, which can be pretty much all done
1549 * allows pre-multiplication of the alpha channel to be implemented as
2107 /* If adding a true alpha channel not just filler */
2280 shift[channels++] = bit_depth - sig_bits->alpha;
2581 /* This inverts the alpha channel in RGBA */
2602 /* This inverts the alpha channel in RRGGBBAA */
2633 /* This inverts the alpha channel in GA */
2648 /* This inverts the alpha channel in GGAA */
2858 /* Expand grayscale files to RGB, with or without alpha */
2946 /* Reduce RGB files to grayscale, with or without alpha
3195 /* Replace any alpha or transparency with the supplied background color.
3937 /* Gamma correct the image, avoiding the alpha channel. Make sure
4140 /* Encode the alpha channel to the output gamma (the input channel is always
4141 * linear.) Called only with color types that have an alpha channel. Needs the
4161 /* The alpha channel is the last component: */
4180 /* The alpha channel is the last component: */
4380 * expanded transparency value is supplied, an alpha channel is built.
4844 * - Gray + alpha -> composite with gray background and remove alpha bytes,
4853 * - Gray + alpha -> convert to RGB + alpha, composite with background and
4854 * remove alpha bytes (3x float
4888 * do (if there is an alpha channel or transparency.)