Lines Matching refs:gamma
286 * the user to obtain a gamma-corrected palette, for example.
1108 /* We don't handle background color or gamma transformation or quantizing.
1189 /* Optional call to gamma correct and add the background to the palette
1236 # define P_sRGB 1 /* 8-bit encoded to sRGB gamma */
1238 # define P_FILE 3 /* 8-bit encoded to file gamma, not sRGB or linear */
1270 png_fixed_point gamma_to_linear; /* For P_FILE, reciprocal of gamma */
1356 /* Is the given gamma significantly different from sRGB? The test is the same
1357 * one used in pngrtran.c when deciding whether to do gamma correction. The
1359 * file sRGB gamma is 2.2
1366 /* An uninitialized gamma is assumed to be sRGB for the simplified API. */
1640 png_fixed_point g = display->image->opaque->png_ptr->colorspace.gamma;
1747 /* Update the cache with whether the file gamma is significantly different
2123 /* Default the input file gamma if required - this is necessary because
2124 * libpng assumes that if no gamma information is present the data is in the
2125 * output format, but the simplified API deduces the gamma from the input
2137 png_ptr->colorspace.gamma = PNG_GAMMA_LINEAR;
2140 png_ptr->colorspace.gamma = PNG_GAMMA_sRGB_INVERSE;
2182 * gamma correction flag is 0) or 0..255 scaled file encoded values
2183 * (if the function must gamma correct them).
2189 * have non-gamma corrected values to do tRNS handling.
2193 P_FILE/*8-bit with file gamma*/);
2222 /* The 16-bit input values can be converted directly to 8-bit gamma
2285 0/*gamma: not used*/);
2394 0/*gamma: not used*/);
2528 /* Ideally this code would use libpng to do the gamma correction,
2530 * libpng bug in gamma+compose+rgb-to-gray (the double gamma
2531 * correction bug). Fix this by dropping the gamma correction in
2534 * alternative of double gamma correction.
2538 png_gamma_not_sRGB(png_ptr->colorspace.gamma) != 0)
2571 png_ptr->colorspace.gamma)); /* now P_FILE */
2603 0/*gamma: not used*/);
2752 0/*gamma: not used*/);
3357 * PNG_COMPOSITE code performs gamma correction, so we get double gamma
3375 * libpng doing rgb to gray and gamma correction but background processing
3654 int do_local_background = 0; /* to avoid double gamma correction bug */
3681 * background/pre-multiplication if there is also significant gamma
3683 * the code only supports one transform doing the gamma correction.
3703 /* Set the gamma appropriately, linear for 16-bit input, sRGB otherwise.
3714 /* Call png_set_alpha_mode to set the default for the input gamma; the
3715 * output gamma is set by a second call below.
3740 /* If 'do_local_background' is set check for the presence of gamma
3751 * gamma correction, the screen gamma hasn't been set on png_struct
3752 * yet; it's set below. png_struct::gamma, however, is set to the
3755 if (png_muldiv(>est, output_gamma, png_ptr->colorspace.gamma,
3820 0/*gamma: not used*/);
3871 * sets the output gamma.
