diff options
author | Niklas Haas <git@nand.wakku.to> | 2016-03-29 18:58:58 +0200 |
---|---|---|
committer | wm4 <wm4@nowhere> | 2016-04-01 10:27:32 +0200 |
commit | a3361ad0ce683bc914d56faa946522d1050eaec7 (patch) | |
tree | 67c01d74cf0a9106a9d50dff80954faa3f9b9358 /video/out/opengl | |
parent | 2dcf18c0c01282f0f0e72423038a78c1fc938b02 (diff) |
gl_lcms: choose BT.1886 gamma per-channel
This makes the black point closer (chromatically) to the white point, by
ensuring channels keep their consistent brightness ratios as they go
down to zero.
I also raised the 3DLUT version as this changes semantics and is a
separate commit from the previous one.
Diffstat (limited to 'video/out/opengl')
-rw-r--r-- | video/out/opengl/lcms.c | 59 |
1 files changed, 35 insertions, 24 deletions
diff --git a/video/out/opengl/lcms.c b/video/out/opengl/lcms.c index 8f6b40830a..7db8da6f70 100644 --- a/video/out/opengl/lcms.c +++ b/video/out/opengl/lcms.c @@ -193,44 +193,49 @@ static cmsHPROFILE get_vid_profile(cmsContext cms, cmsHPROFILE disp_profile, .Blue = {csp.blue.x, csp.blue.y, 1.0}, }; - cmsToneCurve *tonecurve = NULL; + cmsToneCurve *tonecurve[3] = {0}; switch (trc) { - case MP_CSP_TRC_LINEAR: tonecurve = cmsBuildGamma(cms, 1.0); break; - case MP_CSP_TRC_GAMMA18: tonecurve = cmsBuildGamma(cms, 1.8); break; - case MP_CSP_TRC_GAMMA22: tonecurve = cmsBuildGamma(cms, 2.2); break; - case MP_CSP_TRC_GAMMA28: tonecurve = cmsBuildGamma(cms, 2.8); break; + case MP_CSP_TRC_LINEAR: tonecurve[0] = cmsBuildGamma(cms, 1.0); break; + case MP_CSP_TRC_GAMMA18: tonecurve[0] = cmsBuildGamma(cms, 1.8); break; + case MP_CSP_TRC_GAMMA22: tonecurve[0] = cmsBuildGamma(cms, 2.2); break; + case MP_CSP_TRC_GAMMA28: tonecurve[0] = cmsBuildGamma(cms, 2.8); break; case MP_CSP_TRC_SRGB: // Values copied from Little-CMS - tonecurve = cmsBuildParametricToneCurve(cms, 4, + tonecurve[0] = cmsBuildParametricToneCurve(cms, 4, (double[5]){2.40, 1/1.055, 0.055/1.055, 1/12.92, 0.04045}); break; case MP_CSP_TRC_PRO_PHOTO: - tonecurve = cmsBuildParametricToneCurve(cms, 4, + tonecurve[0] = cmsBuildParametricToneCurve(cms, 4, (double[5]){1.8, 1.0, 0.0, 1/16.0, 0.03125}); break; case MP_CSP_TRC_BT_1886: { // To build an appropriate BT.1886 transformation we need access to // the display's black point, so we use the reverse mappings - cmsHPROFILE xyz_profile = cmsCreateXYZProfileTHR(cms); - cmsHTRANSFORM rgb2xyz = cmsCreateTransformTHR(cms, - disp_profile, TYPE_RGB_16, xyz_profile, TYPE_XYZ_DBL, + cmsToneCurve *linear = cmsBuildGamma(cms, 1.0); + cmsHPROFILE rev_profile = cmsCreateRGBProfileTHR(cms, &wp_xyY, &prim_xyY, + (cmsToneCurve*[3]){linear, linear, linear}); + cmsHTRANSFORM disp2src = cmsCreateTransformTHR(cms, + disp_profile, TYPE_RGB_16, rev_profile, TYPE_RGB_DBL, INTENT_RELATIVE_COLORIMETRIC, 0); - cmsCloseProfile(xyz_profile); - if (!rgb2xyz) + cmsFreeToneCurve(linear); + cmsCloseProfile(rev_profile); + if (!disp2src) return false; - uint64_t black[3] = {0}; - cmsCIEXYZ disp_black; - cmsDoTransform(rgb2xyz, black, &disp_black, 1); + uint64_t disp_black[3] = {0}; + double src_black[3]; + cmsDoTransform(disp2src, disp_black, src_black, 1); - // Build the parametric BT.1886 transfer curve - const double gamma = 2.40; - double binv = pow(disp_black.Y, 1.0/gamma); - tonecurve = cmsBuildParametricToneCurve(cms, 6, - (double[4]){gamma, 1.0 - binv, binv, 0.0}); + // Build the parametric BT.1886 transfer curve, one per channel + for (int i = 0; i < 3; i++) { + const double gamma = 2.40; + double binv = pow(src_black[i], 1.0/gamma); + tonecurve[i] = cmsBuildParametricToneCurve(cms, 6, + (double[4]){gamma, 1.0 - binv, binv, 0.0}); + } break; } @@ -238,12 +243,18 @@ static cmsHPROFILE get_vid_profile(cmsContext cms, cmsHPROFILE disp_profile, abort(); } - if (!tonecurve) + if (!tonecurve[0]) return false; + if (!tonecurve[1]) tonecurve[1] = tonecurve[0]; + if (!tonecurve[2]) tonecurve[2] = tonecurve[0]; + cmsHPROFILE *vid_profile = cmsCreateRGBProfileTHR(cms, &wp_xyY, &prim_xyY, - (cmsToneCurve*[3]){tonecurve, tonecurve, tonecurve}); - cmsFreeToneCurve(tonecurve); + tonecurve); + + if (tonecurve[2] != tonecurve[0]) cmsFreeToneCurve(tonecurve[2]); + if (tonecurve[1] != tonecurve[0]) cmsFreeToneCurve(tonecurve[1]); + cmsFreeToneCurve(tonecurve[0]); return vid_profile; } @@ -271,7 +282,7 @@ bool gl_lcms_get_lut3d(struct gl_lcms *p, struct lut3d **result_lut3d, // because we may change the parameter in the future or make it // customizable, same for the primaries. char *cache_info = talloc_asprintf(tmp, - "ver=1.2, intent=%d, size=%dx%dx%d, prim=%d, trc=%d\n", + "ver=1.3, intent=%d, size=%dx%dx%d, prim=%d, trc=%d\n", p->opts.intent, s_r, s_g, s_b, prim, trc); uint8_t hash[32]; |