diff --git a/include/system/graphics.h b/include/system/graphics.h index 1ac1a0070..529a562f3 100644 --- a/include/system/graphics.h +++ b/include/system/graphics.h @@ -1134,6 +1134,236 @@ typedef enum android_dataspace { } android_dataspace_t; +/* + * Color modes that may be supported by a display. + * + * Definitions: + * Rendering intent generally defines the goal in mapping a source (input) + * color to a destination device color for a given color mode. + * + * It is important to keep in mind three cases where mapping may be applied: + * 1. The source gamut is much smaller than the destination (display) gamut + * 2. The source gamut is much larger than the destination gamut (this will + * ordinarily be handled using colorimetric rendering, below) + * 3. The source and destination gamuts are roughly equal, although not + * completely overlapping + * Also, a common requirement for mappings is that skin tones should be + * preserved, or at least remain natural in appearance. + * + * Colorimetric Rendering Intent (All cases): + * Colorimetric indicates that colors should be preserved. In the case + * that the source gamut lies wholly within the destination gamut or is + * about the same (#1, #3), this will simply mean that no manipulations + * (no saturation boost, for example) are applied. In the case where some + * source colors lie outside the destination gamut (#2, #3), those will + * need to be mapped to colors that are within the destination gamut, + * while the already in-gamut colors remain unchanged. + * + * Non-colorimetric transforms can take many forms. There are no hard + * rules and it's left to the implementation to define. + * Two common intents are described below. + * + * Stretched-Gamut Enhancement Intent (Source < Destination): + * When the destination gamut is much larger than the source gamut (#1), the + * source primaries may be redefined to reflect the full extent of the + * destination space, or to reflect an intermediate gamut. + * Skin-tone preservation would likely be applied. An example might be sRGB + * input displayed on a DCI-P3 capable device, with skin-tone preservation. + * + * Within-Gamut Enhancement Intent (Source >= Destination): + * When the device (destination) gamut is not larger than the source gamut + * (#2 or #3), but the appearance of a larger gamut is desired, techniques + * such as saturation boost may be applied to the source colors. Skin-tone + * preservation may be applied. There is no unique method for within-gamut + * enhancement; it would be defined within a flexible color mode. + * + */ +typedef enum android_color_mode { + + /* + * HAL_COLOR_MODE_DEFAULT is the "native" gamut of the display. + * White Point: Vendor/OEM defined + * Panel Gamma: Vendor/OEM defined (typically 2.2) + * Rendering Intent: Vendor/OEM defined (typically 'enhanced') + */ + HAL_COLOR_MODE_NATIVE = 0, + + /* + * HAL_COLOR_MODE_STANDARD_BT601_625 corresponds with display + * settings that implement the ITU-R Recommendation BT.601 + * or Rec 601. Using 625 line version + * Rendering Intent: Colorimetric + * Primaries: + * x y + * green 0.290 0.600 + * blue 0.150 0.060 + * red 0.640 0.330 + * white (D65) 0.3127 0.3290 + * + * KR = 0.299, KB = 0.114. This adjusts the luminance interpretation + * for RGB conversion from the one purely determined by the primaries + * to minimize the color shift into RGB space that uses BT.709 + * primaries. + * + * Gamma Correction (GC): + * + * if Vlinear < 0.018 + * Vnonlinear = 4.500 * Vlinear + * else + * Vnonlinear = 1.099 * (Vlinear)^(0.45) – 0.099 + */ + HAL_COLOR_MODE_STANDARD_BT601_625 = 1, + + /* + * Primaries: + * x y + * green 0.290 0.600 + * blue 0.150 0.060 + * red 0.640 0.330 + * white (D65) 0.3127 0.3290 + * + * Use the unadjusted KR = 0.222, KB = 0.071 luminance interpretation + * for RGB conversion. + * + * Gamma Correction (GC): + * + * if Vlinear < 0.018 + * Vnonlinear = 4.500 * Vlinear + * else + * Vnonlinear = 1.099 * (Vlinear)^(0.45) – 0.099 + */ + HAL_COLOR_MODE_STANDARD_BT601_625_UNADJUSTED = 2, + + /* + * Primaries: + * x y + * green 0.310 0.595 + * blue 0.155 0.070 + * red 0.630 0.340 + * white (D65) 0.3127 0.3290 + * + * KR = 0.299, KB = 0.114. This adjusts the luminance interpretation + * for RGB conversion from the one purely determined by the primaries + * to minimize the color shift into RGB space that uses BT.709 + * primaries. + * + * Gamma Correction (GC): + * + * if Vlinear < 0.018 + * Vnonlinear = 4.500 * Vlinear + * else + * Vnonlinear = 1.099 * (Vlinear)^(0.45) – 0.099 + */ + HAL_COLOR_MODE_STANDARD_BT601_525 = 3, + + /* + * Primaries: + * x y + * green 0.310 0.595 + * blue 0.155 0.070 + * red 0.630 0.340 + * white (D65) 0.3127 0.3290 + * + * Use the unadjusted KR = 0.212, KB = 0.087 luminance interpretation + * for RGB conversion (as in SMPTE 240M). + * + * Gamma Correction (GC): + * + * if Vlinear < 0.018 + * Vnonlinear = 4.500 * Vlinear + * else + * Vnonlinear = 1.099 * (Vlinear)^(0.45) – 0.099 + */ + HAL_COLOR_MODE_STANDARD_BT601_525_UNADJUSTED = 4, + + /* + * HAL_COLOR_MODE_REC709 corresponds with display settings that implement + * the ITU-R Recommendation BT.709 / Rec. 709 for high-definition television. + * Rendering Intent: Colorimetric + * Primaries: + * x y + * green 0.300 0.600 + * blue 0.150 0.060 + * red 0.640 0.330 + * white (D65) 0.3127 0.3290 + * + * HDTV REC709 Inverse Gamma Correction (IGC): V represents normalized + * (with [0 to 1] range) value of R, G, or B. + * + * if Vnonlinear < 0.081 + * Vlinear = Vnonlinear / 4.5 + * else + * Vlinear = ((Vnonlinear + 0.099) / 1.099) ^ (1/0.45) + * + * HDTV REC709 Gamma Correction (GC): + * + * if Vlinear < 0.018 + * Vnonlinear = 4.5 * Vlinear + * else + * Vnonlinear = 1.099 * (Vlinear) ^ 0.45 – 0.099 + */ + HAL_COLOR_MODE_STANDARD_BT709 = 5, + + /* + * HAL_COLOR_MODE_DCI_P3 corresponds with display settings that implement + * SMPTE EG 432-1 and SMPTE RP 431-2 + * Rendering Intent: Colorimetric + * Primaries: + * x y + * green 0.265 0.690 + * blue 0.150 0.060 + * red 0.680 0.320 + * white (D65) 0.3127 0.3290 + * + * Gamma: 2.2 + */ + HAL_COLOR_MODE_DCI_P3 = 6, + + /* + * HAL_COLOR_MODE_SRGB corresponds with display settings that implement + * the sRGB color space. Uses the same primaries as ITU-R Recommendation + * BT.709 + * Rendering Intent: Colorimetric + * Primaries: + * x y + * green 0.300 0.600 + * blue 0.150 0.060 + * red 0.640 0.330 + * white (D65) 0.3127 0.3290 + * + * PC/Internet (sRGB) Inverse Gamma Correction (IGC): + * + * if Vnonlinear ≤ 0.03928 + * Vlinear = Vnonlinear / 12.92 + * else + * Vlinear = ((Vnonlinear + 0.055)/1.055) ^ 2.4 + * + * PC/Internet (sRGB) Gamma Correction (GC): + * + * if Vlinear ≤ 0.0031308 + * Vnonlinear = 12.92 * Vlinear + * else + * Vnonlinear = 1.055 * (Vlinear)^(1/2.4) – 0.055 + */ + HAL_COLOR_MODE_SRGB = 7, + + /* + * HAL_COLOR_MODE_ADOBE_RGB corresponds with the RGB color space developed + * by Adobe Systems, Inc. in 1998. + * Rendering Intent: Colorimetric + * Primaries: + * x y + * green 0.210 0.710 + * blue 0.150 0.060 + * red 0.640 0.330 + * white (D65) 0.3127 0.3290 + * + * Gamma: 2.2 + */ + HAL_COLOR_MODE_ADOBE_RGB = 8 + +} android_color_mode_t; + /* * Color transforms that may be applied by hardware composer to the whole * display.