Data Space

Adobe RGB.

Uses full range, gamma 2.2 transfer and Adobe RGB standard.

Note: Application is responsible for gamma encoding the data as a 2.2 gamma encoding is not supported in HW.

ITU-R Recommendation 2020 (BT.2020)

Ultra High-definition television

Uses full range, SMPTE 170M transfer and BT2020 standard.

Hybrid Log Gamma encoding.

Uses full range, hybrid log gamma transfer and BT2020 standard.

ITU Hybrid Log Gamma encoding.

Uses limited range, hybrid log gamma transfer and BT2020 standard.

ITU-R Recommendation 2020 (BT.2020)

Ultra High-definition television

Uses limited range, SMPTE 2084 (PQ) transfer and BT2020 standard.

ITU-R Recommendation 2020 (BT.2020)

Ultra High-definition television

Uses full range, SMPTE 2084 (PQ) transfer and BT2020 standard.

ITU-R Recommendation 601 (BT.601) - 525-line.

Standard-definition television, 525 Lines (NTSC)

Uses limited range, SMPTE 170M transfer and BT.601_525 standard.

ITU-R Recommendation 601 (BT.601) - 625-line.

Standard-definition television, 625 Lines (PAL)

Uses limited range, SMPTE 170M transfer and BT.601_625 standard.

ITU-R Recommendation 709 (BT.709)

High-definition television

Uses limited range, SMPTE 170M transfer and BT.709 standard.

SMPTE EG 432-1 and SMPTE RP 431-2.

Digital Cinema DCI-P3

Uses full range, gamma 2.6 transfer and D65 DCI-P3 standard.

Note: Application is responsible for gamma encoding the data as a 2.6 gamma encoding is not supported in HW.

Depth.

This value is valid with formats HAL_PIXEL_FORMAT_Y16 and HAL_PIXEL_FORMAT_BLOB.

Display P3.

Uses full range, sRGB transfer and D65 DCI-P3 standard.

ISO 16684-1:2011(E) Dynamic Depth.

Embedded depth metadata following the dynamic depth specification.

JPEG File Interchange Format (JFIF)

Same model as BT.601-625, but all values (Y, Cb, Cr) range from 0 to 255.

Uses full range, SMPTE 170M transfer and BT.601_625 standard.

Extended range is used for scRGB.

Intended for use with floating point pixel formats. [0.0 - 1.0] is the standard sRGB space. Values outside the range 0.0 - 1.0 can encode color outside the sRGB gamut. Used to blend / merge multiple dataspaces on a single display.

Full range uses all values for Y, Cb and Cr from 0 to 2^b-1, where b is the bit depth of the color format.

Limited range uses values 16/256*2^b to 235/256*2^b for Y, and 1/16*2^b to 15/16*2^b for Cb, Cr, R, G and B, where b is the bit depth of the color format.

E.g. For 8-bit-depth formats: Luma (Y) samples should range from 16 to 235, inclusive Chroma (Cb, Cr) samples should range from 16 to 240, inclusive

For 10-bit-depth formats: Luma (Y) samples should range from 64 to 940, inclusive Chroma (Cb, Cr) samples should range from 64 to 960, inclusive

Range aspect.

Defines the range of values corresponding to the unit range of 0-1. This is defined for YCbCr only, but can be expanded to RGB space.

Range is unknown or are determined by the application.

Implementations shall use the following suggested ranges:

All YCbCr formats: limited range. All RGB or RGBA formats (including RAW and Bayer): full range. All Y formats: full range

For all other formats range is undefined, and implementations should use an appropriate range for the data represented.

scRGB

The red, green, and blue components are stored in extended sRGB space, and gamma-encoded using the SRGB transfer function.

The values are floating point. A pixel value of 1.0, 1.0, 1.0 corresponds to sRGB white (D65) at 80 nits. Values beyond the range [0.0 - 1.0] would correspond to other colors spaces and/or HDR content.

Uses extended range, sRGB transfer and BT.709 standard.

scRGB linear encoding

The red, green, and blue components are stored in extended sRGB space, but are linear, not gamma-encoded.

The values are floating point. A pixel value of 1.0, 1.0, 1.0 corresponds to sRGB white (D65) at 80 nits. Values beyond the range [0.0 - 1.0] would correspond to other colors spaces and/or HDR content.

Uses extended range, linear transfer and BT.709 standard.

sRGB gamma encoding

The red, green and blue components are stored in sRGB space, and converted to linear space when read, using the SRGB transfer function for each of the R, G and B components. When written, the inverse transformation is performed.

The alpha component, if present, is always stored in linear space and is left unmodified when read or written.

Uses full range, sRGB transfer BT.709 standard.

sRGB linear encoding

The red, green, and blue components are stored in sRGB space, but are linear, not gamma-encoded. The RGB primaries and the white point are the same as BT.709.

The values are encoded using the full range ([0,255] for 8-bit) for all components.

Uses full range, linear transfer and BT.709 standard.

Adobe RGB.

Primaries:       x       y
 green           0.210   0.710
 blue            0.150   0.060
 red             0.640   0.330
 white (D65)     0.3127  0.3290

Primaries:       x       y
 green           0.170   0.797
 blue            0.131   0.046
 red             0.708   0.292
 white (D65)     0.3127  0.3290

Use the unadjusted KR = 0.2627, KB = 0.0593 luminance interpretation for RGB conversion.

Primaries:       x       y
 green           0.170   0.797
 blue            0.131   0.046
 red             0.708   0.292
 white (D65)     0.3127  0.3290

Use the unadjusted KR = 0.2627, KB = 0.0593 luminance interpretation for RGB conversion using the linear domain.

Primaries:       x      y
 green           0.21   0.71
 blue            0.14   0.08
 red             0.67   0.33
 white (C)       0.310  0.316

Use the unadjusted KR = 0.30, KB = 0.11 luminance interpretation for RGB conversion.

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.

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).

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.

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.

Primaries:       x       y
 green           0.300   0.600
 blue            0.150   0.060
 red             0.640   0.330
 white (D65)     0.3127  0.3290

Use the unadjusted KR = 0.2126, KB = 0.0722 luminance interpretation for RGB conversion.

SMPTE EG 432-1 and SMPTE RP 431-2.

(DCI-P3)

Primaries:       x       y
 green           0.265   0.690
 blue            0.150   0.060
 red             0.680   0.320
 white (D65)     0.3127  0.3290

Primaries:       x       y
 green           0.243   0.692
 blue            0.145   0.049
 red             0.681   0.319
 white (C)       0.310   0.316

Use the unadjusted KR = 0.254, KB = 0.068 luminance interpretation for RGB conversion.

Color-description aspects.

The following aspects define various characteristics of the color specification. These represent bitfields, so that a data space value can specify each of them independently. Standard aspect

Defines the chromaticity coordinates of the source primaries in terms of the CIE 1931 definition of x and y specified in ISO 11664-1.

Chromacity coordinates are unknown or are determined by the application.

Implementations shall use the following suggested standards:

All YCbCr formats: BT709 if size is 720p or larger (since most video content is letterboxed this corresponds to width is 1280 or greater, or height is 720 or greater). BT601_625 if size is smaller than 720p or is JPEG. All RGB formats: BT709.

For all other formats standard is undefined, and implementations should use an appropriate standard for the data represented.

Display gamma 2.2.

Transfer characteristic curve:
E = L ^ (1/2.2)
    L - luminance of image 0 <= L <= 1 for conventional colorimetry
    E - corresponding electrical signal

Display gamma 2.6.

Transfer characteristic curve:
E = L ^ (1/2.6)
    L - luminance of image 0 <= L <= 1 for conventional colorimetry
    E - corresponding electrical signal

Display gamma 2.8.

Transfer characteristic curve:
E = L ^ (1/2.8)
    L - luminance of image 0 <= L <= 1 for conventional colorimetry
    E - corresponding electrical signal

ARIB STD-B67 Hybrid Log Gamma.

Transfer characteristic curve:
 E = r * L^0.5                 for 0 <= L <= 1
   = a * ln(L - b) + c         for 1 < L
 a = 0.17883277
 b = 0.28466892
 c = 0.55991073
 r = 0.5
     L - luminance of image 0 <= L for HDR colorimetry. L = 1 corresponds
         to reference white level of 100 cd/m2
     E - corresponding electrical signal

Linear transfer.

Transfer characteristic curve:
E = L
    L - luminance of image 0 <= L <= 1 for conventional colorimetry
    E - corresponding electrical signal

Transfer aspect.

Transfer characteristics are the opto-electronic transfer characteristic at the source as a function of linear optical intensity (luminance).

For digital signals, E corresponds to the recorded value. Normally, the transfer function is applied in RGB space to each of the R, G and B components independently. This may result in color shift that can be minized by applying the transfer function in Lab space only for the L component. Implementation may apply the transfer function in RGB space for all pixel formats if desired.

SMPTE 170M transfer.

Transfer characteristic curve:
E = 1.099 * L ^ 0.45 - 0.099  for 0.018 <= L <= 1
  = 4.500 * L                 for 0 <= L < 0.018
    L - luminance of image 0 <= L <= 1 for conventional colorimetry
    E - corresponding electrical signal

sRGB transfer.

Transfer characteristic curve:
E = 1.055 * L^(1/2.4) - 0.055  for 0.0031308 <= L <= 1
  = 12.92 * L                  for 0 <= L < 0.0031308
    L - luminance of image 0 <= L <= 1 for conventional colorimetry
    E - corresponding electrical signal

SMPTE ST 2084 (Dolby Perceptual Quantizer).

Transfer characteristic curve:
E = ((c1 + c2 * L^n) / (1 + c3 * L^n)) ^ m
c1 = c3 - c2 + 1 = 3424 / 4096 = 0.8359375
c2 = 32 * 2413 / 4096 = 18.8515625
c3 = 32 * 2392 / 4096 = 18.6875
m = 128 * 2523 / 4096 = 78.84375
n = 0.25 * 2610 / 4096 = 0.1593017578125
    L - luminance of image 0 <= L <= 1 for HDR colorimetry.
        L = 1 corresponds to 10000 cd/m2
    E - corresponding electrical signal

Transfer characteristics are unknown or are determined by the application.

Implementations should use the following transfer functions:

For YCbCr formats: use ADATASPACE_TRANSFER_SMPTE_170M For RGB formats: use ADATASPACE_TRANSFER_SRGB

For all other formats transfer function is undefined, and implementations should use an appropriate standard for the data represented.

Default-assumption data space, when not explicitly specified.

It is safest to assume the buffer is an image with sRGB primaries and encoding ranges, but the consumer and/or the producer of the data may simply be using defaults. No automatic gamma transform should be expected, except for a possible display gamma transform when drawn to a screen.