ADataSpace

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.

scRGB linear encoding:

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

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.

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.

Use full range and BT.709 standard.

scRGB:

The red, green, and blue components are stored in extended sRGB space, and gamma-encoded using the SRGB transfer function. The RGB primaries and the white point are the same as BT.709.

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.

Display P3

Use same primaries and white-point as DCI-P3 but sRGB transfer function.

ITU-R Recommendation 2020 (BT.2020)

Ultra High-definition television

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