Recommended HDR Texture Formats

Attributes of various HDR texture formats

The following table details various attributes of HDR suitable texture formats:

Table 1. HDR suitable texture formats

Texture Format

Bandwidth Cost

USC Cost

Filtering

Precision

Alpha

RGB10A2

Same as RGBA8

None

Hardware accelerated, slightly slower than RGBA8

RGB channels have greater precision over RGBA8 at the cost of alpha precision

Supports alpha - only four unique values

RGBA16F

2x RGBA8

None

Hardware accelerated but performs at half the rate of RGBA8

Far greater precision than RGBA8 - 216 values per channel

Supports alpha

RG11B10F

2x RGBA8

(internally stored as RGBA16F)

None

Hardware accelerated but performs at half the rate of RGBA8

Same as RGBA16F

Does not have an alpha channel

RGBA32F

4x RGBA8

None

Hardware accelerated but performs at quarter the rate of RGBA8 and only supports nearest sampling

Vastly greater precision than any other format - 232 values per channel

Supports alpha

RGBM (RGBA8)

Same as RGBA8

Moderate USC cost for encoding / decoding the data

Hardware does not natively support filtering on this format

Encoding algorithm improves the range of values that can be represented by the RGB channels compared to standard RGBA8

No alpha sacrificed to provide improved RGB range

RGBdiv8

(RGBA8)

Same as RGBA8

Slightly more complex than RGBM to encode / decode the data

Hardware does not natively support filtering on this format

Encoding algorithm improves the range of values that can be represented by the RGB channels compared to standard RGBA8

No alpha sacrificed to provide improved RGB range