Jump to content
  • Advertisement
Sign in to follow this  
Prune

OpenGL Cost of sRGB vs 16-bit float

This topic is 3724 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

From http://opengl.org/registry/specs/EXT/texture_sRGB.txt
Quote:
8-bit components of sRGB texels are converted to linear RGB values which requires more than 8 bits to avoid lose of precision. This implies the filtering involve more than 8 bits of color precision per component.
So it seems that every time the texture is used, the value is de-gammaed into a 16 bit format. I'm wondering what kind of tradeoff this extra processing is in comparison to manually de-gammaing non-HDR textures and storing them in 16 bit (since putting de-gammaed sRGB into 8 bit linear loses some bits in low brightness parts of the dynamic range). Is extra processing likely to be higher or lower cost than the extra memory of a 16-bit per channel texture format?

Share this post


Link to post
Share on other sites
Advertisement
It's impossible to say, as it is completely implementation dependent and can vary widely from one 3D chipset to the next.

Just try both and profile to know how performance behaviour is on your GPU. Just keep in mind that it might be entirely the opposite on some other GPU. That said, it's very likely that you won't even notice any difference between both, unless you are seriously fragment limited. And even then, it's likely that the texture transfer bandwidth and cache behaviour is going to have a much higher impact on performance than some cheap gamma correction.

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!