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Re: [Public WebGL] Gamma correction and texImage2D/texSubImage2D




On Sep 6, 2010, at 7:31 PM, Mark Callow wrote:

On 06/09/2010 21:34, Chris Marrin wrote:

But we need to make an assumption if the incoming PNG image omits any color space information. I think it is out of scope to add the ability to let the author choose the color space for these images as they are read in with texImage2D. So do we choose sRGB or linear?
Why is it out of scope? Not doing so violates the PNG spec. I think it is entirely reasonable to provide a way for the application to give WebGL information about the gamma of the samples in the PNG file. Allowing specification of physically linear vs. non-linear covers 98% of use cases.
Then that's an HTML or browser specific problem. It's just like providing information about an image, such as whether or not it contains an alpha channel. These are nice features and maybe we can do them in a future release. But it would be a mistake to widen the scope of this discussion to include such functionality.

This discussion started out focusing on a flag to turn off any image processing happening to incoming images, so we can get pure pixel values, typically so a texture can be used for purposes other than image data. That discussion exposed the fact that we have not defined the color space of our canvas. So I believe we need to deal with those two issues and no others.

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~Chris