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



On 07/09/2010 02:23, Gregg Tavares (wrk) wrote:

...

WebGL already specifies that if the incoming format is a lossless 8bit format (ie, an 8bit png) that the bits in the file must be passed straight through, no conversion. There are conformance tests for this. This is to support getting non-image data into WebGL.
Why should losslessly compressed files be treated differently than lossy compressed files? Just because they are more likely to be used for non-image data does not seem like sufficient reason. There are a lot of PNG images out on the web. People creating PNG files for, e.g. normal maps, can easily write a gAMA chunk indicating the gamma value is 1.0.

The only question that came up should there be an **option** to let the browser do color space conversion (and should that conversion be explicit). The simplest form of that is "should the browser be allowed to do whatever it normally does for img tags".
And the responses were (a) that doing "whatever it normally does for img tags" will provide data that will cause mathematically incorrect results in GL computations, even for image data, and (b) since browsers apparently care about correct color, descriptions of what is necessary to get mathematically correct results and correct color.

Regards

-Mark




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