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



On Tue, Sep 7, 2010 at 4:53 AM, Mark Callow <callow_mark@hicorp.co.jp> wrote:
> 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.

+1

PNG and JPG should not be treated differently.

> 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.

See other post for why I think two things are being conflated here.

-T
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