Design issues (opengl, hdr, channels, pigment(?))

[Boudewijn Rempt]

On Friday 02 February 2007, Tom Burdick wrote:
> Out of curiousity, when does opengl produce incorrect results?
>
> If your using the built in image filtering then perhaps. If your using
> shaders or lookup tables (textures full of look up values) there shouldn't
> be a problem.

Well, graphics cards don't provide the same precision that the cpu does, so 
the results of computations can come out differently: 
http://www.gpgpu.org/wiki/FAQ#Where_can_I_get_information_about_GPU_floating_point_precision.3F_Is_it_IEEE-compliant.3F.

And if I ever get down to implementing a fast projection mode by putting all 
layers in u18 rgba textures & blending them using opengl, you can bet the 
results will be different from what we get when we carefully blend u16 lab 
layers on the cpu:-).

-- 
Boudewijn Rempt 
http://www.valdyas.org/fading/index.cgi
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