ColorManagement: Dithering Improvement
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Authored by Clément Foucault (fclem) on Feb 14 2020, 4:23 PM.

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Sergey Sharybin (sergey)
Brecht Van Lommel (brecht)

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rB852cdd476b55: ColorManagement: Dithering Improvement

Summary

Unlock property range.
Use triangular noise to reduce overall noise. Remap range to preserve perceptual intensity.
Center noise distribution around 0 for GPU implementation because of rounding.
Do dithering after merging overlays.

Effect of using triangular noise is not really noticeable if you don't use
really low bitdepth. But doing a test in the shader were we artificially
reduce the bitdepth (col = (col * 16) / 16;) reveals the real difference.

Diff Detail

Repository: rB Blender

Event Timeline

Clément Foucault (fclem) created this revision.Feb 14 2020, 4:23 PM

Harbormaster completed remote builds in B6624: Diff 21726.Feb 14 2020, 4:23 PM

The implementation looks fine. Please add some comments in the code to explain where these algorithms come from, at least mention the name "triangular noise".

I do wonder a bit if it's worth the (probably small) performance impact if you need to make an artificial test case to see advantages. But you can judge that better than me.

This revision is now accepted and ready to land.Feb 14 2020, 5:33 PM

Clément Foucault (fclem) mentioned this in T73834: Rendering a scene without light: result is not completely black.Feb 15 2020, 8:51 PM

Closed by commit rB852cdd476b55: ColorManagement: Dithering Improvement (authored by Clément Foucault (fclem)). · Explain WhyFeb 17 2020, 3:47 PM

This revision was automatically updated to reflect the committed changes.

Clément Foucault (fclem) added a commit: rB852cdd476b55: ColorManagement: Dithering Improvement.