These images are the result of filtering with a Hurlbert regularization filter, then biasing to gray. A relaxation was then applied, taking into account edges in luminance to constrain the color diffusion within regions belonging to a single surface.
| Gamut | Illuminant A | Illuminant B | Illuminant C |
|---|---|---|---|
| All |  |
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| Little Blue |
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| Little Red |
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Jump to view an intermediate step, after the application of the regularization filter, and the spectral normalization, but before chroma relaxation.
A Blackman window was used to avoid ringing from the effects of a finite filter length. The frequency response of the actual filter used was:
