3 ms·
When you're using a ringing filter, sRGB is often a better colorspace for upscaling than linear RGB, because it distorts the ringing artifacts to make them less
by mrob 5y ago
When you're using a ringing filter, sRGB is often a better colorspace for upscaling than linear RGB, because it distorts the ringing artifacts to make them less noticeable by putting them mostly in the highlights, not the shadows. It's not mathematically "correct", but it's better suited to human perception, similar to how minimum phase filters can perceptually outperform linear phase in audio processing, where pre-ringing is more noticeable than post-ringing.
See "Catch #3" here:
https://entropymine.com/imageworsener/gamma/ https://entropymine.com/imageworsener/gamma/
And you can sometimes get even better results using a sigmoidized colorspace. See:
https://legacy.imagemagick.org/Usage/filter/nicolas/#detailed https://legacy.imagemagick.org/Usage/filter/nicolas/#detaile...
- planede 5y agoIt still feels like that sRGB is accidentally better here, but a different, non-linear colorspace could outperform it for this case.
- rnvannatta 5y agoWell, sRGB is sort of perceptually linear. Its roots trace back to a 50s technology compromise between perceptual linearity, color gamut, & encoding cost for CRTs that held up with only minor tweaks until CRTs stopped being widely used. Maybe a fancier model like oklab would outperform it for this specific case, but only in quality, not performance oklab is more expensive to convert to/from compared to sRGB, which is usually free as your backbuffer and textures are usually sRGB.