[PlayRaw] Sunset on ferry

[age]

@flannelhead

Is your tone-mapping followed by some hue-preserving gamut-mapping (or chroma clipping) operation (in a perceptual colorspace)? Pardon my ignorance here, I’m not very familiar with Photoflow.

No, I just let rgb channels hard clipping

@flannelhead

I’m curious about the way you handle chroma here - you seem to use the difference between the norm and individual channels as the representation of chromaticity. Is there a particular reason you chose to do this rather than just multiply the original RGB ratios (i.e. (r / norm, g / norm, b / norm) by the tonemapped norm? I.e. final RGB (color preserving) = tonemapped norm / original norm * (r, g, b). This is the way it’s done in filmic. If I understand correctly, your approach is to rather adjust the amount of white in the pixel.

Yes, sadly when used with a sigmoid shaped tonemapper shadows looks too much desaturated and highlights have too much or too low saturation.

My approach is simply copy the hue channel from the image before tonemapping to the rgb per channel tonemapped image

@flannelhead

Are there any research papers / other resources you’ve found useful or followed in developing the tone-mapping operation?

I don’t think, however the film-like curves used in Rawtherappe (developed by Adobe) are just the equivalent of blending the hue from the HSV color space to the rgb tonemapped image

@flannelhead

Have you experimented with tone-mapping (or just the hue preservation) in perceptual color spaces such as Oklab?

Yes
https://discuss.pixls.us/t/oklab-cielab-linear-cielab-tonemapping/28767

The main issue with this method is that it removes way too much saturation from red,orange,yellows hues

However copying only the hue from oklab to the rgb tonemapped image it would be better , I haven’t test it, yet