Gamma-Aware Workflow questions

A crude example: if you're loading a JPEG, it's assumed to be nonlinear. If you're loading an OpenEXR or a PFM, these are assumed to be linear. If a file has an explicitly specified gamma, we should respect that, but I don't know if this has been implemented. I think we'll get back to gamma in later betas -- I'd like to have a stab at a proper linear workflow.

Also, you can expect all the facts you're asking about to be listed in the help article in the final product.

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Vladimir Golovin wrote: Well, a proper linear workflow would keep everything linear and just gamma-correct for display purposes.

Here's how I see it (taken from http://www.filterforge.com/download/beta2/gamma.html):

1. Any non-linear input images, such as JPEG photos, are linearized, i.e. converted to linear gamma, on loading. Color picker colors are linearized as well before getting passed to components or renderer. HDR images such as OpenEXR are assumed to be linear, so they should be loaded without linearization unless they explicitly specify a non-linear gamma (in general, Filter Forge should respect the gamma value specified in image files, but it remains unclear whether it is possible to handle gamma correctly when Filter Forge is called as a plugin from a host application). Note that any "data" textures and colors such as normal maps and height values should be left "as is" – they shouldn't be linearized.

2. All internal calculations are performed in linear color space. It so happens that we already do everything in linear, with the exception of lighting, which assumes its diffuse map to be non-linear and linearizes it, adds the light, then gamma-corrects the result back to monitor gamma.

3. The output image and any previews are corrected back to monitor gamma, unless the output image is an HDR image or a "data" texture such as a specular, bump or normal map.

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Crapadilla wrote: Of course, color pickers would have to be gamma-corrected as well...

Yes, the color pickers (and color swatches as well) are one of the remaining gaps in my understanding of a proper linear workflow.