Photoshop, 32-BPC and exporting .exr

marks

So, according to the docs I've read - anything exported from photoshop in 32-bit per channel mode should be exported as linear.

This seems correct, the .exr I'm exporting does have metadata saying its saved in linear. However, it looks like Photoshop is saving sRGB data into the texture, but tagging it as gamma 1.0 instead of gamma 2.2

Has anyone encountered this before? I have example images if anyone needs. I've been doing validation of the EXR textures using the ILM reference implementation viewer.

chronic

As far as I know exr files are always gamma 1.0 and need to be opened/interpreted in different color spaces in a host application.
Perhaps you have a slight misunderstanding about saving an 8-bit file into a different bit depth? The color values are directly transferred without 'interpretation'. Your file data doesn't care about sRGB, linear tagging, its just numbers.

Kon

You operating system attaches a color space to the image, if you choose in Photoshop not to do it. Anyways, this doesn't change if the image is linear or not.
It's not Important for being linear what color space is being used. You can have Adobe RGB in Linear, sRGB in Lineae and so on...
I hope I could help you

marks

For future googlers - the issue I was experiencing was when converting a document from 8/16bpc to 32bpc Photoshop changes the document ICC profile to a linear-gamma profile, which is totally fine except it uses an approach which preserves the visual look of the image, rather than preserving the RGB values. So Photoshop was changing the RGB values in my image when I converted the document to 32-bpc.
My fix was to create a Linear ICC profile (by taking the default sRGB profile and lowering it to gamma 1.0), and then using Edit->Assign Profile, assign this Linear gamma ICC profile to the document before converting to 32-bpc. This prevents Photoshop doing any funky gamma conversion and you get correct linear data exported to the EXR.