OpenEXR images with linear and non-linear gamma look the same

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zazik
Posts: 2
Joined: Mon Oct 24, 2022 5:41 am

OpenEXR images with linear and non-linear gamma look the same

Post by zazik »

Hello,
I have two FP16 .exr images with exact same data but one with linear gamma flag and the other one without.

Linear flag is shown in Image->Properties->ExifTool->OpenEXR as
"Channels: B half linear 1 1, G half linear 1 1, R half linear 1 1".

And the one without it
"Channels: B half 1 1, G half 1 1, R half 1 1".

They both look the same in XnViewMP, and, intuitively, I think they shouldn't.
I guess, Format setting->Read->OpenEXR->Gamma is used for both images but it should only be used for non-linear ones.

Is there any way to remediate this by taking into account linear flag set in the file?

Thank you.
Last edited by zazik on Tue Nov 22, 2022 4:51 pm, edited 1 time in total.
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xnview
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Re: OpenEXR images with linear and non-linear gamma look the same

Post by xnview »

could you send me the 2 sample files? Currently there is no way
Pierre.
zazik
Posts: 2
Joined: Mon Oct 24, 2022 5:41 am

Re: OpenEXR images with linear and non-linear gamma look the same

Post by zazik »

Sure thing, attached.
Also, EXR (AFAIK) only supports 32-bit integer format, but ExifTool reports it as "int8u" and XnView produces black picture, UINT samples attached too.
Thank you.
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