"Reverse LUT" in UE PostProcessVolume for matching TV colors for virtual production

Development Cinematics & Media
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1

Hi there and thanks for reading!

I am testing a TV for a small virtual production setup and now wonder if it is possible to sort of reverse engineer the “inbuilt LUT” of a TV.

First I tried to find a TV that can be color calibrated by using appropriate hardware like CalMan. But a technician from Samsung assured, that there is no possibility to “inject” a LUT into a TV to calibrate it, this can only be done when using e.g. Micro LED displays or so.

Now taking this for granted I wonder if it is possible to sort of generate a “reverse LUT” that can be applied within UE. My idea is that this “reverse LUT” takes the character of the TV into account, pushes and pulls colors (within a PostProcessVolume?) in order to make the TV display a result that is as close as possible to the desired one.

Anyone having any advices for “reversing a LUT” or color grade a TV? Thanks a lot!

2

If your goal is to match the display on a TV to what you see on a monitor, you could use an ACES OpenColorIO (OCIO) config to do that. Unreal by default uses an ACES Output Transform for an sRGB display (adding in a gain of 1.45). You would just need to set the Output Transform to the standard for a TV which is Rec.709. Additionally you could add in that gain of 1.45 to the Rec709 Output Transform.