The proper lighting will help you to get an evenly lit background which then will make pulling off the perfect chroma key a piece of cake. If you can live with a 5% loss, it might be 15-20% better than 4:2:2 of same resolution, but all of this is a rough estimate and your mileage may vary.It goes without saying that the perfect chroma keying starts with a seamless green screen setup. This is why you don't hear about people using it, its just not practical. This is because Prores and Cineform aren't truly lossless and you would need a 100% uncompressed video codec with ridiculously large file sizes like 16 bit TIFF/PNG/EXR.

and if the dither algorithm isn't perfect, you won't gain any advantage because normally, a 4:2:0 4k image will key better than a 4:2:2 image due the 4x more luma per chroma information.Īs to getting the same power of 444 in a downscaled image, in a perfect world, you might only lose 5% information.

Prores and Cineform have a 444 RGB codec but your file sizes will be massive, perhaps even bigger than the original you are trying to save space with. Note: this won't fix banding in skies because it is a local domain transform only and is not aware of group pixel issues. The luma will scale from 8 to 10 bit and the chroma from 4:2:0 to 4:4:4. From what I undestand, you'd need to convert your YUV video to 444 RGB, in 16 or 32 bpc environment, do a bicubic downscale to HD with full RGB dithering and capture in a 444 RGB video codec.

Chroma keying in premiere pro