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rafael3d

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    Discovery: 4K 8bit 4:2:0 on the Panasonic GH4 converts to 1080p 10bit 4:4:4

    In: Cameras

    Posted

    The compression algorithm it's not important here. I did some synthetic tests (>post #118) simulating a best case scenario (a full 4K 4:4:4 8-bit image to a 2K 4:4:4 32-bit). I've tried different scaling algorithms and even adding noise doesn't give us any extra colour information. 

     
    We technically get an image with increased bit depth(since we're blending some pixels), but it doesn't translate in smoother tonality or better colours.

     

     

    I'm sure when the gh4 starts hitting stores there will be people showing that it is possible to pull out 444 and somewhere between 8-10 bit in a image downconverted to 1080p from 4K 420 8bit. The exact performance will depend on the algorithms that panasonic utilized.

    Discovery: 4K 8bit 4:2:0 on the Panasonic GH4 converts to 1080p 10bit 4:4:4

    In: Cameras

    Posted

    I did some tests on Nuke (compositing software), and couldn't see much improvement downscaling a 4K 4:4:4 8-bit image to a 2K 4:4:4 32-bit (Nuke operates exclusive at the floating point colour depth).
     
    I created a large, gentle ramp and saved as an 8-bit image. The image was reloaded and downscaled to 50%. The differences are a few more pixels were the banding transition occurs. Adding some noise (error diffusion) doesn't alleviate the problem too. We have an image with more information, but it doesn't translate in smoother tonality or better colours.
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