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I'm a bit confused regarding color in bits.

I know of two color "types": Many more expansive displays offer 10-bit panels with 1 billion, instead of 16 million different colors.

Better video cameras use 10-bit 4:2:2 subsampling to save storage space by only giving 4 color values, for 8 pixels.

Are those two different types of color-types? Or how does one translate to the other?

Thanks!

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The bit depth and the sub-sampling method are related but different parameters of the imaging system. As you noted, the bit depth determines how many different colors the system can display. The more colors that can be imaged, the closer to reality the image looks. You also get fewer quantizing artifacts.

The sub-sampling method is a form of compression. Human vision is less sensitive to colors than it is to luminance, or black/gray/white, information. By only sampling some pixels for color, the system saves data by trading off some resolution.

(You should note that the "better film cameras" you reference in your question probably use 4:4:4 sub-sampling and better/professional video equipment use 4:2:2.)

You can have any combination of bit depth and sub-sampling. So a system can be, among other possible configurations:

  • 8-bit 4:2:2
  • 8-bit 4:4:4
  • 10-bit 4:2:2
  • 10-bit 4:4:4
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  • I interpret the question to be: What's the difference between 10-bit cameras which designate 422 subsampling vs 10-bit displays which do not specify a subsampling method. As such, I feel like a complete answer should address the display side of the signal chain. I couldn't actually find much information on this, but I think that displays don't care if you send them 420, 422, or 444. I think that the display upsamples whatever chroma you give it, and never downsamples what you give it, so id doesn't make sense for display manufacturers to even mention it. I'm totally guessing, though.
    – Jason Conrad
    Dec 2, 2018 at 4:02
  • Thank you very much! I allways just saw 10bit 4:2:2 so I thought it must be 10bit to display 4:2:2 and 12bit for 4:4:4 :) With the display I can avtually answer myself, displays mostly do not subsample and display 4:4:4 color, and everything below. But there are (mostly) TVs, which do not accept 4:4:4 to achieve higher Framerates. Most games for example also don't outpur full color
    – Tim
    Dec 2, 2018 at 8:21
  • I think what I mean is that the TV isn't just going to not display color on half of its pixels, so it's going to spread chroma info to neighboring subpixels wherever it needs to, depending on the kind of signal it's receiving. That's what I mean by upsampling.
    – Jason Conrad
    Dec 2, 2018 at 9:08
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    To use a more accurate term, the display or a processor before the display will decode a 4:2:2 (or even 4:4:4) signal back to the native format that the pixel array requires. There are other steps, like converting the color difference signals back to RGB, too.
    – Michael Liebman
    Dec 2, 2018 at 20:17

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