Chroma 4:4:4?

[Techicolors]

i heard it being thrown around when considering a large TV for desktop use, but i have no idea what it means. 

[Electronics Wizardy]

It means that that resolution of the luma is the same as the chroma. Most video is 4:2:0, which means that the chroma(color data) is half the resolution of the black and white data.

 

Most of the time in video you have a black and white level, then a seprate channel for the difference between black and white and 2 of the colors.

[Samfisher]

http://blogs.adobe.com/VideoRoad/2010/06/color_subsampling_or_what_is_4.html

[Randomguy1911]

http://www.red.com/learn/red-101/video-chroma-subsampling

 

This site has some good comparsions.

[Glenwing]

8 minutes ago, Technicolors said:

i heard it being thrown around when considering a large TV for desktop use, but i have no idea what it means. 

Chroma subsampling removes data from the image (lowering the image quality) to reduce bandwidth.

 

RGB doesn't use subsampling, so when people say "RGB 4:4:4" it is redundant. RGB is always "4:4:4-equivalent" as that term doesn't even apply to RGB

YC_BC_R 4:4:4 is equivalent in data to RGB

YC_BC_R 4:2:2 uses 2/3 as much data as 4:4:4 (so instead of 60 Hz you could get 90 Hz, with reduced image quality)

YC_BC_R 4:2:0 uses 1/2 as much data as 4:4:4 (so instead of 60 Hz you could get 120 Hz, with further reduced image quality).

 

TV and movies are both encoded in YC_BC_R 4:2:0 to reduce bandwidth needed for transmission over cable, or reduce file size on a disc. So if you're getting a TV for TV/movie watching, it's not necessary to have 4:4:4 capability (but people obsess over it because "omg better image qualityyyy"). For computer usage, which encodes signals in RGB, it's preferable to have a TV that supports 4:4:4 or RGB. All monitors support RGB.

[Techicolors]

thank you for the answers

 

7 minutes ago, Glenwing said:

Chroma subsampling removes data from the image (lowering the image quality) to reduce bandwidth.

 

RGB doesn't use subsampling, so when people say "RGB 4:4:4" it is redundant. RGB is always "4:4:4-equivalent" as that term doesn't even apply to RGB

YC_BC_R 4:4:4 is equivalent in data to RGB

YC_BC_R 4:2:2 uses 2/3 as much data as 4:4:4 (so instead of 60 Hz you could get 90 Hz, with reduced image quality)

YC_BC_R 4:2:0 uses 1/2 as much data as 4:4:4 (so instead of 60 Hz you could get 120 Hz, with further reduced image quality).

 

TV and movies are both encoded in YC_BC_R 4:2:0 to reduce bandwidth needed for transmission over cable, or reduce file size on a disc. So if you're getting a TV for TV/movie watching, it's not necessary to have 4:4:4 capability (but people obsess over it because "omg better image qualityyyy"). For computer usage, which encodes signals in RGB, it's preferable to have a TV that supports 4:4:4 or RGB. All monitors support RGB.

so what'll happen if i hook my PC to a TV that doesn't support 4:4:4? the image will look "blurrier"? 

 

and can you change the chroma subsampling on a TV? 

[Glenwing]

4 minutes ago, Technicolors said:

thank you for the answers

 

so what'll happen if i hook my PC to a TV that doesn't support 4:4:4? the image will look "blurrier"? 

 

and can you change the chroma subsampling on a TV? 

Text will be difficult to read if the TV doesn't support 4:4:4.

 

You would change it from the computer, which negotiates the signal and image mode with the display. If you have an NVIDIA graphics card that can be done from the NVIDIA control panel.