444 and RAW format

[Dan R]

Can some one please give me a fairly simple explanation between RAW and 444 formats, I have a basic understanding i just want to make sure im on the right lines, and what is better?

Cheers
Dan

 

[J. Eric Camp]

What's better doesn't really work. It's up to the application, end result and personal aesthetics.

 

[Uli Plank]

RAW in the case of RED is a very special kind of black-and-white image which you can't use without de-bayering to an RGB image (or YUV, if needed).
444 is normally RGB with full bit depth for all three channels. Sometimes it's used for YUV too, but normally YUV is reduced to 422, so the color channels are downsampled.

RAW has 12 bit per pixel, which can be preserved in 10 bit log, but not in 10 bit linear. 444 is 10 bit in many cases.

 

[Kenneth Elkington]

They are not contradictory terms.

RAW is the raw information from a bayer pattern sensor. Essentially this means that information from each photosite is recorded as simple numeric information, that is later assigned color information through the debayering process. This is done by identifying the color channel of each individual photosite and then recording the information as RGB or YUV.

4:4:4 is a term related to chroma sampling and subsampling, as opposed to other common sampling spaces such as 4:2:2 and 4:2:0. This can be better explained here, http://en.wikipedia.org/wiki/Chroma_subsampling.

 

[Hans von Sonntag]

RAW cannot be viewed. It must be decoded to a RGB/YUV file, usually 10 Bit. 444 refers to a RGB or YUV file in which no channel is horizontally down sampled. In YUV 422 the U and V channel are horizontally downsampled by two - a kind of compression if you like.


Hans

Edit: Too slow, what Uli and Kenneth said.

 

[Dan R]

Thanks Guys, I appreciate your answers

Cheers

Dan