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Author Topic: YCbCr color space and RGB  (Read 2804 times)

mbalensiefer

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YCbCr color space and RGB
« on: June 29, 2012, 11:07:55 AM »

I have TIFFs in the YCbCr color space.
Apparently, Y′CbCr is not an absolute color space; rather it is a way of encoding RGB information.
These will be displayed on an RGB monitor. Will converting these images to RGB lose any color information?
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Sareesh Sudhakaran

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Re: YCbCr color space and RGB
« Reply #1 on: June 29, 2012, 12:00:55 PM »

Your TIFF is already an RGB image. It might be a still from a video that is chroma sampled.

Y'CbCr has no place in the TIFF specification. Y'CbCr is the currency of video land - in TIFF land they don't speak that language. RGB is a color model. Y'CbCr is a chroma sampling and video encoding specification (compression for video) that is a digital byproduct of other similar analog specs, like YPbPr, etc.

Neither of them are color spaces.

If your TIFF came from a video shot on an HD camera, it is probably in the Rec. 709/sRGB color space (same thing, almost). If it came from a PAL SD camera, it is in the PAL color space. If it came from an NTSC SD camera, it is in the NTSC color space. If it came from a RAW camera (like the Alexa, F65 or Red), then it might have its own proprietary color space (like Red or the F65) or maybe it's like a still camera RAW file (ArriRAW) which doesn't have a color space yet. Also, higher-end video cameras have LUTs, special-gammas and S-Logs that make things complicated.

To answer your question: The file won't lose information - but you might have already lost information in your TIFF conversion. Need more specific information for a better answer.


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chrismurphy

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Re: YCbCr color space and RGB
« Reply #2 on: July 12, 2012, 11:00:10 PM »

It's a good answer!
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deejjjaaaa

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Re: YCbCr color space and RGB
« Reply #3 on: July 12, 2012, 11:16:08 PM »

Y'CbCr has no place in the TIFF specification.

http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf

it has a place there as TIFF extension, as well as CMYK, LAB, etc
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Sareesh Sudhakaran

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Re: YCbCr color space and RGB
« Reply #4 on: July 14, 2012, 11:26:09 AM »

You are correct. Thanks for pointing it out.
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