MATLAB Answers


Does (:,:,1) code work to calculate Y component in YcbCr color model?

Asked by satish thapaliya on 20 May 2013

i am currently studying color models in matlab specially YCbCr color model. I had an RGB image. First i converted image into YCbCr by using code rgb2ycbcr. then i used (:,:,1) to see the luma component of the image. is the value i am seeing the actual value of image luma? Anyone out there to comment on it?



1 Answer

Answer by Image Analyst
on 20 May 2013
 Accepted answer

Almost. Y is the luminance. Y' is the luma. See wikipedia:

Actually for an RGB or gray level image, the light collected actually has units of lumen*seconds. But that's only if you're interested in what the physical units would actually have. I can explain it further (like I've done here before) if you're interested. It often doesn't matter when doing image analysis and you can often find stuff just fine without knowing the actual real world units.

  1 Comment

Image Analyst, Suppose we are studying the Red-shift of the light based on RGB samples ("photometry") can we only focus on the R block? eventually Y' in ycbcr space?

Join the 15-year community celebration.

Play games and win prizes!

Learn more
Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

MATLAB Academy

New to MATLAB?

Learn MATLAB today!