Asked by M@lik Ali
on 1 Feb 2013

Hi ALL,

I want to calculate the means luminance value of an image block

i found the formula is..

luminance= 0.3 R + 0.59 G + 0.11 B

but how i can calculate the R, G and B values.

i know that

R=rgb_img(:,:,1) G=rgb_img(:,:,2) B=rgb_img(:,:,3)

but it give in the shape of matrix, i think i need only a single value of R,G and B, to use above luminance formula.

please help me out.

Thanks in Advance

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Answer by Walter Roberson
on 1 Feb 2013

Accepted answer

mean2(rgb2gray(rgb_img))

provided you have the toolbox installed.

Otherwise, calculate a luminance *array* using the R, G, B arrays, and then mean2() the luminance array.

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