# How to count number of red, blue and green pixels in image.

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k khaja on 8 Oct 2022
Commented: Walter Roberson on 8 Oct 2022
Hi,
I woud like to know, how can I count number of red, blue and green pixels in image.
Walter Roberson on 8 Oct 2022
If RGB components are integers 0 to 255, then is [1 0 0] red? That is, the smallest change towards red away from black: does that count as red, or does it count as black? It has red component but not green or blue... under some definitions that would have to count as red.
rng(12345);
Z = zeros(48, 64, 3, 'uint8');
r = randi(size(Z,1),1,1);
c = randi(size(Z,2),1,1);
Z(r, c, 1) = 1;
image(Z)
title('which is the Red pixel?')
fprintf('Red pixel is at x = %d y = %d\n', c, r);
Red pixel is at x = 21 y = 45
Personally I cannot detect the red pixel until you get up to around 40 instead of 1

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