how to suppress max value of b component

For fire detection algorithm for class A flames I need to apply rules on the red R, green G, and blue B component on each pixel of the frame acquired, but before that I need to suppress the maximum values (255) of the blue component image so that the flame will not be captured as a source of bright light.

Answer 1

[TADA]

You can find those pixels you want to ignore first then analyze the rest

ignoreBrightnessFactor = 255;
mask = B < ignoreBrightnessFactor;
% do calculations on relevant pixels
doSomething(R(mask), G(mask), B(mask));

[Sarmad Paracha]

so how can i apply this now on the orignal image which should show image with suppressed b channel.

[TADA]

If you want to simply change the blue value of those pixels you can do

%use the factor variable from above
B(B >= ignoreBrightnessFactor) = 0;

Or if you want to remove them altogether:

 %use the mask vector from above
R1 = R(mask);
B1 = B(mask);
G1 = G(mask);

Answer 2

[Walter Roberson]

B(B==255)=0;

[Sarmad Paracha]

so how can i apply this now on the orignal image which should show image with suppressed b channel.

[Walter Roberson]

YourImage(:, :, YourImage(:,:,3) == 255) = 0;