Eliminating(excluding) the while or black color in a color histogram function matlab

I have this implementation of a function that performs color histogram on an image. and i would like to exclude and eliminate a particular image. is there a way to do it?

for example i want my function to totally forget about the white color.

I do really appreciate your help

Here's the function code:

function H = colorhist(I, nBins)
%%RGBHIST: color Histogram of an RGB image.
%
% nBins   : number of bins per EACH color => histogram is 'nBins^3' long.
% H       : The vectorized histogram.
%

if (size(I, 3) ~= 3)
    error('rgbhist:numberOfSamples', 'Input image must be RGB.')
end

H=zeros([nBins nBins nBins]);
for i=1:size(I,1)
    for j=1:size(I,2)
        p=double(reshape(I(i,j,:),[1 3]));
        p=floor(p/(256/nBins))+1;
        H(p(1),p(2),p(3))=H(p(1),p(2),p(3))+1;
    end
end

H=H(:);
% Un-Normalized histogram
    H=H./sum(H);
     %l1 normalization
end

Answer 1

[Image Analyst]

How are you defining "white"? Let's say it's everything brighter than 240 in all 3 components. Then you should be able to do:

H(240:end, 240:end, 240:end) = 0;

[alladin]

Thank you very much