Question

Write the function compute_histogram, in Matlab, that takes a grayscale image as input and returns a length 256 vector h which is the normalized histogram of the values in the image. h should have values from 0 to 1 and its components should sum to 1.

Answer 1

function [h]=compute_histogram(img)
[n,m] = size(img);
h = zeros(562);
for i =1:n
for j =1:m
h(img(i,j)) = h(img(i,j))+1;
end
end
% normalize
total_pixel=n*m;
h=h./total_pixel;

end

main.m

img = imread('pandu562.png');
figure(1);
imshow(img);
h = compute_histogram(img);
figure(2);
bar(h,1,'b');

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