Write the function plot_histogram that takes as input a histogram (as returned from compute_histogram) and plots it similar to the plots shown below. The x-axis should range from 0 to 255 and be labeled intensity value. The y-axis should range from 0 to the maximum value of the histogram and should be labeled PMF (for probability mass function).

The function of compute_histogram 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.

function h = computehistorgram (img)

[m,n] = size(img);

h = zeros(1,256);

for i = 1:m for j = 1:n h(img(i,j)+1) = h(img(i,j) + 1) + 1; end end

total = m*n; h = h/total; end