Image processing class with MATLAB code

Write a MATLAB program for computing the histogram of an image using for loops! Your function title should be: function [n] = MyHistogram( I ) I is the input gray-level image, n is the histogram of I. Then test your function using the image phoenix-lander.tif

Also please give me a plot of histogram MyHistogram( I ) of original image,

Explain why the resulting image was enhanced as it was.

Thank you for your help in advance.