Matlab code to generate images from entropy

Question

Could you please help me with this question:

Assume that on average in binary images, 75% of the pixels are white, and 25% are black. What is the entropy of this source? Model this source in Matlab and generate some sample images according to this process

Answer 1

To find the entropy, you just need to apply the definition:

H = -0.25 * log2(0.25) - 0.75 * log2(0.75)

Since we are using log2, the result will be in bits.

As for generating a Matlab B&W (i.e. binary) image of size 512x512, you can simply do:

im = rand(512) < 0.75;

By convention, true = 1 = white and false = 0 = black.