How to use built-in entropy function

Hi,

i would like to calculate entropy of an image using entropy function. when use this function like this

E = entropy(uint8(output_image)

i can see a value. But when i remove uint8, i see 0 as a result. type of output_image is double. Also when i try to calculate entropy like described in this link

E =  -sum(histogram_of_output_image.*log2(histogram_of_output_image));

i see NAN (not a number) as a result

[Image Analyst]

Make sure there are no zeros in your image.

[Mustafa Uysal]

But it can be zero in any image. Why it is a problem?

Answer 1

[Subhadeep Koley]

Hi, Can you attach your "output_image" ? So that we can reproduce the issue.

Otherwise you can try the code below.

E = entropy(uint8(rescale(output_image, 0, 255)))

[Mustafa Uysal]

I tried and it worked