Maybe this code can help you:

[m n] = size (database);

E = zeros (m,n);

for i = 1:m

for j = 1:n

E(i,j) = entropy(database(i,j));

end

end

These steps are for measuring Entropy.I want to know about maximum entropy after measuring using matlab,thank you.

Do you mean you want to find out the maximum value among all the entropy values? If so, you can try the following code after Mohammad's code:

max(max(E));

Yes true exactly what I mean I have tried this also but I get erroneous output like if 7.885,7.2,7.7225 I get 7.225 as maximum value while 7.885 is the maximum.i also wrote explicit code for finding maximum I assigned all entropy values to array then tried to find max using both max() as well as code for max value in array inside loop but both gives same result.

That's weird... It supposes that 'max(max(E))' will output 7.885 if E=[7.885,7.2,7.7225].

Could you attach your code for calculating the maximum?

E=entropy(I);

en=[num2str(E),'Entropy\t',num2str(k)];

disp(en);

me=max(max(E));

disp(p);

s=['Maximum entropy:',num2str(me)];

disp(s);

these statements are inside for loop block for all images in folder where I refers to each image in folder.

If 'I' is an image, then 'E' is the entropy of this image 'I'. 'E' is a value. So the maximum of 'E' is 'E' itself.

I think you should store all the entropy value for each image in a vector 'E'. The code inside the loop should be:

for n = 1:num_of_images

E(n) = entropy(I_n);

end

max(max(E));

The loop to calculate entropy for each image should be like Mohammad's code above. He construct a matrix E to store the entropy value (but for your code, E is a constant). After that, using max(max(E)) will be ok.

Thank you Yu Zhang my problem solved.

Salam,thank you Mohammad Abdullatif my problem solved!