How to randomly select n number of pixels from an image whose value is one and change those pixels value to zero?

How to randomly select n number of pixels from an image whose value is one and change those pixels value to zero?

Answer 1

[Thorsten]

 ind = find(I == 1);
 r = randperm(numel(ind));
 r = r(1:n);

 I(ind) = 0;

[Anushka]

thank you sir it worked.

[Anushka]

Sir what does the line r = r(1:n); does.