calculate the percentage of B&W image

I have a black and white image, how do I calculate the percentage of the white area over the black area?

Answer 1

[Guillaume]

percentageWhite = nnz(yourimage) / numel(yourimage);

nnz gives you the number of white pixels, numel the total number of pixels.

And note:

percentageBlack = nnz(~yourimage) / numel(yourimage);

Answer 2

[Nithin Banka]

If 'BW' is your binary threshold image,

pix = size(BW);
no_of_pix = pix(1)*pix(2);
no_of_white_pix = sum(sum(BW==1));
percent_of_white_pix = no_of_white_pix*100/no_of_pix; %This gives the percentage of white in the image.