MATLAB: How to calculate the pixels occured by white color in binary image

Question

After converting the image to binary image and my primary aim is count the area covered by the white color and the black color in the binary image. For Example, we have performed edge detection on the image and we got an output image in binary image. I want to calculate the area of the edge in the image which are in white.

Answer 1

To find the white and black pixels:

numWhitePixels = sum(binaryImage(:));
numBlackPixels = sum(~binaryImage(:));

To get the number of perimeter pixels of the white regions

perimImage = bwperim(binaryImage);
numPerimeterPixels = sum(perimImage(:));

An alternate way to get the area of the white is to use bwarea():

% A weighted sum of white pixels that depends on shape of perimeter.
area = bwarea(binaryImage);