Is there any way to get the pixel counts of the segmented image using graphcut

I am using graphcut matlabs

Ncut = (graphcuts(bad3,3,50))

method to segment grayscale image. Is there any way to get the pixel counts? I am getting the segmented image as binary. How to convert the binary image to grayscale and get the pixel count of the segmented grayscale image

[Walter Roberson]

Is that https://www.mathworks.com/matlabcentral/fileexchange/40669-graph-cut-for-image-segmentation that you are using?

Answer 1

[Walter Roberson]

nnz(Ncut .* bad3)
nnz((~Ncut) .* bad3)

[andhavarapu lokesh]

sir what is this nnz

[andhavarapu lokesh]

>> nnz((~Ncut).* bad3); Error using .* Integers can only be combined with integers of the same class, or scalar doubles.

[Walter Roberson]

https://www.mathworks.com/help/matlab/ref/nnz.html

"n = nnz(X) returns the number of nonzero elements in matrix X."

I presumed here that when you asked for "pixel counts" of a grayscale matrix that you were interested in the number of non-zero grayscale pixels. If you just wanted to know how many entries were there regardless of whether they are 0 or not, then

nnz(Ncut)
nnz(~Ncut)

Another way of writing nnz(Ncut) would be

sum(Ncut(:))

since each entry in Ncut is binary (0 or 1), this counts the number of non-zero entries, which is the same thing nnz does except nnz would be expected to be faster.