count how many pixel has value 255 in an image

The image cameraman, how can we find how many pixel has value of 255? Please help me

Answer 1

[KALYAN ACHARJYA]

data=GrayImage==255;
total_pix=sum(data(:))

[Tu Nguyen]

So, we change the image to gray and apply that function. Is it correct?

[AndresVar]

Tu, cameraman is already gray. I will write here another way to write it.

GrayImage = imread('cameraman.tif');
count = sum(GrayImage==255,'all');
% yet another way
% count = nnz(GraImage==255);

btw you will see the maximum value of cameraman is only 253 so the count is 0.

you can also peep counts from a histogram

histogram(GrayImage)

[Tu Nguyen]

Thank you, I just use the cameraman as an example. Thank a lot

[KALYAN ACHARJYA]

@AndresVar Yes, Thanks for adding more.