PIXEL counting at grey scaled picture

I have a picture which is greyscaled and i want to count the number of pixels from 200-255( the bright ones) from the histogram.Any ideas about the coding or other way? Thank you!

Answer 1

[KALYAN ACHARJYA]

%Using Histogram (Considering 256 Levels)
[counts,binLocations]=imhist(grayImage);
pix_counts=sum(counts(200:end))

##

%% 2nd Method, easier 
high_pix=grayImage>199;
pix_counts=sum(high_pix(:))

[DIMITRIOS ZAFEIRIOU]

Thank you very much Mr.Kalyan Acharjya!

Answer 2

[Image Analyst]

And yet another option:

brightRegions = grayImage >= 200;
numBrightPixels = nnz(brightRegions);