How to calculate no. of pixels having value greater than a particular RGB value?
15 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
I want to calculate the no. of pixels having value greater than a particular RGB value for eg. lets say 180. (pic(mm,nn,1) > 180 && pic(mm,nn,2) > 180 && pic(mm,nn,3) > 180).
0 Kommentare
Antworten (3)
Azzi Abdelmalek
am 6 Nov. 2013
Bearbeitet: Azzi Abdelmalek
am 6 Nov. 2013
idx=pic>180
out=sum(idx(:))
0 Kommentare
Image Analyst
am 6 Nov. 2013
% Extract the individual red, green, and blue color channels and threshold them.
binaryR = rgbImage(:, :, 1) > 180;
binaryG = rgbImage(:, :, 2) > 180;
binaryB = rgbImage(:, :, 3) > 180;
% AND the binary images together to find out where ALL THREE are > 180.
binaryImage = binaryR & binaryG & binaryB;
% Count the number of pixels where it's true that all 3 are > 180;
pixelCount = sum(binaryImage(:));
4 Kommentare
Anbarasan Rajan
am 8 Nov. 2018
pixelCount=sum(binaryImage(:)); i think this will only give us the total pixel intensity. for example, if 10 pixels are having the intensity of 50, this comment will give us 500 which is the total intensity value of the pixels present in thet image.
if i'm wrong please let me know.
Guillaume
am 8 Nov. 2018
"if i'm wrong please let me know."
You're wrong. binaryImage is 1 when all 3 channels of the pixel is above the threshold, and 0 otherwise. Hence the sum is the number of pixels, Image Analyst could have used nnz instead:
pixelCount = nnz(binaryImage);
suganya sri
am 13 Nov. 2017
how to find pixel value in somelocation, pls anybody help me
1 Kommentar
Siehe auch
Kategorien
Mehr zu Image Processing Toolbox finden Sie in Help Center und File Exchange
Produkte
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!