Please can you tell me Algorithm to count the number of white pixel ?
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i want algorithm to count the number of white pixels, please .
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Answers (2)
Image Analyst
on 11 Apr 2014
How do you define "white". Have you checked out my color segmentation demos in my File Exchange? http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862
In the special specific case where you have a gray scale image (not color) and want to just count the number of pixels at exactly 255, you can do this:
whitePixels = grayImage == 255; % Produces a binary (logical) image.
count = sum(whitePixels(:))
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Jotheeshwar V
on 4 Jul 2018
%
imread color.jpg
load color.jpg
redChannel = color(:, :, 1);
greenChannel = color(:, :, 2);
blueChannel = color(:, :, 3);
whitePixels = redChannel == 255 & ...
greenChannel == 255 & ...
blueChannel == 255;
count = sum(whitePixels(:));
Red1Pixels = redChannel == 255 & ...
greenChannel == 166 & ...
blueChannel == 166;
count = sum(Red1Pixels(:));
Red2Pixels = redChannel == 254 & ...
greenChannel == 85 & ...
blueChannel == 82;
count = sum(Red2Pixels(:))
Blue1Pixels = redChannel == 179 & ...
greenChannel == 169 & ...
blueChannel == 250;
count = sum(Blue1Pixels(:))
Blue2Pixels = redChannel == 255 & ...
greenChannel == 255 & ...
blueChannel == 255;
count = sum(Blue2Pixels(:))
This my complete code.
This might be useful for you people to help me.
-Jotheeshwar
Jan
on 4 Jul 2018
Walter Roberson
on 11 Apr 2014
In a greyscale image, every pixel that is not absolute black is arguably white of some brightness or other. Therefore you can count the number of non-zero pixels to get the answer. Fortunately, MATLAB has a call nnz() that does that for you.
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