How to convert the green pixels to white?

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I have this image labelled dark green(In the image attached). I want to turn all of the pixels that are not black to white. How do i do that?

Accepted Answer

Walter Roberson
Walter Roberson on 20 Mar 2016
%black pixels have 0 for all 3 components, R, G, B. So a non-black pixel has at least one non-0 component
mask = any(YourRGBImage,3); %true if any component is non-zero
%now that we know which ones are non-black, make those pixels white
%ah, short-cut: since logical true is 1 and white is 1, and logical false is 0 and black is 0
%we can just use the mask itself as the black / white image
maskedImage = double(repmat(mask, 1, 1, 3));
  3 Comments
charuleelaa vanilavarasu
charuleelaa vanilavarasu on 21 Mar 2016
Edited: charuleelaa vanilavarasu on 21 Mar 2016
How do i do the reverse? i.e Turn all the black pixels white? would imcomplement work?

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More Answers (1)

Image Analyst
Image Analyst on 21 Mar 2016
I hve several color segmentation demos in my File Exchange. http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862 Adapt one of them to find pixels that you consider to be of a roughly or exactly "green" color. This will give you a mask of what pixels are green.
If you really want to "I want to turn all of the pixels that are not black to white." then it really doesn't matter if they're green or purple or yellow or any other color to start with, does it? In that case, use Walter's code to turn non-pure-black pixels to white.
  4 Comments
charuleelaa vanilavarasu
charuleelaa vanilavarasu on 21 Mar 2016
Edited: Walter Roberson on 21 Mar 2016
Image1=im2double(filt);% filt is the filtered image
[row column page] = size(Image1)
mask = Image1(:,:,2) > Image1(:,:,1) & Image1(:,:,2) > Image1(:,:,3);
Image2 = Image1 .* mask(:,:,[1 1 1]);
figure,imshow(Image2);
title('light green');
mask = Image2(:,:,2) + 50 > Image2(:,:,1) & Image2(:,:,2) + 50 >
Image2(:,:,3);
Image3 = Image2 .* mask(:,:,[1 1 1]);
figure,imshow(Image3);
title('dark green');
This is what i used to get those pixels detected. It's supposed to detect vegetation in an image. Doesn't work perfectly but works to an extent.
Image Analyst
Image Analyst on 21 Mar 2016
You might be better off segmenting on hue in HSV color space. See the tutorial in my File Exchange.

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