How to convert the green pixels to white?

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?

[Walter Roberson]

No image was attached

Answer 1

[Walter Roberson]

%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));

[charuleelaa vanilavarasu]

it says too many input arguments for repmat

[charuleelaa vanilavarasu]

syntax error. fixed it! thank you!

[charuleelaa vanilavarasu]

How do i do the reverse? i.e Turn all the black pixels white? would imcomplement work?

Answer 2

[Image Analyst]

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.

[charuleelaa vanilavarasu]

I already have the image with the green pixels detected and the others turned black. Now i want to convert only those green pixels to white.

[Image Analyst]

How are they detected? Just set those pixels to 255. I guess I don't/can't understand your difficulty until I see in what forms you have your RGB image and your segmented image.

[charuleelaa vanilavarasu]

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]

You might be better off segmenting on hue in HSV color space. See the tutorial in my File Exchange.