How Do I remove the green background and replace with white (255)?

Hello, I want to remove the green background from this image and replace it with white. I got so far as extracting all three color channels.

Answer 1

[Image Analyst]

See my color segmentation demos http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

Then get a mask for the "green" pixels and replace

% Make masked pixels white
redChannel(mask) = 255;
greenChannel(mask) = 255;
blueChannel(mask) = 255;
% Recombine separate color channels into a single, true color RGB image.
rgbImage = cat(3, redChannel, greenChannel, blueChannel);