How to normalise the elements of R-B feature image to the range of 0-255

Help Me..its urgent

Answer 1

[Image Analyst]

Try this:

% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
rMinusB = 255 * mat2gray(double(redChannel) - double(blueChannel));