Color Differentiation

Dears, I have an image with four different colors as Black,Blue, Green and yellow. How can I represent these colors as 1, 2, 3 and 4 respectively. Please help me earlier.. Urgent

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/29922-why-your-question-is-not-urgent-or-an-emergency

[Walter Roberson]

Why is this matter urgent when I had already answered your question before you posted this?

http://www.mathworks.com/matlabcentral/answers/21717-multicolor-representation

Answer 1

[Image Analyst]

I can't help you earlier than right now. The best I can do is now. You might try either the rgb2ind() function (like Walter suggested in your duplicate question), if you want to have MATLAB take a stab at doing color classification for you automatically, or else have more control over it by using my color classification programs: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862