Dear, if you have matlab, it has following code that seperates 3 color
values:
i=imread('sample.bmp','bmp'); % Save Bitmap 24 bit format in Array I
'Loop the value of a starting from 1, and x,y are pixel posistions
r(a) = i(x,y,1);g(b) = i(x,y,2);
b(c) = i(x,y,3); Similarly for Green and blue
Hope u got this....
Brijesh R. Jajal,
(MCA, MCP)
Lecturer in Computer Science,
ARIBAS, New Vidyanagar, 
Gujarat,India. 
Mobile : 09427597769.
Profile: www.aribas.edu.in/Mr.Brijesh.aspx