Image Processing for Illumination invariance and shadow removal

Hi everyone, I am working on image processing for illumination invariance and shadow removal. I used the concept of this ( http://www.mathworks.com/matlabcentral/newsreader/view_thread/262429) thread with some modifications. While I could easily achieve this on synthetic images such as one generated by POVRAY. It fails completely for real time images. These images could be viewed here: http://himali-himalayas.blogspot.com.au/

Anyone has better image processing technique for illumination invariant and shadow removal technique with code? Thanks for your help in advance.