Shadow Detection

Illumination invariant shadow detection

An illumination invariant shadow ratio is introduced. The invariant is calculated using RGB information.
The threshold value needs to be tuned by user for the test images.
A test image is included.
% For Academic & Educational Usage Only
% Please consider citing following reference articles.
%
% B. Sirmacek and C. Unsalan, "Damaged Building Detection in Aerial Images
% using Shadow Information", 4th International Conference on Recent Advances
% in Space Technologies RAST 2009, Istanbul, Turkey, June 2009.
%
% C. Unsalan and K. L. Boyer, "Linearized vegetation indices based on a formal
% statistical framework," IEEE Transactions on Geoscience and Remote Sensing,
% vol. 42, pp. 1575-1585, 2004.