How to build gradient magnitude-orientation histogram?

We are trying to extract shape features.

[Walter Roberson]

Perhaps Bala has some ideas; http://www.mathworks.com/matlabcentral/answers/25768-building-types-of-histograms

[Ganesh]

could u give me some hints about how to create the spatial correlogram of an image? Has anyone used it for image and got it successfully?