Color Histograms

I have been researching different methods for coming up with features from the sets of empty and occupied parking spaces before I create the program to gather these features. The most useful paper that I've found on this subject is called Color Photo Categorization Using Compressed Histograms and Support Vector Machines by Xia Feng, Jianzhong Fang and Guoping Qiu. This paper goes over a bunch of different methods for describing color information in images as well as their methodology for using a support vector machine for classification using the color features described in the previous section. It seems that the MPEG-7 color structure descriptor got the best results and this is what I'm going to read about this in more detail next (specifically, Color and Texture Descriptors by B. S. Manjunath, Jens-Rainer Ohm, Vinod V. Vasudevan, and Akio Yamada).