Using the opencv_traincascade application I have trained a cascade classifier using Haar features for car detection. The detector is working pretty good, but I am wondering what kind of rectangle features were selected using AdaBoost. In other words, I want to visualize the features in the same way Viola and Jones are doing in their paper for face detection. However I find the cascade.xml file not so trivial to interpreted, so I was wondering whether there is a way to visualise the 'learned' rectangular features?