qqp question1: Algorithms: Why is viola-jones still considered as state-of-art in object detection algorithm? question2: Computer Vision: Easiest way to implement viola jones face detection in java.? I have studied the algorithm i know the working still dont know how to start it with java. I want some code with documentation for reference or some idea how to do training and all that stuff. Provide me some useful links if possible. I have already googled a lot but it seems little bit confusing that's y i m askin here.. thanks in advance.