Face detection by cascade of Gaussian derivates classifiers calculated with a half-octave pyramid

This paper presents a method for object detection based on a cascade of scale and orientation normalized Gaussian derivative classifiers learnt with Adaboost. Normalized Gaussian derivatives provide a small but powerful feature set for rapid learning using Adaboost. Real time detection is made possible by use of a fast integer coefficient algorithm that computes a half-octave Gaussian pyramid with linear algorithmic complexity using a cascade of binomial kernel filters. The method is demonstrated by training a boosted classifier for frontal face detection using standard data sets. Experiments demonstrate that this approach can provide detection rates that are comparable or superior to those obtained with integral images while dramatically reducing the required training effort.