A comparison of face and facial feature detectors based on the Viola–Jones general object detection framework

The human face provides useful information during interaction; therefore, any system integrating Vision-Based Human Computer Interaction requires fast and reliable face and facial feature detection. Different approaches have focused on this ability but only open source implementations have been extensively used by researchers. A good example is the Viola–Jones object detection framework that particularly in the context of facial processing has been frequently used. The OpenCV community shares a collection of public domain classifiers for the face detection scenario. However, these classifiers have been trained in different conditions and with different data but rarely tested on the same datasets. In this paper, we try to fill that gap by analyzing the individual performance of all those public classifiers presenting their pros and cons with the aim of defining a baseline for other approaches. Solid comparisons will also help researchers to choose a specific classifier for their particular scenario. The experimental setup also describes some heuristics to increase the facial feature detection rate while reducing the face false detection rate.