A simple face detection algorithm with sliding window detector
This is a face detection method introduced in Dalal and Triggs 2005. The method has the following steps:
- load 36 x 36 images with face as positive training data, and load random images with face as negative training data;
- normalize them, and produce the histograms of oriented gradient for both images set;
- build a linear classifier for the positive and negative HoG features using support vector machine, with low true negative rate;
- for the test set, scale the image to smaller ones and run through the linear classifier. All the combined bounding box and confidence level builds the detector.