特征提取的原理、代码等；
如果是白黑白，是减去一个黑的还是2个黑的，网上有不同的说法；应该需要看原论文了。
论文原文
The sum of the pixels which lie within the white rectangles are subtracted from the sum of pixels in the grey rectangles.
A three-rectangle feature computes the sum within two outside rectangles subtracted from the sum in
参考
1.Haar-like特征提取原理；
2.计算Haar-like特征数目；
3.VJ大神论文；
完
