http://docs.opencv.org/2.4/modules/imgproc/doc/structural_analysis_and_shape_descriptors.html

http://blog.csdn.net/shouhuxianjian/article/details/42686395

http://blog.csdn.net/shaoxiaohu1/article/details/40272875

http://mobile.51cto.com/aengine-435442.htm

findContours

contourArea

boundingRect

轮廓提取