说明：  用openCV提取图片的象素值，用聚类进行分割，找出各个聚类的中心点，聚类个数是动态决定的，可重新设置个数最大上限。
(OpenCV extract images using pixel value segmentation by clustering to identify the center of each cluster, clustering is a dynamic number of decisions can be re-set the upper limit of the number of the largest.)