请参阅http://bytedeco.org/javacpp-presets/opencv/apidocs/org/bytedeco/javacpp/helper/opencv_imgproc.html
cvFindContours(opencv_core.CvArr image, opencv_core.CvMemStorage storage, opencv_core.CvSeq first_contour, int header_size, int mode, int method)
如何使用CvMemStorage？没有文档