OTSU方法计算图像二值化的自适应阈值。OTSU 算法可以说是自适应计算单阈值（用来转换灰度图像为二值图像）的简单高效方法-Otsu images calculated value of the two adaptive threshold. Otsu algorithm can be said to be adaptive to calculate the single threshold (for converting images to gray scale image 2) simple and efficient method