Otsu自适应阈值法作为图像阈值分割的经典算法，在图像处理领域得到了广泛的应用，在其基础上发展起来的2维Otsu阈值法却因为计算时间长而制约了其应用。针对2维Otsu自适应阈值方法计算复杂度高的缺点，通过改变2维直方图上的区域划分，将2维阈值转换为1维阈值，从而提高了2维自适应阈值算法的计算速度。实验结果表明，该算法的计算时间远远小于原始2维Otsu算法，分割效果和原始算法基本一致。

As a classical image segmentation method, Otsu adaptive threshold algorithm has applied widely in image processing. The application of the two-dimensional Otsu threshold algorithm based on the Otsu threshold algorithm has been restricted for the long-paying computation. This paper gives a fast algorithm for two-dimensional Otsu adaptive threshold algorithm that overcomes the disadvantage of high computational complexity. The fast algorithm changes the two-dimensional threshold to one-dimensional threshold by using new area partition method, and enhances the computational speed of the two-dimensional Otsu algorithm. The experimental result has demonstrated that the computational time of the fast method is far less than that of the source two-dimensional one.