对某些相同灰度级成片连续出现的图像（如洪水图），行程编码也是一种高效的编码方法。特别是对二值图像，效果尤为显著。在一个逐行存储的图像中，具有相同灰度值的一些像素的序列，称为一个行程。-Appear in successive images of some of the same gray level into tablets (such as flood charts), the run length coding is an efficient coding method. In particular, the binary image, the effect is particularly significant. Some of the pixels having the same gray value in the stored image of a progressive sequence, referred to as a stroke.