画线的算法不少，但要作到高速、简单并不容易。斜率相乘法是最简单的方法之一，但计算每个点均要花费不少时间用于乘、除法运算；下面介绍的是Bresenham s高效画线算法，对每个点的坐标计算只要加、减法就能完成。-line drawing algorithm, but a lot to be done fast, simple is not easy. The slope is the most simple multiplication is one of the ways, but each p

实现遥感图像的四则运算，包括图像的加法，减法，乘法和除法。-This program can achieve the image computation, including add, subtract, multiply and divide algorithm.