Abstract: A free-form image stretching algorithm is presented. By establishing a linear mapping from destinate image to the original image, the algorithm utilizes the rasterlization algorithm of polygons to accomplish the stretch. The algorithm can stretch an original rectangular image into an arbitrary quadrangle. In this algorithm, many basic geometric transformations of digital images are unified. These transformations include scaling, rotating, shearing, flipping, and mirroring, etc. The algorithm can also support some complex geometric transformations by using the image subdividing technique. An example of this is given.

Key words: image warping, geometric transformation, computer graphics, algorithm

摘要： 描述了一个基于线性变换的图像自由拉伸算法。此算法在多边形扫描转换算法的基础上，以线性变换的方法，可以将矩形的原始图像拉伸至任意定义的四边形形状，从而使得常用的图像几何变换在此算法中得到了统一。用这个算法可以处理的图像几何变换包括：图像旋转，图像变倍，图像剪切，以及图像翻转，镜像变换等。使用本文所述的算法，结合图像的网格划分技术，可以实现更为复杂的图像几何变换，例如矩形图像向任意曲边四边形的变换，透视变换等。

关键词: 计算机图形学, 图像的几何变换, 算法, 桌面电子出版与印刷