Abstract: The internal energy of the Snake is used as the prior model of the level lines of the image, and its descent flow is an evolution equation of the level lines. From this equation we obtain the evolution equation of the image surface using the connection of the surface evolution and its level lines. In this paper, we apply the curve and surface evolution equation to image zoom. The geometry meaning of this zoom method is to choose among W the image that has the smallest internal energy of the Snake. Experiments shows that better results will be obtained in a comparable computing velocity.

Key words: Image zoom, curve evolution, surface evolution, Snake model

摘要： 本文用Snake内部能量作为图像水平线的先验模型，其梯度下降流是一个关于图像水平线的演化方程。由这个演化方程，利用曲面演化和其水平线演化之间的关系，得到关于图像曲面的演化方程。用这个曲线曲面演化方程进行图像放大，其几何意义是在空间W 中选择使图像的Snake内部能量最小的放大方法。实验表明，本文的方法在相当的时间内可以得到更清晰的放大结果。

关键词: 图像放大, 曲线演化, 曲面演化, Snake模型