Patch-based variational image approximation

Abstract

Vector graphic gives us a new solution to the representation of raster images. Among many types of vectorized representations, the most popular is mesh representation, which inherits the benefits of vector graphics. Inspired by mesh, we propose a novel patch-based representation for raster images, in which pixels are partitioned into regions, and pixels belonging to the same region are converted into a 3D point cloud and approximated by a 3D planar patch with proper boundaries in a variational way. The resulting patches are then encoded via a half-edge structure for storage. The key point is that the vertices of boundaries are not located on the very positions of sample points, i.e. converted pixels, but dependent on the optimal position of the patch, which theoretically reduces the fitting errors. Experiments show that our algorithm produces better results.

创新点

1、提出了一种基于块的图像矢量化表达方式,改进了传统对网格顶点颜色值的确定方法,由原来的直接利用所在像素点的颜色值改为由最终的优化结果决定,使得重建效果较之前的方法有所提高;2、算法采用类半边结构编码并存储平面块集合的拓扑信息,使得图像表达简洁高效。