Noise Removal Using Smoothed Normals and Surface Fitting
Marius Lysaker, Stanley Osher, Xue‐Cheng Tai · IEEE Transactions on Image Processing · 2004
In this work, we use partial differential equation techniques to remove noise from digital images. The removal is done in two steps. We first use a total-variation filter to smooth the normal vectors of the level curves of a noise image. After this, we try to find a surface to fit the smoothed normal vectors. For each of these two stages, the problem is reduced to a nonlinear partial differential equation. Finite difference schemes are used to solve these equations. A broad range of numerical examples are given in the paper.