An edge-preserving multigrid-like technique for image denoising

Techniques based on the Well-Balanced Flow Equation have been employed as efficient tools for edge preserving noise removal. Although effective, this technique demands high computational effort, rendering it not practical in several applications. This work aims at proposing a multi-grid like technique for speeding up the solution of the Well-Balanced Flow equation. In fact, the diffusion equation is solved in a coarse grid and a coarse-to-fine error correction is applied in order to generate the desired solution. The transfer between coarser and finer grids is made by the Mitchell-Filter, a well known interpolation scheme that is designed for preserving edges. Numerical results are compared quantitative and qualitatively with other approaches, showing that our method produces similar image quality with much smaller computational time.