A hybrid nonlinear fourth-order PDE-based image restoration approach
Tudor Barbu · 2016
This article is concerned with hybrid image denoising and restoration using partial differential equations (PDE). A compound filtering model combining a nonlinear fourth-order PDE to a two-dimension Gaussian filter is proposed first. The obtained fourth-order diffusion model is discretized by constructing an explicit finite difference method-based numerical approximation scheme. While this combined PDE-based denoising method provides an effective detail-preserving smoothing and overcomes the staircase effect, it could generate the unintended speckle noise. Thus, a more complex hybrid denoising solution is achieved, by adding a despeckling component to the diffusion-based scheme. The resulted hybrid restoration approach removes successfully the Gaussian noise, avoids all the unintended effects and outperforms many state of the art nonlinear PDE denoising models.