Selective image-sharpness enhancement by coupled nonlinear reaction-diffusion time-evolution and its practical application

This paper presents a method for selective sharpness enhancement that can sharpen only degraded edges blurred by several causes without increasing the visibility of nuisance factors such as random noise. The method is based on the coupled nonlinear reaction-diffusion time-evolution equipped with a second-order nonlinear smoothing term, a reaction term and an overshooting term. The quantitative performance evaluations demonstrate that the method sharpens blurred edges selectively much better than the existing sharpness enhancement methods such as the peaking method and the Volterra filter method. Moreover, this paper applies the method to the real problem of the breathing-distortion removal.