Physical and chemical changes can degrade the visual color appearance of old paintings. Five digital color restoration techniques, which can be used to simulate the original appearance of paintings, are presented. Although a small number of color samples is employed in the restoration procedure, simulation results indicate that good restoration quality can be attained

A nonlinear multichannel digital filter is presented in this correspondence. The output is a weighted sum of all samples in the filter window, with a single parameter controlling the filter nonlinearity. Although input data ordering is not required, performance can surpass the performance of other ordering-based multichannel filters

Many old paintings suffer from the effects of certain physicochemical phenomena, that can seriously degrade their overall visual appearance.Digital image processing techniques can be utilized for the purpose of restoring the original appearance of a painting, with minimal physical interaction with the painting surface. In this paper, a number of methods are presented which can yield satisfactory results. Indeed, simulation results indicate that acceptable restoration performance may be attained, despite the small size of painting surface data utilized.