Edge-Aware Color Image Manipulation by Combination of Low-Pass Linear Filter and Morphological Processing of Its Residuals

Abstract

In the paper, a method of edge-preserving processing of color images, called LPMPR (Low-Pass filter with Morphologically Processed Residuals), is proposed. It combines linear low-pass filtering with non-linear techniques, that allow for selecting meaningful regions of the image, where edges should be preserved. The selection of those regions is based on morphological processing of the linear filter residuals and aims to find meaningful regions characterized by edges of high amplitude and appropriate size. To find them, two methods of morphological image processing are used: reconstruction operator and area opening. The meaningful reconstructed regions are finally combined with the low-pass filtering result to recover the edges’ original shape. Besides, the method allows for controlling the contrast of the output image. The processing result depends on four parameters, the choice of which allows for adjusting the processed image to particular requirements. Results of experiments, showing example filtering results, are also presented in the paper.