Multichannel edge enhancement in color image processing

In the paper, a multichannel edge enhancing filter (MEEF) based on the vector median is introduced for enhancing degraded edges in color images. An input multichannel signal is filtered with three subfilters, and the final output is determined by comparing the outputs of the subfilters and their vector median. Root signal and edge enhancement properties of the MEEF are examined in detail. In addition, the authors discuss line preservation and edge jitter resistance of the MEEF in noisy conditions. Finally, the MEEF is tested with: i) blurred edges caused by unfocusing or fast movement of camera, ii) serrated edges caused by interlaced scan, iii) false color edges caused by channel dispersion. The results show that the MEEF outperforms channelwise edge enhancing filtering in enhancing these degraded edges