Suppression of speckles in color images
Joe Zheng, Kimon P. Valavanis, John M. Gauch · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1992
Color images, just like the formation of gray images, are put through a series of noise- contaminating processes. To obtain reliable results in subsequent image analysis, the noise- suppressing problems in original data must be considered and the signal distortions must be minimized. Generally, noise is suppressed individually in each data channel. In this paper, we first illustrate that this technique generally can not produce optimum results and may even introduce unpredictable color spots (artifacts). In order to preserve color appearance and meanwhile not to smear out objects' boundaries, two algorithms using median type operations are then introduced; one is the scalar median filter and the other one is the vector median filter. Experiments and comparisons of both schemes are included.