Color Median Filtering: a Spatially Adaptive Filter

This paper deals with median filtering techniques suitable for digital color images. Median filters have successfully been used in gray scale imaging to remove impulsive noise but their extension to color images is not direct. The main difficulty is that an order has to be defined to sort the color vectors. In this paper, we selected four classical different and well established approaches proposed during the last years to use median filters in color image processing. We also introduce and describe an alternative and adaptive methodology for color median filtering. Experimental results for classical techniques and for our methodology are analyzed and compared. These results show that the method we propose can effectively remove impulsive noise while preserving fine structures of color images. Furthermore, the process is really fast and can be used for video filtering in real time.