In this paper the features of the median filter and the Sobel operator are mainly discussed. A pseudo median filter and a Sobel edge sharpening are realized in hardware by use of the water-flow working fashion. The results show that the two methods can filterout image noises and draw the outline real-timely. The filtered image’s SNR increases about 7dB. The time delay is less than 200 μs. In addition

we put forward a new method for noise smoothing. It can protect the edge of images and filter out the pulse noises just as the median filter but better in filtering out the stochastic noises.