Application of Improved Median Filter on Image Processing

Median filter is the most common method of clearing image noise. This paper proposes improved algorithm of median filter to remove sale and pepper noise of image. According to the characteristics of salt and pepper noise, the algorithm detects image noise, and establishes noise marked matrix, without processing the pixels marked as signal. The signal of the pixel is marked as not treated, labeled according to their pixel noise pollution in the neighborhood to take a different pixel weighted mean filter window size, weight pixel region by the noise points to determine the local histogram. Matlab experiments show that improved median filter can greatly reduce the time of clears image noise and it performs better than median filters on noise reduction while retaining edges of an image.