The gray level values of the noise pixels are much higher than those of their immediate neighbors. As noise is characterized as high frequency values, low-pass filtering methods, like a median filter, can be used to effectively remove the noise pixels. The median filter deploys a small mask template, which is usually a 3 £ 3 or 5 £ 5 structuring element. The template operation may be calculated by either correlation or convolution operators. The median filter replaces a pixel’s gray level with the median value of its neighborhood. This operation improves on other filtering methods by preserving edges while suppressing