A New Filtering Algorithm for Removing Salt-and-Pepper Noise

A new filtering algorithm for removing salt-and-pepper noise from gradation images was introduced. Eight directional templates and one nondirectional template were selected to smooth gray-scale images. First to judge which templates the pending pixel should belong to according to compatibility and similitude principle, then using the corresponding template to smooth the pending pixel.The salt-and-pepper noise in gradation images can be removed effectively as well as the margins and details can be kept well. This filtering algorithm can be more useful in the field of medical images pretreatment.