Nonlinear filtering impulse noise removal from corrupted images

The alpha-trimmed mean (ATM) filter is introduced and a median-weighted ATM (MWATM) filter is proposed to detect and remove impulse noise from corrupted images by combining them with a modified iterative switching scheme. It is shown that although the ATM filter may not perform better than the median filter in impulse noise removal, it is a better impulse detector. The MWATM filter is generated by set the weight of the median value in the ATM filter as a filtering parameter instead of one. Simulations show that the optimum weight of the median value does not equal to one in general. We also noticed that the iterative switching scheme used by Zhang and Wang [6] is not optimized. A modified version of it is therefore proposed.