Adaptive impulse detection using center-weighted median filters

Previous median-based impulse detection strategies tend to work well for fi xed-valued impulses but poorly for random-valued impulse noise, or vice ver se. This letter devises a novel adaptive operator, which forms estimates ba sed on the differences between the current pixel and the outputs of center- weighted median (CWM) filters with varied center weights. Extensive simulat ions show that the proposed scheme consistently works well in suppressing b oth types of impulses with different noise ratios.