Analog adaptive median filters

The implementation of analog adaptive median filters for image processing is presented. The adaptive median filter is based on transconductance comparators, which saturation current is adapted to act as a local weight operator. Transistor level simulations, using 1.2mm parameters, have shown excellent results in high removing incidence noise. An image with 249 × 209 corrupted with 35% salt and pepper noise, is used to test the adaptive median filter. All the simulations were made using BSIM3 level 49 model and 1.2 mm MOSIS parameters.