A new method of denoising mixed noise using limited grayscale pulsed couple neural network

A new method of removing mixed noise of Gaussian noise and salt and pepper noise was proposed based on extreme grayscale and pulse-coupled neural network (PCNN). First, salt and pepper noise was identified according to extreme grayscale value and then the noise was removed by mean filter while keeping the noise-free pixels unchanged so the proposed method is effective on preserving the image edges and details. Gaussian noise is identified by using the time matrix of PCNN. Finally Gaussian noise was filtered by adaptively selected filters based on variable step. Experimental results show that the proposed method has advantages in terms of filtering effects, adaptiveness and preserving image details compared to traditional methods.