Bipolar Impact Noise Removal Method for Color and Black-and-White Images Using Generalized Nonlinear Filter

In this paper, a bipolar pulse noise cancellation method for color and black-and-white images is presented. In this method, first the noise pixels are identified and then based on a special algorithm, the color code value of the noise pixel is replaced with the value that is calculated based on the pixels of its neighbors. First, the value of each pixel is compared to the numbers zero or ۲۵۵. If the pixel in question had values between zero and ۲۵۵, that pixel is noise-free and no operation is performed on it. If the pixel in question has a value of zero or ۲۵۵, then a ۳ * ۳ window is considered around it and the amount of adjacent pixels is examined. If more than half of the neighboring pixels are not noisy, then the value of the pixel in question is replaced by the median value of its neighbors. If the noise intensity is high, and the number of noise pixels around the pixel in question is more than half the number of neighboring pixels, the window will be larger and the algorithm will eliminate noise and replace the noise pixel values in a wider range. Finally, we simulate and evaluate the proposed method in MATLAB software by writing the program code to show its performance.

Keywords:

Pepper-salt noise , Gaussian noise , Middle filter , RGB images , Alpha trim filter , Noise density , Generalized nonlinear filter.