High Density Salt and Pepper Noise Removal Using Adapted Decision Based Unsymmetrical Trimmed Mean Filter Cascaded With Gaussian Filter

An adapted decision based unsymmetrical trimmed mean filter cascaded with Gaussian filter (ADBUTMF) algorithm for the retrieval of gray scaled image which is induced by a very high density Salt and Pepper (impulse) noise is proposed and tested in this paper. The proposed algorithm replaces the noisy pixel by trimmed mean value when other pixel values, 0s and 255s are present in the selected window and when all the pixel values are 0s and 255s then the noise pixel is replaced by mean value of all the elements present in the selected window. This proposed algorithm shows better results than the Standard Median Filter (MF), Decision Based Algorithm (DBA), Modified Decision Based Algorithm (MDBA), Progressive Switched Median Filter (PSMF) and Modified Decision Based Unsymmetrical Trimmed Median Filter (MDBUTMF). The proposed algorithm is tested against different grayscale and color images and it gives better Peak Signal-to-Noise Ratio (PSNR).