Removal of fixed value impulse noise using improved mean filter for image enhancement

In this paper we have introduced a new method for the enhancement of gray scale images, when images are corrupted by fixed valued impulse noise (salt and pepper noise). Our proposed method gives a better output for low-density impulse noise as compare to the other famous filters like Standard Median Filter (SMF), Decision Based Median Filter (DBMF) and Modified Decision Based Median Filter (MDBMF) and so on. In our proposed method we have improved the Image Enhancement factor (IEF), Peak signal to noise ratio (PSNR), visual perception and also reduce blurring in the image. The proposed algorithm replaces the noisy pixel by trimmed mean value. When previous pixel values, 0's and 255's are present in the particular window and all the pixel values are 0's and 255's then the remain noisy pixels are replaced by mean value. Different gray-scale images are tested via proposed method. The experimental result shows better Peak Signal to Noise Ratio (PSNR) value, Image Enhancement Factor (IEF) and with better visual and human perception.