Improved Switching Vector Median Filter for Removal of Impulse Noise from Color Images

Image noise is defined as the random variation of color information or intensity in images. It is recognized as a type of electronic noise. Impulse noise is a “high level-low level” noise that affects an image abruptly. A filtering technique defined as an improved switching vector median filter (ISVMF) is proposed for removing impulse noise from color images in this manuscript. The performance analysis has been done for varied noise densities. Though performance has been shown in terms of Lena images, it delivers improved results irrespective of variation of images. The performance comparison has been done on the basis of standard metrics like peak signal to noise ratio (PSNR) and structural similarity index (SSIM), etc. It is observed that the proposed improved switching vector median filter (ISVMF) provides better results both visually and statistically as compared to the other conventional filtering techniques. This better performance may be due to the fact that the threshold has been localized rather than generalized in the filter resulting in better homogeneity across the various sections of the image.