Several areas like remote sensing, biomedical analysis, and computer vision require good image contrast and details for better interpretations and diagnosis's. In the literature various image enhancement algorithms have been proposed to improve the perceptual aspects of the image for poorly contrasted images. The perceptual appearance of an image may be significantly improved by modifying the high frequency components to have better edge and detail information in the image. The proposed scheme is a modification of simple unsharp mask image enhancement technique.We propose a simple method to improve the pitfalls of the existing unsharp mask technique. The idea is to remove impulsive noise while preserving the edges and to have better contrast for visual perception. Comparative analysis on standard images at different noise conditions shows that the proposed scheme, in general, outperforms the existing schemes with better results.

Key words : Image enhancement, contrast enhancement, unsharp masking, impulsive noise removal