Image Sharpness and Contrast Enhancement with Noise Reduction using Logarithmic Image Processing Model with Modified Decision based Unsymmetric Trimmed Median Filter

Image enhancement is basic problem in the field of image processing & it can be subdivided into many categories like edge enhancement, smoothing, contrast enhancement, bright enhancement, sharpness enhancement etc. The classical approach treats the operations using linear systems which creates many computational problems and also does not match to human visual perception and interpretation logic. In this work we propose a LIP (Logarithmic Image Processing) technique in combination with MDBUTMF (Modified Decision Based Unsymmetric Trimmed Median Filter) for contrast and sharpness enhancement with capability to suppress the noise. LIP uses non-linear operations for image manipulation which are computationally effective. In LIP, image processing specific arithmetic operations are introduced which ensure that there is no loss of information in the form of ―out-of-range‖ pixel values. MDBUTMF is a very efficient median filter and it is capable of de-noising images which are corrupted with high density salt and pepper noise. Thus the combination of these techniques results in an efficient image enhancement algorithm. MDBUTMF is first applied to de-noise the input image. The de-noised image is further processed by LIP based enhancement methods to generate the final output. All the implementation work has been done in MATLAB 10.0 image processing tool box. Simulation results show a marked improvement in performance in terms of removal of noise, contrast, sharpness, detail enhancement, and Overall quality of image as compared to existing algorithms.