Biomedical image enhancement using different techniques - A comparative study

Abstract

In medical applications, processing of various medical images like chest X-rays, projection images of trans-axial tomography, cineangiograms and other medical images that occur in radiology, ultrasonic scanning and nuclear magnetic resonance (NMR) is required. These images may be used for patients’ screening and monitoring for detection of diseases in patients. Image enhancement algorithms are employed to emphasize, smoothen or sharpen image features for display and analysis. In the biomedical field, image enhancement faces the greatest difficulty in quantifying the criterion for enhancement. Enhancement methods are application specific and often developed empirically. The theme work presented in this paper is a detailed analysis of enhancement of medical images using contrast manipulation, noise reduction, edge sharpening, gray level slicing, edge crispening, magnification, interpolation, and pseudo-coloring. Comparison of these techniques is necessary for deciding an apt algorithm applicable for enhancement of all medical images and further processing. This paper reviews the background of enhancement techniques in three domains i.e. spatial, frequency and fuzzy domain. The comparative analysis of different techniques is shown using results that are obtained by applying these techniques to medical images.