Medical Image Enhancement Techniques

Abstract

Computed tomography (CT) is used to diagnose diseases and tumors. A special dye called contrast material is used in CT scans to assist emphasize the parts of the body being examined. Therefore, an enhancement technique to improve CT images' degradation is needed. This paper aims to present a method to enhance the quality of Ct-Scan images based on discrete wavelets transform and the Retinex algorithm. The proposed methods are based on the Retinex algorithm parameters or Dark Channel Prior algorithm parameters, according to the output image from preprocessing and discrete wavelets algorithm steps to increase the lightness degree of an image, remove possible noise from the image improve the contrast. The results of experiments of the enhanced image outputted from the Retinex model compared with one outputted from the Dark Channel Prior method. Hence, image quality based on the DCP method is a higher degree of enhanced rate and reasonable rate of noise removal-based enhancement measures, which were SI, MSE, IQI, SNR, and SNR, but was very attentive to the percentage values of IQI and SI. So the DCP with WT was recorded as the highest rate of enhancement. Index Terms— Dark Channel Prior, Image quality assessment, Liver CT, Retinex model, Wavelet Transform.