Ultrasound Image Enhancement using Histogram Equalization Followed by Frequency Domain Filters

The goal of image enhancement technique is to improve a characteristics or quality of an image, such that the resulting image is better than the original image. Image filtering before image enhancement is always the root process in many medical image processing applications. It is aimed at reducing noise in images. Common enhancement technique like Histogram Equalization has been used including the various frequency domain filters such as Gaussian filter, High boost filter, Laplacian filter, Lee filter, Kaun filter, High pass kernel filter, Low pass kernel filter and Median filter. The technique applied was assessed by measuring the image quality by calculating the MSE and PSNR of the image and applying the enhancement technique to the output images. In conclusion, for ultrasound liver image, median filtering seems to be the best option in enhancing the image compared to the other filters. Experimental results show that the method can effectively improve vision quality of image and assist doctor in clinical diagnosis.