CONTRAST ENHANCEMENT FOR CT SCAN IMAGE USING LOOK-UP TABLE (LUT) METHOD

• Main Author: Nur Azizah, Rahmalia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/80617
• Institution: Institut Teknologi Bandung

The image obtained from radiology equipment, such as CT Scan, is have a poor contast. This problem could deliver to misdiagnosis. So that, the contrast need to be enhance using contrast enhancement process. One of the most used method in contrast enhancement, is Histogram Equalization (HE) method. But HE method may cause an excessive increase in brightness of the image. Look-Up Table (LUT) method can be used to overcome this. This research was conducted to see the performance of the LUT method in improving contrast. The output obtained will be compared with the output of another contrast improvement method, HE. In this research, the original image whose contrast has been reduced, referred to as the input image, will processed using using both contrast enhancement methods separately and then compare the results using objective parameters, such as Peak Signal to Noise Ratio (PSNR), Root Mean Square Contrast (RMS C), and Absolute Mean Brightenss Error (AMBE). As for the LUT method, thresholding will first be carried out using the Multi-Otsu Thresholding method before applying the transfer function to the input image. As the result, LUT method delivers a good result in contrast enhancement, compared to HE method, which larger gap between threshold ????1 and ????2 will give an output image with better quality.