An Improved Contrast Enhancement Approach for Panoramic Dental X-ray Images

The Panoramic Dental X-ray image is an important tool for a thorough dental examination. These X-ray images suffer from poor contrast because of the luminance non-linearity introduced by medical imaging techniques. Hence an automatic method of image enhancement of panoramic X-ray image is essential. A novel method of improving the quality of these images is determined based on gamma correction using GLCM (Gray level co-occurrence matrix) by minimizing the homogeneity feature and by computing a global gamma value based on cumulative histogram without any knowledge of the imaging device. The performance of both the methods is compared in terms of metrics like MSE, PSNR & AMBE and it is illustrated that gamma correction based on GLCM by minimizing the homogeneity yields better results in terms of low MSE, high PSNR and low AMBE.