Analysis of histogram based compound contrast enhancement with noise reduction method for endodontic therapy

Radiographs are essential to all phases of endodontic therapy. They inform the diagnosis and the various treatment phases and help evaluate the success or failure of treatment. Because root canal treatment relies on accurate radiographs, it is necessary to master radiographic techniques to achieve films of maximum diagnostic quality. Such mastery minimizes retaking of films and reduces the radiation exposed on patient due to which image quality is low contrast. Hence, image processing techniques are an acceptable technique that can be used to improve the quality of image to assist dentist for diagnosis. Digital dental radiograph images are often noisy, blur edges and low in contrast. We have proposed the combination of sharpening and enhancement method to overcome these problems. The impulse noise is reduced by using median filtering technique. Then filtered image is passed through the homomorphic filter to improve the image illumination. The processed dental images for root canal teeth are contrast enhanced by sharp contrast adaptive histogram equalization. The combination of median and homomorphic filter with SCLAHE is compound contrast enhancement method. The results are verified in terms of peak signal to noise ratio (PSNR) and entropy of image.