A restoration method of medical X-ray images based on an extended regression analysis method

In this paper, a restoration method for the X-ray images with optical blurs and quantum mottles is proposed by considering each physical mechanism of the medical X-ray image formation. More specifically, the optical blurs are first deterministically cleared away by using the transfer characteristic of the laser scanner, the characteristic curve of the film, the logarithmic transformation of the optical density and a pseudo-inverse filter based on the point spread function. Next, as a restoration method for remaining quantum mottles, a new extended regression model that may have a little information lack and a simple experimental regression model are derived on the basis of a Bayes' theorem. Thus the quantum mottles were statistically removed. Finally, the restoration method of X-ray images proposed in this paper is applied to those of the actual dental images, and dentists visually evaluate and confirm the effectiveness of these processed images.