Research Of Digital Radiography Image Quality Assurance

In X-ray industrial NDT inspections, for the reason of low cost and high resolution, film inspection has been applied in everywhere of industrial field. But the shortcomings of film inspection are complicated operation process which is operable only for experienced operators, low inspection efficiency and hard for storage and archive.But digital X-ray inspection can have the same level of image resolution as film, and further can achieve larger dynamic range and higher efficiency. The real-time digital system can have higher precision of image location and with suitable digital image process methods, also can have better image contrast and resolution. The digital images can be properly stored and transported. But by effects of high-voltage rectifier, noises while shooting and etc. All these factors can occur to a result that the image quality would be reduced. Below are the points of this paper for researching on image quality assurance.1. Researched X-ray equipment hardware structure, to aim at the main factor in X-ray equipment, high voltage rectifier, proved by theoretic and practical comparison that constant potential rectifier was superior to self-rectifier.2. Through optimum design for scattering filtering, secondary X-ray shielding, projection geometry distribution and penetration parameters by IQI testing, the better parameters could be known.3. From the analysis of X-ray image principle, through the comparable study of image intensifier and digital flat panel and corresponding image quality, realized digital flat panel had more advantages than image intensifier.4. To focus on image features, different kinds of noises and actual inspection request, through comparable study of every digital image process methods to reduce the noise and enhance image, proved suitable methods mentioned in this paper.