Flash X-Ray Radiographic Image Restoration by Wiener Filter Method

Some blurred images taken by a flash X-ray system have been restored successfully. A radiography model is built by the approximation of LSI system. United PSF is presented to describe the blur effect of the system and measured by pinhole or step sample experiment successfully. Before calculation, some pre-processing is necessary for giving a good result, which includes the adjusting of nonlinear information and the weakening of various noises. Wiener filter method requires that the signal-to-noise ratio (SNR) of the blurred image can be lifted up to 30~50. If the blurred image is a section and without a blurred boundary, it is necessary to add a blurred boundary approximately. Let pn(u,v)/pf(u,v)k, result shows that the restoration is as good as that in the case pn(u,v)/pf(u,v) is accurate, so long as we select an appropriate k, k can be obtained by 1~2 times test. Generally k=0.1~0.001. A restoration result is given with k=0.002.