Abstract: In conventional radiography imaging, the visibility is often limited due to the superimposition of the structure of the object and scattered X-rays. As to this problem, an image enhancement algorithm based on a simple radiography scattering model improves the visibility of a single X-ray image. Firstly, the X-ray image was restored according to the simple radiography scattering model. A new median filter was added in the restoration process, which can effectively suppress the pulse noise component in the X-ray image. At the same time, the guided filter was applied to the transmission image before refining, and the effect of the edge part where the gray value jumps was improved, and the halo artifact was minimized. Finally, The restored image was post-processed by a gray optimization method, which conserves the small details of the image and improves the contrast. The experimental results show that the proposed algorithm is effective for low contrast and low brightness X-ray images. And the structure of the detected casting is clearer in the enhanced image, thus the visibility of X-ray images was improved greatly.