Modulation model for the analysis of the stationary grid artifacts in digital radiography imaging

In this paper, in order to analyze the grid pattern artifacts, which are caused by using the antiscatter grid in obtaining x-ray projected images, we propose a multiplicative image formation model comparing to the traditional additive model. Through the proposed model, we show that the projected image is a summation of the modulated signals and, instead of using a narrow-bandwidth notch filter, a band-rejection filter should be employed. We also theoretically show the maximal resolution of the recovered images without grid artifacts, and through simulations using real x-ray images, observe the practical meaning of the theoretical analysis.