Adaptive grid pattern artifact reduction in radiography imaging based on the significant-signal bandwidth

In order to obtain more clear x-ray images, an antiscatter grid, which can absorb the scattered rays, is employed. In the high-resolution direct digital radiography, however, the artifacts due to the grid pattern are visible, and their strength are dependent on the x-ray exposure amount. In this paper, we first analyze the effect of the exposure amount on the grid artifacts by proposing a modulated image formation model, and then, to reduce the grid artifacts, an adaptive filtering algorithm, which can measure the strength of the grid artifacts based on the significant-signal bandwidth, is proposed. Numerical analysis for real x-ray digital images are also conducted with some comparison.