A high-order prior for overlapped projections in the real flat-panel x-ray source imaging system

With the appearance of the field-emission cold cathode x-ray source, the fast response and small in size innovate the traditional imaging system. Although the field-emission x-ray source array generates multiple novel imaging modalities, it still faces a long stand-off distance between source and object. To realize a portable, smart, extremely low dose imaging modality, researchers proposed a concept to design a two-dimensional array field-emission source, namely the flat-panel source. In this paper, a real imaging system based on the ZnO field-emission flat-panel source is designed. Currently, the real flat-panel source faces an extremely low dose and non-addressable situation. Hence, the measurement based on the flat-panel source is overlapped and without an application potential. We first try to realize the imaging ability of the flat-panel source by designing a rebinning algorithm. With the analysis on the overlapped measurement, a high-order prior is introduced into the rebinning algorithm to improve the performance. Simulation and real data experiments verified our proposed method. Compared to the no high-order prior, the proposed algorithm can recover a more distinct measurement.