OBJECT-BASED 3D BINARY RECONSTRUCTION FROM SPARSE PROJECTIONS IN CONE BEAM CT: COMPARISON OF THREE PROJECTION OPERATORS

We present herein a level set approach to the X-ray tomography problem with sparse projection data and study the impact of the pro-jection operator on the binary reconstruction accuracy and compu-tation time. The comparison is carried out on three projectors: the Separable Footprint (Trapeze-Trapeze, SF-TT) [3], a classical Ray-driven (RD) and a Simplified version of the Distance-Driven (SDD) projector respectively. The performance, are evaluated for each op-erator, on a binary 3D Shepp-Logan phantom by varying the number of projections from 5 to 13, and considering noise free and noisy cone beam projection data. Index Terms — cone-beam geometry, projection operator, 3D it-erative Reconstruction, object-based reconstruction, level set. 1