An Iterative Approach To Sinogram Restoration
We present a projection-space method for reconstruction from limited-angle, sparse-angle, and noisy projections. A variational problem, formulated in projection-space; incorporates consistency of the projections using constraints, convex support as a penalty on sinogram values, and sinogram smoothness through spatially varying horizontal and vertical smoothing coefficients. Specification of the vertical smoothing coefficient requires the convex support and an a priori expectation of the object's profile within its convex support. The horizontal smoothing coefficient is chosen heuristically to help account for the absence of observed projections.