  We provide a fast and accurate scatter artifacts correction algorithm for
cone beam CT (CBCT) imaging. The method starts with an estimation of coarse
scatter profile for a set of CBCT images. A total-variation denoising algorithm
designed specifically for Poisson signal is then applied to derive the final
scatter distribution. Qualitatively and quantitatively evaluations using Monte
Carlo (MC) simulations, experimental CBCT phantom data, and \emph{in vivo}
human data acquired for a clinical image guided radiation therapy were
performed. Results show that the proposed algorithm can significantly reduce
scatter artifacts and recover the correct HU within either projection domain or
image domain. Further test shows the method is robust with respect to
segmentation procedure.
