An accelerated projection algorithm in image reconstruction
DANG Yazheng
CAO Qian
Hou Shouming
Abstract：The projection algorithms mainly including projection onto convex sets algorithm and parallel projection method are the most pervasive tools for solving convex set image reconstruction problem.In the former of these two algorithm,an initial estimate is sequentially projected onto the individual sets according to a periodic schedule.While in the latter,the calculations of the projections onto all sets at each iteration are required.Although parallel projection method improves the convergence speed through the parallel operation,but iteration step-size is still limited in the interval(0,2) at each iteration,which affects its convergence.In order to seek the accelerated projection algorithm with better convergence and better reconstruction,an accelerated projection algorithm is proposed by introducing an extrapolation factor on the basis of parallel projection method (PPM),and the convergence is proved under certain conditions.This new algorithm makes the step-size larger than 2,and it ensures that each iteration is closer to the solution set.The experimental results show that the accelerated projection algorithm converges more quickly and more efficient than PPM.
Keywords：image reconstructionprojection onto convex setsprojection algorithmconvergence
Publication Date：2018-03-02
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 104-108 )