Smoothing and Regularization with Modified Sparse Approximate Inverses

Figure 4

Reconstruction error against the iteration for the 1D blur operator 𝐻⁴¹ and the original data 𝑥₂ of size 𝑛=10³ affected by random noise of order 0.1%. CG is compared to CG for the normal equations and to PCG using MSPAI satisfying 𝑅3_𝐺1 with 𝜌=10².