Affine scaling methods for image deblurring problems

Blur in images can be removed by solving a series of box-constrained linear least-squares problems. In this paper, we compare two recent approaches for solving these problems using affine-scaling methods. Both approaches aim at solving a nonlinear system arising from the Karush-Kuhn-Tucker condition. One approach is to identify the active set and update the inactive components of the iterates by using a Newton-like method. The other is to iteratively solve the nonlinear system entry-wise by a Quasi-Newton method.