From DxO:
01/23/2013 - Version 1.1.1 of DxO ViewPoint, the software solution entirely dedicated to correcting keystoning as well as deformations caused by the use of wide-angle lenses, fixes various minor problems caused by extreme perspective corrections.
Based on DxO Labs’ advanced geometrical corrections, DxO ViewPoint corrects the distortion of the subjects on the edges of images — known as “volume anamorphosis” — due to the use of short focal lengths (as with wide-angle lenses). DxO ViewPoint also lets users correct the most complex kinds of perspective problems, including keystoning, without having to resort to costly shift lenses. Each of these features includes advanced fine-tuning controls to achieve the highest correction precision.
DxO ViewPoint can be used as a standalone application for Mac and Windows, and as a plugin for Adobe® Photoshop® CS3, CS4, CS5, CS6, and Adobe® Photoshop® Lightroom® 3 and 4.
This upgrade is free for all owners of DxO ViewPoint v1.0.
B&H carries DxO Viewpoint software.