The Low Light Photography Field Guide

Repairing Motion Blur

Going back to the types of blur identified on pages 84–91, the key difference between focus blur and motion blur from the point of view of repairing them is not how they were caused, but rather the shape of the blur.

The Point Spread Function for focus blur gives a radial pattern—from point to disc, in other words—but motion blur is unidirectional and at a particular angle. You could say that both focus and motion blur are versions of the same effect, and for repairing them the software problems are similar.

The procedure, too, is similar. First the motion blur has to be calculated; in terms of how many pixels in length and in what direction, measured as an angle. Then the software has to attempt to move edge-defining pixels ...