- A new method of calculating the optical transfer function (OTF) for image blur caused by arbitrary motion is introduced. Previous methods, except for a few specific types of motion, were numerical rather than analytical. This new method makes it possible to obtain analytical expressions for OTF, deriving from any kind of motion, by means of the statistical moments of the motion function. Analytical OTF expression are derived for high and low- frequency vibrations. An example of implementation of the method in restoration of images blurred by motion is presented.