Reduction of parasitic pitch variations in archival musical recordings

A new method for reducing parasitic pitch variations in archival audio recordings is presented. The method is intended for analyzing movie soundtracks recorded in optical films. It utilizes image processing for calculating and reducing effects of tape shrinkage being one of the main reasons for parasitic pitch variations in audio accompanying moving images. As long as the film tape characteristics are known the new method can be easily tuned to analyze archival recordings. The new method is also compared to some previous approaches to pitch variation correction.