Sound Recovery from Gramophone Records by 3D Reconstruction

Preserving the invaluable historic recording on gramophone records, whether it is speech or music, makes a lot of sense in our societies, because the traditional record play back system wears out the record gradually or even destroys some of the most fragile sample in the archives. This book presents a non-contact method to reproduce sound signal from gramophone records using 3D scene reconstruction of the micro-grooves carved on a record surface. An optical flow based framework for a record playing system is presented. A robust estimation method of computing the surface orientation was built into the framework following the 3D reconstruction process. The sound signal was recovered from the surface orientation and processed further using the industry standard RIAA filter which was also implemented as a digital filter. The overall algorithm has been tested and found to be working correctly using both simulated data of record groove images and that of real groove images.