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Chaque projet soutenu par Gebert Rüf Stiftung est présenté sur le site web de la fondation avec en particulier les données de base du projet. Par cette publication, la fondation informe sur les résultats du soutien accordé et contribue à la communication scientifique au sein de la société.


Recovery of fragmented records using VisualAudio


Für den Inhalt der Angaben zeichnet die Projektleitung verantwortlich.


Diese Rubrik wird erst seit 2010 erfasst.

Données de projet

  • Numéro du projet: GRS-046/05 
  • Subside accordé: CHF 135'000 
  • Consentement: 31.10.2005 
  • Durée: 11.2006 - 08.2008 
  • Champs d'activité:  Innovation an Fachhochschulen, 1998 - 2008

Direction du projet

  • Prof. Dr. Ottar Johnsen
  • Hochschule für Technik und Architektur Freiburg
  • Département d’électricité
  • Boulevard de Pérolles 80
  • 1705 Fribourg (Schweiz)
  • johnsen@eif.notexisting@nodomain.comch

Description du projet

With the funding by the Gebert Rüf Stiftung (project GRS-24/03), we have built a system that can extract the sound from phonographic records without contact. It is called VisualAudio. In this system, we first take a picture of the record and then the film is scanned and the image is processed to extract the sound. The system is used since 2006 to recover records for the RSR (Radio Suisse Romande) archives and others. Extracted sounds can be found on the website (see links).
At the Swiss National Library, we observed the catastrophic shape of many records. It is in especially the case for the direct cut aluminum records when the polyacetate part (that contains the sound) retracts resulting in fragmented records. A similar case appears with glass records.
VisualAudio can be used to save such records. We can already extract the sound from each piece of the "puzzle" and we wanted to design the software that will fit the pieces togetherin order to get the continuous sound of the original record. Additionally, an interpolation has to be performed to suppress the click that will appear at each merge of pieces because the fitting isn't perfect. The linking is not straightforward, as the retractions correspond often to the distance between several grooves. Visually, when looking at the microscope, we can do the linking by looking at the groove properties before and after the cut. The purpose of this project is to design this software to reconstruct the sound from broken pieces in a way similar to the visually very time consuming solution.

Quelles sont les particularités de ce projet?

With this improvement, the VisualAudio system will be able to save much more records than in today's state, in particular the numerous records in very bad shape (mainly fragmented records) that are parts of the sound archives. This will be a great help to the national sound archives as it will allow them to recover records that were considered impossible to save.

Etat/résultats intermédiaires

The software developed has allowed the recovery of sound of records that were considered to be unreadable. It has been demonstrated with records from the archives from Radio Suisse Romande as well as the Phonogrammarchiv of the Austrian Academy of Sciences.
In collaboration with RSR, the Swiss National Sound Archives and other actors in Switzerland, we are establishing a permanent structure to use the system under joint responsibility of our school and the Swiss National Sound Archives. We are very satisfied that the system will be used on a non profit basis to save records both from Switzerland and from foreign countries. We will continue to collaborate with foreign institutions on VisualAudio

It has got a large media and scientific exposure, through newspaper papers, TV and radio programs, talks given at many institutions, scientific papers. It has been a showcase for visitors to our school. It has made collaborations with Berkeley and Mc Gill possible. A very successful collaboration has taken place between Ecole d'ingénieurs et d'architectes de Fribourg, Université de Fribourg, Ecole des arts appliqués de Vevey and the Phonothèque nationale Suisse.


Sound extraction of delackered records, accepted for presentation at the AES 125th Convention in San Francisco, October 2-5, 2008
The Use of the VisualAudio System to Extract the Sound of Delackered Records, accepted for presentation, IASA Annual Conference, 14–19 September 2008, Sydney, Australia

See also:

Revue de presse


Personnes participant au projet

Lionel Seydoux, Ecole d'Ingenieurs et d'architectes de Fribourg, 80 Boulevard de Perolles, CH-1705 Fribourg, Switzerland, tel: (+4126) 429 66 78, fax: (+4126) 429 66 00, lionel.notexisting@nodomain.comseydoux@hefr.notexisting@nodomain.comch

Dernière mise à jour de cette présentation du projet  12.05.2020