The Restoration Of Rory O'More

Irish Film Archive

The Irish Film Archive (IFA) acquires, preserves and makes permanently accessible Ireland's film and audiovisual heritage. Its holdings include an extensive collection of film and magnetic tape, film stills and posters, a paper archive, film equipment and memorabilia. Material from the Archive collection is screened on a monthly basis in the Irish Film Institute cinemas.

To establish a link between the Irish Film Archive and the SIGMEDIA group, Dr. Anil Kokaram proposed to restore an old Irish movie from the beginning of the 20th century. The movie, named Rory O'More and produced by Sydney Olcott in 1911, needed a strong restoration procedure. Different recent automatic restoration processes were employed. A public presentation of the results was performed by Dr. Anil Kokaram the 4th of September 2002 in the Irish Film Institute (previously the Irish Film Centre) in Dublin. Here are the posters presented at the Institute:

The movie

Rory O'More was an Irish hero, leader of the rising of 1641 in Ireland against King of England Charles I. The movie relates the events of his capture and his escape. The movie contains some 12291 frames in poor state of preservation. The figure [fig1] shows some of these frames. The frames are 720x576 pixel each. Severe degradations appear in the movie and especially shake, flicker, blotches, lines and grain noise (these degradations are described below).

The restoration process

Several processes have been implemented and used to carry out the full restoration of the movie.

Digitalization The first step was the digitalization of the movie. The physical movie was scanned by telecine machine, put onto BestaSP and then captured to Abekas files.

Detection of the shotcuts. For easier manipulations, we decided to work on the shots of the movie. There is 38 shots of a few hundred mega bytes each.

Motion estimation/removal. To the viewer, the presence of shake is the most disconcerting example of movie degradation. Instead of steady camera motion, the picture appears to shake. There can be many reasons for this phenomenon. One is that the scanner or the digitizing device (téléciné) is not properly matched to the position of the film: scanned frames are displaced. Another is that the camera was held by hand.

The removal of the shake is performed by first estimating the global motion of the camera. An affine model was chosen to describe the displacement of the frames (translation, zoom and rotation). The affine model is needed since some frames are rotated. The estimation itself is performed through M-estimators. Then, the unwanted motion is compensated.

The estimation process takes around 3 seconds per frame on a PC and about 10 hours for the whole movie. The compensation itself is very fast.

Result: Shake Removal

Figure: Original shot
Figure: Deshaken shot
Figure: Deflickered shot
Figure: Deblotch shot
Figure: Final restoration
Page last modified on May 25, 2007