Mosaic "The Last Judgement"

 
 

The Golden Gate - the southern entrance to the cathedral of St. Vitus - is decorated with a unique work of art, a coloured, richly gilded mosaic representing the Last Judgement. In 1992 the Office of the President of the Czech Republic and the Getty Conservation Institute began to cooperate to restore and conserve the mosaic ( more information about mosaic and the restoration project).

 
 

Having the historical photo of the mosaic from the end of the 19th century and the photos of the current state, we study the evolution of the mosaic, which was several times reconstructed and conserved. Firstly we tried to restaurate the historical photograph - remove noise, deblur the image, incearse the contrast. Then, we remove the geometrical difference between images (by means of the image registration). Finally, we identify mutual differences between the photos, which indicate the changes realized on the mosaic during the centuries.

 
 

On the following image you can see the "similarity" function between the photos. By means of the mutual information method we tried to improve the localization of the feature points, which were selected manually. The B point was selected manually, the A point was chosen as the best corresponding one to the P point by the automatic method. The A position is the correct one.


 

 
 

  We detected several differences between the images. For example see following Figure and compare the corresponding regions. The region No.1: The hair wave, wich is present on the current mosaic, is missing on the old one. The region No.2: The top coffin edge on the historical image continues till the border. The region No.3: The ornamental patterns have different shapes on the photographs.

 
 

The final research report can be downloaded here (38MB ZIPPED PS file)