In this work we consider some of the problems related to the restoration of digital images reconstructed in color from triple black and white negatives taken by S.M. Prokudin-Gorsky. In 1905-1916 S.M. Prokudin-Gorsky (1863-1944), an early 20th century Russian photographer and researcher, has created "The Collection of the Splendours of Russia in Natural Colours" - the unique set of colour photographs of the Russian Empire on the eve of the October Revolu-tion of 1917.

However these images are scanned from the material which is over 100 years old and the original glass plates usually contain defects of different kind.

We strongly advocate the "non-retouching" policy for the "first line" archival set of registered color images. If this principle is observed this set of digital reconstructions will contain defects which, in most cases, are inherited from one of the three frames of triple black and white negatives. The question which we start to investigate in this work is whether the properties of triple color material does in principle allow for the production of the "second line" set of partially corrected digital reconstructions which will have some of these defects removed on the basis of information contained in two other frames of the image. More precisely we address the following research tasks.

(1) Describe the class of defects which can be automatically identified in the registered color image and develop reliability criteria for the detection process.

(2) Analyze and describe the subclass of such defects which can be reliably corrected without adding arbitrary changes to the image that cannot be justified by information containing in the original triple black and white material.

This page contains partial results related to both issues.