Image virtual restoration



(Italiano / English)
 

One of the major problems of a library is to guarantee the conservation of the rare library material which is in danger of deterioration (in particular, manuscripts and autographs) and, at the same time, to allow its consultation to users.

The most common solution is to substitue the original document with a microfilm; experience shows, however, a lack of stability with a consequent lack of information.

Computerised technology through image scanning permits to overcome the typical limits of microfilm processing and to acquire new important functionalities.The project "Image virtual restoration"being implemented at the National Central Library of Florence is structured in four phases:

1. HIGH QUALITY IMAGE SCANNING
It permits the acquisition of maximum information about the document (also information not visible to the naked eye) without causing damages to it.

2. IMAGE VIRTUAL RESTORATION
The image which is acquired in the digital phase is the exact reproduction of the original, with regard to the state of the document and the included information. By using an ad hoc software it is possible to proceed to a virtual restoration: the image of the original document is computer processed until it produces a new image of the perfectly restored document. This technique, which doed not entail any intervention on the original, permits to optimise the readability of the textual or artistic message of the document, no matter its making technique, its carrier and conservation stage.
Whereas the metology of "real restoration" aims at consolidating the present status of the documentand at preventing it from possible alteration in order to mantain a high level of the information contained in the original, "virtual restoration" is done on the image and not on the phisical document. It enables the reader to capture information which is not possible to obtain from the current document.
The metodology of "virtual restoration" allows many performances which is impossble to implement in "real" restoration: colour cleansing, retrieving marks which have been erased or covered, enhancing weak signs, reading informations which is not perfectly visible. By enabling information retrieve impossible to obtain through ordinary techniques, virtual restoration intervenes where traditional restoration cannot succeed: therefore, it cannot be seen as opposed to real restoration, but as a technique which integrates it ,an helping aid for textual reading and historical and philological research.

3. CREATION OF HIGH DEFINITION CD-ROMs
Virtual restoration eventually leads to the creation of CD-ROMs with electronic versions of the processed documents. Image archives are therefore made available to the user, without making any harm to the original. High quality images are mastered on CD-ROMs and substitute the old archives of filmed images. These CD-ROMs can also be used for quality publishing of facsimile.

4. CREATION OF LOW DEFINITION CD-ROM
A second modality of use, which is different from the previous both for quality and aim, consists of creating CD-ROMs with low quality compressed images, which are made available to the user for quick consultation and Internet browsing.