Permanent Pixels: Building Blocks for the Longevity of Digital Surrogates of Historical Photographs.René van Horik

The conversion of historical photographs, into digital surrogates facilitates the easy access to the intellectual content. Durable high quality digital master images available today enable the creation of specific derivatives in the future. As historical photographs often are very vulnerable and the conversion process is expensive, the creation of high quality digital master images is important. This paper presents three building blocks that can be used to realize a situation in which high quality digital surrogates of historical photographs are accessible and usable in the long run. The first building block for digital preservation is the application of a standardized image file format. This building block is based on the assumption that standards can be considered as durable. The second building block concerns the storage of the bit stream that makes up the digital surrogate in a durable data format. It is assumed that the XML data format as a non-proprietary data-encoding standard facilitates digital longevity. The third building block takes the creation of preservation metadata into consideration and is based on the assumption that metadata of digital objects is essential to understand and process the objects in the future.