This document describes the preservation plan for image content in the McMaster University Digital Archive. The preservation plan for image content follows from policies and practices described in the Strategic Framework for Digital Preservation and the Digital Preservation Implementation Plan. This document explains practical steps that McMaster University Library takes to preserve the intellectual content of image in digital format. It outlines the basic tools, methods, and standards used for the long-term preservation of image content.
For the preservation of image content, McMaster University Library requires uncompressed TIF versions of the content, and descriptive metadata. During the ingest process, derivatives are created for display and easy access. McMaster University Library continuously monitors developments in file formats to determine if and when formats require migration (see Environmental Monitoring of Preservation Formats).
Image SIPs (see Definition of SIP) generally consist of a TIF file, and an associated MODS descriptive metadata file.
Analysis on Ingest
Upon ingest, every file in the repository is subject to identification of its file format and validation using FITS. The output of the FITS identification and validation processes are recorded to a technical metadata datastream (TECHMD_FITS) that is associated with the object in the repository.
McMaster University Library does not ingest files that are not referenced (either as part of a representation or as associated datastreams) in the associated metadata. As the SIP is retained, these files can later be ingested if necessary.
There is no format normalization if the submitted object is a TIF.
When necessary, McMaster University Library crosswalks descriptive metadata from MODS to Dublin Core. The repository creates preservation metadata for each file. The preservation level, explained in the Digital Preservation Implementation Plan, is applied to each file upon ingest and recorded in the preservation metadata for each file.
For the Full Preservation level for image, currently the acceptable formats are TIF. Image submissions may also be JPG or PNG format, however they will be preserved at the Bit-level Preservation level.