Part II: Digital Imaging (Week 2)

This week's reading consisted of the second half of Howard Besser's Introduction to Imaging released from the Getty Institute online. This half stressed the importance of careful planning of all aspects before undertaking a project in digitizing a collection. Improper planning could result in a disorganized project and running out of funds before the project is even completed. One of the most important pieces in the planning stage is confirming the legal status of the object being scanned. It is vital to know if legal clearances are required to " reproduce the originals or to modify and display the reproductions"-- also check that we have those clearances if they are necessary. Severe repercussions could come from illegally reproducing and display the digital reproduction.

There are several other points made throughout the second half of Besser's writing and research. Some of them are:

1. Scanning is either done in-house or contracted out. If done in-house, there are four different types of scanners that can be used: drum, flatbed, film or transparency and a digital camera set on a copy stand. Drums scanners offer the highest quality scan (up to 8,000 samples per inch, spi) but that material scanned must be flexible and durable. Mounted or fragile objects could not be scanned. A flatbed scanners can scan between 1200 and 5000 spi, and are very affordable, but can only scan the object so long as it fits within the glass. A film or transparency scanner can scan negatives or slides and are are comparable quality to flatbed scanners. For the fragile or over-sized objects, the digital camera on a copy stand is the best choice. Digital cameras also allow control over the lighting conditions and can document 3-D objects.
2. Before image capture, it is important to decide exactly what has to be digitized and what wouldn't be important. Highly fragile objects should only be copied if it is necessary. Black and white negatives can last over 200 years in the right conditions and color negatives over 50--better copies can be made from them than from a digital copy of them. It would be better to avoid digitizing them. Be sure that the scanning parameters are also set. Besser recommends to "use-neutral" which means the master files are created of high quality so they can be used for any future purpose. Scan at the highest spi the scanner allows for.
3. There are several metadata schemas available for use. Some of them are: MARC (Machine-Readable Cataloging), EAS (Encoded Archival Description), CDWA (Categories for the Description of Works of Art), and MPEG-7 (Multimedia Content Description Interface). MARC has long been used to create bibliographic records. EAS is a set of rules "for creating finding aids for archival collections" in which, there is a specified intellectual and physical arrangement of the collection as a whole. CDWA is used to describe artworks and their visual "surrogates." MPEG-7 is used to describe multimedia and audiovisual works and is growing in importance.
4. XML is a code that is used to describe data unlike the better known HTML, which is used merely to present data. XML can make semantic parts (like "author" or "title") machine-readable, meaning they can be understood and "acted upon" by computer programs. XML also gives users uniformly created metadata packages that can easily be shared, migrated, published to the Web--in other words, XML is extremely versatile.
5. In quality control, checksums should be documented and periodically compared. Checksums are the exact number of bits in a specific file, or actual values and pattern of data using slightly more complex checksum algorithms.
6. When testing access to digital collections via the internet, be sure to check how the site looks when opened with various browsers as well as both Macintosh and PCs. That way, the site can be made to look uniform on all of them.
7. Digital Preservation is an important concern as hardware obsolescence is constantly occurring and files need to be saved on new hardware or as different types of files so new programs can read them. It is also important to run periodic checks on a digital collection to be sure that files have not corrupted over time and that they still open properly. It important that vigilance is taken with watching data conditions and technological trends to manage the collection accordingly.
8. Be sure to make multiple copies of the assets stored on different formats and then at different geographic locations in case of fire, water damage or other atmospheric inferences. If one is destroyed there are other copies saved in other locations.
9. Migration is the updating of files by resaving them in new formats so that new software can read them. This is problematic because transforming data can cause corruption or loss of information. This could destroy the digital copy completely. Technology Preservation is one suggestion to solve this problem, by which the institution would preserve the technological conditions in order to keep the older formats from becoming obsolete and needing updates.
   
10. Emulation is a tool used for "digital archeology" or the method and processes to recover data from obsolete hardware, defunct format or corrupted files if preservation strategies fail. It has been used to recreate arcade games by using software that gives the "look and feel" of the original, but without the original hardware.
    

The problem with digital collections and born-digital images is that there is no best preservation method developed and no one is sure of what strategies would be correct at this point. It is important to afford the most protection to Master Files and to keep up with technological trends and to manage the digital collection with care and diligence. The need for digital collections is growing as the amount of born-digital images and media are being created. They also give a wider access to the world's cultural heritage than ever before, which opens possibilities for learning, sharing and gaining an appreciation for photographs and other cultural objects.