<title>Evaluation of digital image quality requirements for illustrations of the Smithsonian Institution</title>

Abstract

While museums and archiving institutions are under pressure to make their document collections accessible to an increasing number of scientific researchers and other users, optimal preservation of paper-based documents requires storage in temperature and humidity conditions that preclude easy access and frequent handling. Very high quality digital imaging is seen by many museums as a means of providing document users simultaneous access to reproductions of close-to-original quality. However, there are few guidelines published concerning image quality. To develop a preliminary set of quality and compression standards, the Smithsonian's National Museum of Natural History requested that we examine, in detail, one of its collections of documents, namely its Fish Illustration Collection. Our aim was to develop specifications providing a level of detail that would satisfy demanding researchers and curators, yet not result in excessive storage and/or transmission time. Our examinations included visual analyses, spot metering with a digital colorimeter, and digital scanning at various sampling frequencies and levels of quantization of the originals and several types of photographic reproductions The Museum's researchers and curators found that reproductions produced according to our specifications using carefully calibrated, high quality document scanners and computer monitors are very faithful to the originals.