ARHIVSKI VJESNIK 41. (ZAGREB, 1998.)

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B. Justrell, Digital imaging in archives, Arh. vjesn., god. 41 (1998), str. 23-28 Digital images are also known as "raster" or "bit mapped" images, and they are different from other types of electronic files, for example vector files, in which graphic information is represented as mathematically defined lines and curves. Digital images are, unlike alphanumeric text files, "dump" files because the information in them cannot be searched. Advantages and disadvantages of digital imaging Digital images offer many advantages over analogue counterparts like photocopy and microfilm in terms of capture, duplication, storage and transmission. The technology has the potential to create a higher quality reproduction of a deteriorating original then conventional copying processes. This technology is also very flexible. A page may be inserted or replaced with ease, and a digital image can, unlike microfilm or photocopies, be reproduced over and over again and all subsequent copies of that digital image will retain the same quality. Unlike microfilm and paper, digital images do not decay with use, and they offer several alternatives in output - paper, microfilm, digital files - for distribution to users. Digital images can also be transferred over networks for remote, simultaneous and multiple access. But - as mentioned above - there are a number of drawbacks that, at least currently, limit the utility of digital imaging in archival management. Besides the problems of obsolescence and that special recopying, storage and migration requirements must be considered when planning for a digital imaging system, there are legal constraints, including copyright, lack of standards and wide variations in quality and capacity of hardware and software. Like other recently introduced technologies digital imaging also suffers from a frustrating lack of vendor support and stability. All these disadvantages can - or will be possible in the future - to overcome. However, many micrographie and imaging experts are arguing for a so called "hybrid system" approach which means using the best out of two technologies: microfilm for preservation and digital images for access. Today a growing number of archival institutions are initiating digital imaging programmes: National Archives of Canada are digitizing its collection of photo negatives on nitrate film, Archivo de Indias in Seville in Spain has up until today digitized more than 11 million pages from records of the Spanish colonisation of America, State Library in New South Wales in Australia has digitized about 8 000 pages of manuscripts from the Joseph Banks collection and they are now available on the Internet - just to mention some archival initiatives. The important thing with these programmes is that they have to be carefully defined to guarantee success and minimize failure. Before starting such a programme realistic expectations have to be set up, built on an understanding of the attributes of the documents which are to be converted but also of the conditions for digital capture and of the whole range of uses the digital images will support. 25