Optical storage of page images and pictorial data - opportunities and needed advances in information retrieval

We describe two current development projects at the Library of Congress using high-density optical storage, both of which require more advanced and improved computer-based information retrieval methodologies than existing bibliographic retrieval systems. A much greater emphasis will be placed on the information content of the articles rather than on the broad subject categories in general use for computer retrieval citations to book materials. Needed approaches include the linking of selected external reference sources and the extraction of character-encoded index information from the page images by OCR techniques. Our position is that extremely high density storage of articles in a single subject area requires a finer resolution in the retrieval system accessing the material. A single side of a 12-inch digital optical disk, for example, can hold 15 years of the Journal of the ACM.