Proprietary file formats may not be supported long term by manufacturers and may vary from vendor to vendor. Many file formats use compression to force more data into less storage space and speed image precision, storage, and transmission. Without special software, computers generally cannot use the informational content of a raw image file to search for or retrieve a specific image. Search and retrieval normally depends on some form of indexing, which assigns specific metadata to each document, such as author, recipient, date, title, and content keywords. This index, or metadata, can be simple or sophisticated, and is typically an electronic database that is linked to the images.
Useful indexing requires careful planning and forethought before any actual imaging begins.
OCR is accomplished by a software application that reads the images and produces text based on recognized patterns in those images. Then, the electronic text can be stored in computer-readable form for search and retrieval purposes. Even when using good quality originals, there will be costs for post-scanning clean up of raw OCR text. The decision to adopt a document imaging system should be based on business needs. Agencies must justify the implementation of a system based on an analysis of their work processes and business needs balanced against costs.