Scanning Specifications

OCLC Preservation Services performed the scanning work following detailed instructions provided in the NLM Statement of Work for "Digitization of Print and Microfilm Collections." Hard copy originals of pamphlets were scanned in 8-bit grayscale and 24-bit color (covers and color foldouts) using a Betterlight 8000 digital camera and low-UV emission North Light lights. Emphasis was placed on careful handling of the pamphlets following NLM guidelines. A custom-built glass overlay was designed for the project to enable the camera operator to control page movement during image capture in a non-damaging way. Microfilmed versions of some pamphlets were digitized in 8-bit grayscale using a NextScan Eclipse scanner primarily to test the feasibility of scanning from film. Output includes TIFF masters (with NLM-specified metadata in headers), OCR, and PDF and JPEG derivative files, as well as technical and structural metadata in METS (Metadata Encoding Transmission Standard) wrappers with ALTO page layout metadata.