Quality assurance

Digitizing: Quality assurance

Rapidly changing technologies - including user access methods, scanning equipment, delivery media, and new file formats - present a challenge to the timely creation of scanning standards.

OCLC Preservation Service Centers address quality assurance issues through a process that checks and rechecks the quality, legibility, and accuracy of the scan file. We develop a quality reference test, or benchmarking test, to verify the proper functioning of scanning equipment, and carefully check the original source, as well as the scan, at each step of the process.

For further quality assurance, microfilm reels intended for scanning are evaluated for factors affecting scanner setup. Since OCLC Preservation Service Centers have a full duplication laboratory, new duplicate negatives can be made if different film types and/or densities will improve the quality of the scanned image.

Before scanning, microfilm is examined on a microfilm reader to record pagination anomalies, filming errors, and condition of the original material. Scanned images are then fully inspected to ensure bibliographic integrity by comparing the resulting images to the microfilm record.

Each image is inspected on a screen at one-to-one resolution to ensure legibility relative to the original. Files are deleted, cropped, or rotated as necessary. Rescanning is performed for some files to improve image quality.

The directory structure is created according to client specifications, and files are checked for proper naming and directory placement. Custom programs are also used to verify some file-naming schemes.

Media is then recorded from our imaging server and verified for completeness and readability.

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