Overall looking for accuracy (adherence to technical specs), completeness and consistency. A general practice is for the person conducting the quality review not to be the same person who performed the actual scanning as this helps to have a fresh set of eyes when reviewing details. Another approach is to wait a reasonable period between scanning work and QC review.
File format is Tiff
Resolution is set at min. of 300 ppi
Scanned at 24 bit depth
AdobeRGB1998 color profile1 2
Validate that all pages are turned to their proper orientation
Scanned the entire page with edges (a uniform border should be visible around entire page - use black background paper)
Scanned dimensions closely match actual size of the original and consistent size across all pages in the digital object
Scanned the complete document including blank pages, reverse side of pages, front and back matter, hard covers, spine, etc.
the only exception would be newsclippings which are almost always photocopied and blank on the back.
Ensure that no cropping of page text has occurred
Visually check that no distortion or blemishes obscure the legibility due to photo processing (i.e. that a blemish is not part of the original text and or any glare from protective covering is minimized)
Confirm page sequence matches original and filenames have been properly applied (eg wrcXXXXX_XXX)
Perform visual comparison of digitized images with original document, checking for any missing or mislabeled pages
(optional for Flat Bed scanning) Open a random page from each object in Photoshop, and visually confirm overall tone and color matches original. Should confirm image is in focus by viewing at a resolution view of 50-100%
Examples:
(1) Note on color management - use AdobeRGB1998 color profile ( since using flat bed scanner and monitor calibration may not be feasible. Recommend using a standard ICC to maintain consistent color throughout images )
Benchmark for Faithful Digital Reproductions of Monographs and Serials. Digital Library Federation. Version 1. (December 2002) http://old.diglib.org/standards/bmarkfin.htm (download PDF)
Minimum Digitization Capture Recommendations (Draft). Association for Library Collections and Technical Services Preservation and Reformatting Section (2012) http://connect.ala.org/node/185648
Digital Records: Digitised Image Specification. UK National Archives. (4 April 2011) http://www.nationalarchives.gov.uk/documents/information-management/digitisation-image-specification.pdf (see page 11+ for specs for other source documents -- e.g. transparencies)
A Framework of Guidance for Building Good Digital Collections. URL: http://framework.niso.org
Digital Imaging Tutorial - Quality Control Cornell Library
Quality Assurance - Image Defects. Stanford University Libraries
https://lib.stanford.edu/digital-production-services/quality-assurance-image-defects
Quality in HathiTrust. (See sections: Types of Problems and Outlook for Correction and Appendix: Error Examples.)
https://www.hathitrust.org/quality-in-hathitrust
Local scanning examples