This report documents the jpylyzer tool, which is a validator and properties extractor for JPEG 2000 Part 1 (JP2) images. The software was developed as part of the SCAPE Work Package PC.WP.QA (Quality Assurance Components). Amongst other things, this work package addresses improved quality assurance for automated digitisation and imaging workflows. The JP2 format (which is part of the JPEG 2000 image compression standard) is getting increasingly popular for storing digitised content, both for access and preservation.
Jpylyzer was designed to cover the following two aspects of quality assurance in JPEG 2000 imaging workflows:
- Validation against the JP2 format specifications, which ensures that images are standards compliant. It is also effective for detecting common forms of byte-level corruption.
- Validation of image and encoding properties against an institute-specific profile. Jpylyzer doesn’t perform this second type of validation by itself, but its extracted properties can be validated against an external schema that defines the institute-specific profile.
Although other tools exist for these tasks, their ‘validation’ scope is rather limited, which introduces the risk that malformed and badly damaged images will go unnoticed. In addition, quite a few tools exist for extracting properties for this format, but most of these either focus on the JP2 header fields or on the codestream headers. Jpylyzer was designed with the aim of filling these gaps.
Johan van der Knijff
KB/ National Library of the Netherlands