Optimising archival JP2s for the derivation of access copies
Like many other organisations that are using JPEG 2000, the KB produces two representations of most of its digitised content (newspapers, books, periodicals):
- a high-quality, losslessly compressed JP2 that is the archival master;
- a lesser-quality, lossily compressed JP2 that is used as an access image (this is used for e.g. our newspapers website).
The majority of our digitisation work is contracted out to external suppliers, and both master and access images are typically derived from from a parent (TIFF) image, which is converted to JP2 using the settings for master and access images, respectively. This means that we’re not currently using the archival masters for producing derived images. However, there may be a need for this at some point in the future. For instance, we may need higher quality access images, or access images that give better performance in our access environment. Because of this, I was asked to take a further look into ways to derive access JP2s directly from our archival masters.
In this blog post I’ll be sharing some preliminary findings of this work, which may be of interest to other JPEG 2000 practitioners as well. All images and test results that I’ll be showing along the way are available from this Github repository, so you can have a go at these data yourself, if you’re so inclined.
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JP2
- Generating lossy access JP2s from lossless preservation masters
- Jpylyzer 2015 round-up
- Response to report on JPEG 2000 expert round table
- Six ways to decode a lossy JP2
- Jpylyzer software finalist voor digitale duurzaamheidsprijs
- Optimising archival JP2s for the derivation of access copies
- ICC profiles and resolution in JP2: update on 2011 D-Lib paper
- Automated assessment of JP2 against a technical profile
- Update on jpylyzer
- Jpylyzer documentation
- A prototype JP2 validator and properties extractor
- A simple JP2 file structure checker
- Paper on JPEG 2000 for preservation
- Ensuring the suitability of JPEG 2000 for preservation
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jpeg-2000
- Generating lossy access JP2s from lossless preservation masters
- Jpylyzer 2015 round-up
- Response to report on JPEG 2000 expert round table
- Six ways to decode a lossy JP2
- Jpylyzer software finalist voor digitale duurzaamheidsprijs
- Optimising archival JP2s for the derivation of access copies
- ICC profiles and resolution in JP2: update on 2011 D-Lib paper
- Automated assessment of JP2 against a technical profile
- Update on jpylyzer
- Jpylyzer documentation
- A prototype JP2 validator and properties extractor
- A simple JP2 file structure checker
- Paper on JPEG 2000 for preservation
- Ensuring the suitability of JPEG 2000 for preservation
