Blogs

Six ways to decode a lossy JP2

Some time ago Will Palmer, Peter May and Peter Cliff of the British Library published a really interesting paper that investigated three different JPEG 2000 codecs, and their effects on image quality in response to lossy compression. Most remarkably, their analysis revealed differences not only in the way these codecs encode (compress) an image, but also in the decoding phase. In other words: reading the same lossy JP2 produced different results depending on which implementation was used to decode it.

A limitation of the paper's methodology is that it obscures the individual effects of the encoding and decoding components, since both are essentially lumped in the analysis. Thus, it's not clear how much of the observed degradation in image quality is caused by the compression, and how much by the decoding. This made me wonder how similar the decode results of different codecs really are.

SCAPE Project Ends on the 30th of September

It is difficult to write that headline. After nearly four years of hard work, worry, setbacks, triumphs, weariness, and exultation, the SCAPE project is finally coming to an end.

I am convinced that I will look back at this period as one of the highlights of my career. I hope that many of my SCAPE colleagues will feel the same way.

I believe SCAPE was an outstanding example of a successful European project, characterised by

Weirder than old: The CP/M File System and Legacy Disk Extracts for New Zealand’s Department of Conservation

We’ve been doing legacy disk extracts at Archives New Zealand for a number of years with much of the effort enabling us to do this work being done by colleague Mick Crouch, and former Archives New Zealand colleague Euan Cochrane – earlier this year, we received some disks from New Zealand’s Department of Conservation (DoC) which we successfully imaged and extracted what was needed by the department. While it was a pretty straightforward exercise, there was enough about it that was cool enough to warrant that this blog be an opportunity to document another facet of the digital preservation work we’re doing, especially in the spirit of being another war story that other’s in the community can refer to. We do conclude with a few thoughts about where we still relied on a little luck, and we’ll have to keep that in mind moving forward.