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JPEG2000

Saturday,  06/21/03  12:12 PM

I'm back!  I know I've been neglecting you; more travel, and much work to do...

I've been deep in the intricacies of JPEG2000 codecs, rather arcane but for Aperio rather critical.  It turns out that - like virtually all specs - the JPEG2000 spec is not 100% specified, there is enough wiggle room for different implementations to be, well, different; and the differences result in incompatibilities as well as perceptible differences in image quality.  Aperio's ScanScope has superior image quality to any other slide imaging solution, and so naturally we are anxious to have the best possible compression technology.

As well, different implementations have different performance characteristics.  JPEG2000 is highly asymmetric, which is a good thing; this means compression is much more CPU-intensive and takes much longer than decompression.  That said, we still want compression to be as fast as possible.  We have big images (like 10GB!) and they take minutes rather than seconds to compress, and the faster the better.  Some codecs have really good image quality but are so slow as to be unusable in actual practice.

The best solution for compression performance is hardware acceleration, and here again there are differences; some codecs are optimized for single-threaded performance, while others are designed explicitly for the parallel processing possible with hardware.  I want a codec which has terrific image quality, is compatible with all other implementations, runs fast in a software-only implementation, and is optimized for implementation in hardware.  Is that too much to ask?