garyttierney
commented
1 year ago I've created a branch here that uses the JNR wrapper by Johannes Baiter: https://github.com/dbmdz/imageio-jnr.
Some initial comments/thoughts:
- Grok has diverged too far from OpenJpeg to use this same wrapper for both decoders. We'd need to maintain 2 slightly different wrappers.
- Streaming works end-to-end with JP2s now, in addition, the full color bitmap copy is avoided -- reducing disk thrashing and memory usage when dealing with images that have components smaller than RGBA32.
- There is a work in progress to move all current Cantaloupe
Processors into the ImageIO codec system. I've done this for imageio-openjpeg but there's likely a larger piece of work to get everything lined up as expected by the maintainer.- Related to above, metadata now comes from the ImageIO plugin instead of the reader itself. This could regress or expose new properties to the API, needs testing.
Observations:
- Micro-benchmarks are noticeably faster when processing a JP2 stream
- Byte range requests are never cached, even when desirable
At the moment, Cantaloupe's performance is poor with OpenJPEG or Grok processors because it needs to copy files before accessing streams. This also means it can't make byte-range requests to S3 with those processors.
It does work fine with Kakadu though - so can we make it work the same way for OpenJPEG and Grok and therefore support byte-range S3 requests without Kakadu?
Spike to investigate.