Commit Graph

3 Commits

Author SHA1 Message Date
Even Rouault b2cc8f7f81 Optimize reading/write into sparse array 2017-09-01 16:30:50 +02:00
Even Rouault d1299d9670 Fix compiler warning in release mode 2017-09-01 16:30:39 +02:00
Even Rouault f9e9942330 Sub-tile decoding: only allocate tile component buffer of the needed dimension
Instead of being the full tile size.

* Use a sparse array mechanism to store code-blocks and intermediate stages of
  IDWT.
* IDWT, DC level shift and MCT stages are done just on that smaller array.
* Improve copy of tile component array to final image, by saving an intermediate
  buffer.
* For full-tile decoding at reduced resolution, only allocate the tile buffer to
  the reduced size, instead of the full-resolution size.
2017-09-01 16:30:29 +02:00