Fork of openjpeg library for JPEG2000 encoding and decoding https://git.carlh.net/cgit/openjpeg/atom?h=cancel 2025-01-24T12:26:40Z 2025-01-24T12:26:40Z Carl Hetherington cth@carlh.net 2025-01-24T12:26:40Z urn:sha1:e53debb0a1b49af365cd9b67b7161d343c872ecd 2020-05-20T18:31:28Z Even Rouault even.rouault@spatialys.com 2020-05-20T16:00:45Z urn:sha1:3cd1305596f191a01afdc11f9355f9c6590065dd The previous constant opj_c13318 was mysteriously equal to 2/K , and in the DWT, we had to divide K and opj_c13318 by 2... The issue was that the band->stepsize computation in tcd.c didn't take into account the log2gain of the band. The effect of this change is expected to be mostly equivalent to the previous situation, except some difference in rounding. But it leads to a dramatic reduction of the mean square error and peak error in the irreversible encoding of issue141.tif ! 2020-05-20T18:30:21Z Even Rouault even.rouault@spatialys.com 2020-04-30T09:52:42Z urn:sha1:07d1f775a1ef95496b0c78b18f671dac41983320 Update the bench_dwt utility to have a -decode/-encode switch Measured performance gains for DWT encoder on a Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz (4 cores, hyper threaded) Encoding time: $ ./bin/bench_dwt -encode -num_threads 1 time for dwt_encode: total = 8.348 s, wallclock = 8.352 s $ ./bin/bench_dwt -encode -num_threads 2 time for dwt_encode: total = 9.776 s, wallclock = 4.904 s $ ./bin/bench_dwt -encode -num_threads 4 time for dwt_encode: total = 13.188 s, wallclock = 3.310 s $ ./bin/bench_dwt -encode -num_threads 8 time for dwt_encode: total = 30.024 s, wallclock = 4.064 s Scaling is probably limited by memory access patterns causing memory access to be the bottleneck. The slightly worse results with threads==8 than with thread==4 is due to hyperthreading being not appropriate here. 2017-09-01T14:30:29Z Even Rouault even.rouault@spatialys.com 2017-09-01T14:30:29Z urn:sha1:f9e9942330f476b66ac4a35d0ae521200878f343 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. 2017-08-20T20:02:41Z Even Rouault even.rouault@spatialys.com 2017-08-20T20:02:41Z urn:sha1:f87c5ef7ebef3d7a908e98f2de1b6a0336ae57ae 2017-08-18T13:08:51Z Even Rouault even.rouault@spatialys.com 2017-08-18T13:08:51Z urn:sha1:5d403250561398f7ba3041d9eb8c893bd680dd72 This lowers 'bin/opj_decompress -i ../MAPA.jp2 -o out.tif -d 0,0,256,256' down to 0.860s 2017-07-30T17:46:52Z Even Rouault even.rouault@spatialys.com 2017-07-30T17:46:52Z urn:sha1:13cde9fa37249628af6b6f10601b733f87a025f4 2017-05-15T10:21:30Z Even Rouault even.rouault@spatialys.com 2017-05-15T10:21:30Z urn:sha1:3c2972f924857016bb454201c7e92f25de9105ee 2016-09-08T08:30:09Z Even Rouault even.rouault@spatialys.com 2016-09-08T08:30:09Z urn:sha1:48c16b2c199210a3c20b306a737eac5fc2c8f6c9 Conflicts: src/lib/openjp2/t1.c 2016-09-05T22:49:53Z Matthieu Darbois mayeut@users.noreply.github.com 2016-09-05T22:49:53Z urn:sha1:9f24b078c7193e886f6cfb329d3469eb1facf68d Visual Studio 2015 does not pass regression tests with `__restrict` so kept disabled for MSVC. Need to check proper usage of OPJ_RESTRICT (if correct then there’s probably a bug in vc14) Closes #661