This option remaps internal parameters to better match
the expected compression curve of JPEG and produce output files
of similar size, but with better quality.
Change-Id: I96a1cbb480b1f6a0c6845a23c33dfd63f197b689
also change lossless encoder logic, which was relying on explicit
NULL return from WebPSafeMalloc(0)
renamed function to CheckSizeArgumentsOverflow() explicitly
addresses issue #138
Change-Id: Ibbd51cc0281e60e86dfd4c5496274399e4c0f7f3
* treat the last coeff as a special case
* re-arrange the inner code to be shorter
* replace some VP8EncBands[n] by n, for n = 0 or 1
Change-Id: I71e17b014cffad7b073e787fde06260905a6953f
- Separate out mux.h and demux.h
- muxtypes.h: new header for data types common to mux/demux
- Move some misc read/write utilities to utils/utils.h
- Remove some duplicate methods.
- Separate out mux/demux libraries
Change-Id: If9b9569b10d55d922ad9317ef51710544315d6de
10-15% faster encoding.
Almost same output, binary wise. The main difference is
that we can't compute uv_alpha susceptibility, means there
can be subtle differences with different -sns values.
Change-Id: Id1b1a50929bf125b6372212fee1ed75a3bed975f
Number of pairs selected are limited between 25% of histogram
images (at start) and number of histogram images left at any iteration.
Increase the range of iter_mult.
Removed min_cluster_size as parameter for tuning HistogramCombine.
Change-Id: Ia4068cd7af4d0f63c5af9001aceda8a40b9de740
* commit 'v0.2.1':
Update ChangeLog
update NEWS
bump version to 0.2.1
libwebp: validate chunk size in ParseOptionalChunks
cwebp (windows): fix alpha image import on XP
autoconf/libwebp: enable dll builds for mingw
[cd]webp: always output windows errors
fix double to float conversion warning
cwebp: fix jpg encodes on XP
VP8LAllocateHistogramSet: fix overflow in size calculation
GetHistoBits: fix integer overflow
EncodeImageInternal: fix uninitialized free
fix the -g/O3 discrepancy for 32bit compile
fix the BITS=8 case
Make *InitSSE2() functions be empty on non-SSE2 platform
make *InitSSE2() functions be empty on non-SSE2 platform
make VP8DspInitNEON() public
Conflicts:
src/Makefile.am
src/dsp/dec_neon.c
Change-Id: Iddc5152e4a6892db96c12d7c3f74adbc85fe6178
- Changed the dynamic range where more aggressive
(BackwardReferencesTraceBackward) heuristic is run from quality > 10
(instead of quality > 25).
- Limit the backward-ref Window size to 16*width & 256*width for lower
qualities ([0, 25[ & [25, 50[) respectively, instead of 1M window.
- Evaluate the params for HashChainFindCopy outside this function call
and pass it, instead of recomputing them for every call.
Change-Id: If9eedfc14b978e7632d7cf69c96186e2910b0554
the multiplications done for total_size would be done with integers,
possibly overflowing, before being promoted to 64-bit for the addition
Change-Id: I32c3a6400fc2ef120c38e01a8693f4cb1727234d
huff_image_size was a size_t (=32 bits with 32-bit builds) which could
rollover causing an incorrectly sized allocation and a crash in lossless
encoding.
fixes issue #128
Change-Id: I0f20cee98c29b2b40b02607930b6b7a7ca56996d
in debug mode, some float operations see their intermediate
values stored in memory rather than staying in the FPU (which
is 80bit precision).
Several fixes are possible (breaking long calculations into
atomic steps for instance), but simpler of all is just about
turning the cost[] array into float* instead of double*.
The code is a tad faster, and i didn't see any major output
size difference.
Change-Id: I053e6d340850f02761687e072b0782c6734d4bf8
LSIM stands for "local similarity": before matching
a compressed pixel to the source, we search around in the source
and minimise the squared error. So, this is close to PSNR calculation,
but mitigates some of its limitations (pure translation and noise for instance).
There's a new -print_lsim option to cwebp too.
Change-Id: Ia38561034c7a90e71d2ea0f55bb1de527eda245b
Make the heuristic for combining Histograms a function of compression
quality. This change will speed-up compression time for compression
quality less than 75. The compression time/density remains unchanged
for compression quality 75 and higher.
Change-Id: I94513d51078340fbc0737d459fab2cebdd2d6082
the multiplications done for total_size would be done with integers,
possibly overflowing, before being promoted to 64-bit for the addition
Change-Id: Id5c127c8a497ce5de89a276c17f36b59eeb67c21
huff_image_size was a size_t (=32 bits with 32-bit builds) which could
rollover causing an incorrectly sized allocation and a crash in lossless
encoding.
fixes issue #128
Change-Id: I175c8c6132ba9792034807c5c1028dfddfeb4ea5
in debug mode, some float operations see their intermediate
values stored in memory rather than staying in the FPU (which
is 80bit precision).
Several fixes are possible (breaking long calculations into
atomic steps for instance), but simpler of all is just about
turning the cost[] array into float* instead of double*.
The code is a tad faster, and i didn't see any major output
size difference.
Change-Id: Icf1f833e15f8ee4ecc7f9a521d07fdc96ef711aa
Returning 0 (equal) can lead to undefined behaviour.
And, in our cases we'll never have equal keys (added asserts for that)
Change-Id: Ifaf202df321d3f877ad2a03de42e0d6cdd1b2388
fixes the 'blocky sky problem' (saturation problem: when luma was flat,
chroma noise was taking over, resulting in random segment id assigned.
When just using a common uniform segment was better).
+ side clean-up and readibility/experimentability MACRO'ization
+ added '-map 7' option
Change-Id: I35982a9e43c0fecbfdd7b05e4813e8ba8c121d71
Added a threshold of MAX_COLORS_FOR_GRAPH for color-palettes, above
which the graph hint is ignored.
Change-Id: Ia5d7f45e52731b6eaf2806999d6be82861744fd3
spurious in this case, but addresses e.g.,
... potentially uninitialized local variable 'weighted_average' used
Change-Id: Ib99998bf49e4af7a82ee66f13fb850ca5b17dc71
Order-by-cost mostly unchanged (up to a scaling constant 1/log(2))
(except for few minor diff in < 2% of cases)
+ remove unused field cost_mode->cache_bits_
Change-Id: I714f8ab12f49a23f5d499a64c741382c9b489a3e
* ~1-4% faster
* if it's not used, don't use it
* remove the special handling of cache_bits = 0
* remove some tests in the loops
Change-Id: I19d87c3ca731052ff532ea8b2d8e89816507b75f
For low-color images, it may be better to not use color-palettes.
Users should treat this as one another hint (as with Photo &
Picture) and another parameter for tuning the compression density.
The optimum compression can still be obtained by running (outer loop)
compression with all possible tunable parameters.
Change-Id: Icb1a4face2a84774e16e801aee4a8ae97e232e8a
also relocate user_data from WebPAuxStats to the WebPPicture struct to
make clearing easier while placing it closer to the progress hook with
which it's used.
prior to this change some spurious lossless data could be reported in
the lossy (sans alpha) encoding case. additionally user_data could be
lost during lossless encoding.
Change-Id: I929fae3dfde4d445ff81bbaad51445ea586dd80b
* Extend AuxStats with new fields
it's slightly ABI-incompatible, but i guess it's ok for 0.1.99+
I expect to add more stats later, possibly (predictor stats, etc.)
* Have cwebp report the features used by lossless
compression (either for alpha or full lossless coding)
* Print the PSNR for alpha (useful in case of -alpha_q)
* clean-up alpha.c signatures
+ misc cleanup (added const '* const ptr', etc.)
Change-Id: I157a21581f1793cb0c6cc0882e7b0a2dde68a970
Evaluated the impact of this change over 1000 image corpus.
The compression density is up (on average) by 1.2% and encoding time has
gone down considerably from 716 ms (per file) to 146 ms (per file)
(4.9X improvement in encoding time).
Change-Id: Ida562cc0bfe18c9d6f5f00873c95f8396b480eab
Adds new methods WebPPictureARGBToYUVA() and WebPPictureYUVAToARGB()
Depending on the value of picture->use_argb_input,
the main call WebPEncode() will convert appropriately.
Note that both conversions are lossy, so it's recommended to:
* use YUVA input for lossy compression (picture->use_argb_input=0)
* use ARGB input for lossless compression (picture->use_argb_input=1)
Change-Id: I8269d607723ee8a1136b9f4999f7ff4e657bbb04
* add a real proper pointer for holding memory chunk pointer
(instead of using y and argb fields)
* polish the doc with details
* add a WebPPictureView() that extract a view from a picture
without any copy (kind of a fast-crop).
* properly snap the top-left corner for Crop/View. Previously,
the luma position was not snapped, and was off compared to the chroma.
Change-Id: I8a3620c7f5fc6f7d1f8dd89d9da167c91e237439
Adds a test of enc->mb_h_ to VP8IteratorProgress() to avoid a division
by zero. Fixes issue #121.
Original patch from even rouault (even dot rouault at gmail dot com).
Change-Id: Ie5fcc1821860c0a9366d5aa11f3aded4f5b98ed7
This limit corresponds to default histo_bits=3 for images upto sizes 400x400.
Any image higher than this dimension will bump up the histo_bits to 4 internally.
Change-Id: Ic8ba3dcd50e9c588cbbc4a0457289086498ff4ee
Fix inequality assertion on number of palette colors.
Fix inequality assertion test in BackwardReferencesHashChainFollowChosenPath.
Change-Id: Ie3242f1bbeaf96db91b839b6732ccce2634cebf3
