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
Change-Id: I36d3765e94d2b5529b321c186ccee1744785c5b3
fixes:
error: ISO C++ forbids forward references to 'enum' types
since:
28d25c8 replace 'typedef struct {} X;" by "typedef struct X X; struct X {};"
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
SBITS=8 is reported 20-30% faster on ARM (where 64bit ops
are expensive).
Also use 32bits for i32.
Change-Id: Id6a7197d805061aeb8832f20432512d0d930ebfa
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
this will avoid the "dec_neon.o has no symbol" warning
no change in binary size observed on linux.
Change-Id: Ia27ae2bc5a03d714afa7e46671fdcf4cb630784d
lossy was rounding with a bias toward opaque:
[232+, 8] -> [15, 1]
now both paths use the range:
[240+, 16] -> [15, 1]
Change-Id: I3da2063b4959b9e9f45bae09e640acc1f43470c5
With this, MODE_rgbA can safely be used without speed penalty
even in case of pure-lossy alpha-less input.
It's also an optimization when cropping a fully-opaque region from
an image with alpha: premultiply is then skipped
Change-Id: Ibee28c75744f193dacdfccd5a2e7cd1e44604db6
* green was not descaled properly
* alpha was over-dithered, making the value '0x0f' not be a fixed point
* alpha value was not restored ok.
Change-Id: Ia4a4d75bdad41257f7c07ef76a487065ac36fede
Fix the lossless decoder for the case when it has to apply other
inverse transforms before applying Color indexing inverse transform.
The main idea is to make ColorIndexingInverse virtually in-place: we
use the fact that the argb_cache is allocated to accommodate all
*unpacked* pixels of a macro-row, not just *packed* pixels.
Change-Id: I27f11f3043f863dfd753cc2580bc5b36376800c4
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
no speed diff observed by removing the test before calling BitWriterResize().
+ remove some unnecessary memset() in VP8LBitWriter
+ fix mixed code/variable-decl in BIG_ENDIAN mode
Change-Id: I36be61f83d10a43e4682b680c2dae0e494da4218
* ~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
* commit 'v0.1.99': (39 commits)
Update ChangeLog
add extra precision about default values and behaviour
header/doc clean up
Makefile.vc: fix webpmux.exe *-dynamic builds
remove INAM, ICOP, ... chunks from the test webp file.
harmonize authors as "Name (mail@address)"
makefile.unix: provide examples/webpmux target
update NEWS
README: cosmetics
man/cwebp.1: wording, change the date
add a very crude progress report for lossless
rename 'use_argb_input' to 'use_argb'
add some padding bytes areas for later use
fixing the findings by Frederic Kayser to the bitstream spec
add missing ABI compatibility checks
Doc: container spec text tweaks
add ABI compatibility check
mux.h: remove '* const' from function parameters
encode.h: remove '* const' from function parameters
decode.h: remove '* const' from function parameters
...
Conflicts:
src/mux/muxinternal.c
Change-Id: I635d095c451742e878088464fe6232637a331511
Put emphasis on RGBA decoding instead of RGB/BGR
Clarify doc at some rough spots
Misc typo fix and cosmetics
Change-Id: Ic5fcfcc5bf4d612c5de23b0a5499f1fadde55bfe
- WEBP_MUX_INVALID_PARAMETER: was used only at one place, and that too
should actually be an assert().
- WEBP_MUX_ERROR: was never used.
Change-Id: I8883cb4dfae7a7918507501f21fced0c04dda36a
minor revision shouldn't matter, we only check major revision number.
Bumped all version numbers so that incompatibility starts *now*
Change-Id: Id06c20f03039845ae4cfb3fd121807b931d67ee4
