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
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 {};"
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
the VP8 decode functions do not need to be public; only
GetInfo/CheckSignature need to be marked extern as they're used by
libwebpmux.
Change-Id: Id9ab4d6166b0271cf5d04563c6dac1fcc84adbdc
- Match offsets, duration, width/height for frames/tiles and enforce
some constraints.
- Note that this also means using 'int's instead of 'uint32_t's for
16-bit and 24-bit fields.
Change-Id: If0b229ad9fce296372d961104aa36731a3b1304b
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
'Set' and 'Get' methods for images take/return a bitstream as input,
instead of separate 'image' and 'alpha' arguments.
Also,
- Make WebPDataCopy() a public API
- Use WebPData for storing data in WebPChunk.
- Fix a potential memleak.
Change-Id: I4bf5ee6b39971384cb124b5b43921c27e9aabf3e
- Move TAG_ID to webp/mux.h
- Rename it to WebPChunkId
- Rename IDs to WEBP_CHUNK_<tag>
- Remove "name" param from ChunkInfo struct and related changes.
- Rename WebPMuxNumNamedElements to WebPMuxNumChunks().
- WebPMuxNumChunks() takes WebPChunkId as param.
Change-Id: Ic6546e4a9ab823b556cdbc600faa137076546a2b
moves the implementation to ParseHeadersInternal. this also allows
decoding to start at a VP8X sub-chunk, e.g. 'ALPH'.
Change-Id: I06791f87d90f888de32746ecb02705e4b0ff227a
When importing BGRA or RGBA data for encoding, provide variants of
the WEBPImportPicture API for RGBX and BRGX data meaning the alpha
channel should be ignored.
Author: noel@chromium.org
from Chromium patch: https://chromiumcodereview.appspot.com/10496016/
Change-Id: I15fcaa4160c69a2b5549394204b6e6d7a1c5d333
VP8-lossy will now avoid writing an ALPH chunk if the
alpha values are trivial.
+ changed DumpPicture() accordingly in cwebp
+ prevented the -d option to be active with lossless
(DumpPicture wouldn't work).
Change-Id: I34fdb108a2b6207e93fa6cd00b1d2509a8e1dc4b
The new modes are
MODE_rgbA
MODE_bgrA
MODE_Argb
MODE_rgbA_4444
It's binary incompatible, since the enums changed.
While at it, i removed the now unneeded KeepAlpha methods.
-> Saved ~12k of code!
* made explicit mention that alpha_plane is persistent,
so we have access to the full alpha plane data at all time.
Incremental decoding of alpha was planned for, but not
implemented. So better not dragged this constaint for now
and make the code easier until we revisit that.
Change-Id: Idaba281a6ca819965ca062d1c23329f36d90c7ff
Change the lossless signature to 0x2f
Add 1 bit indicator for 'droppable (or trivial) alpha)'.
Add 3 bit lossless version (for future extension like yuv support).
Change the sub-resolution information to 3 bits implying range [2 .. 9]
Change-Id: Ic7b8c069240bbcd326cf5d5d4cd2dde8667851e2
- Make sure alpha flag is set in case of a lossless file with VP8X chunk.
The semantic of ALPHA_FLAG changes with this: it means the images
contain alpha (rather than ALPH chunk in particular).
- Update the mux container spec to add 1-line description of alpha
flag.
- Rename "HasLosslessImages()" to "MuxHasLosslessImages()", and other
similar function renames.
- Rename FeatureFlags to WebPFeatureFlags
- Elaborated a comment for a special case.
- A misc comment fix.
Change-Id: If212ccf4338c125b4c71c10bf281a51b3ba7ff45
- Separate out 'CHUNK_INDEX' from 'TAG_ID' (this is to help with the
situation where two different tags - "VP8 " and "VP8L" can have the
same TAG_ID -> IMAGE_ID).
- Some internal methods now take 'CHUNK_INDEX' param instea of 'TAG_ID'
as appropriate.
- Add kChunks[] entry for lossless.
- Rename WebPMuxImage.vp8_ --> WebPMuxImage.img_
- SetImage() and AddFrame/Tile() infer whether the bitstream is a
lossless one based on LOSSLESS_MAGIC_BYTE. The correct tag is stored
based on this.
Also, handle the case when GetVP8Info/GetVP8LInfo() fails.
Change-Id: I6b3bc9555cedb791b43f743b5a7770958864bb05
group like parameters together in prototypes, comments, move variable
declarations closer to first use.
Change-Id: Idd6bd87d0366d783fed83f4dd21bd7968cbe6948
- remove some unused functions
- move global arrays from data to read only section
- explicitly cast malloc returns; not specifically necessary, but helps
show intent
- miscellaneous formatting
Change-Id: Ib15fe5b37fe6c29c369ad928bdc3a7290cd13c84
These will report the 7x7-averaged PSNR or SSIM, using the
new internal function WebPPictureDistortion().
This is for information only. These flags have no encoding impact.
+misc opportunistic cosmetics
Change-Id: I64c0a7eca679134d39062e438886274b22bb643f
to 'clean up' the fully-transparent area and make it more compressible
new cwebp flags: -alpha_cleanup (off by default, since gain is not 100% guaranteed)
Change-Id: I74d77e1915eee146584cd61c9c1132a41db922eb
.. where only 2 filtering modes are potentially
tried, instead of all of them. This is fast than the exhaustive 'best'
mode, and not much worse.
Options for cwebp are:
-alpha_filter none
-alpha_filter fast (<- default)
-alpha_filter best (<- slow)
Change-Id: I8cb90ee11b8f981811e013ea4ad5bf72ba3ea7d4
Add predictive filtering option for Alpha plane.
Valid range for filter option is [0, 5] corresponding to prediction
methods none, horizontal, vertical, gradient & paeth filter.
The prediction method 5 will try all the prediction methods (0 to 4)
and pick the prediction method that gives best compression.
Change-Id: I9244d4a9c5017501a9696c7cec5045f04c16d49b
Extend WebP Encode functionality to encode Alpha data and produce
bit-stream (RIFF+VP8X+ALPH+VP8) corresponding to WebP-Alpha.
Change-Id: I983b4cd97be94a86a8e6d03b3b9c728db851bf48
