We compact the palette by weighted distance, favoring the green channel.
Average gain on paletted file is ~0.5%, with gain up to 6-7% on some favorable cases.
Encoding speed is unaffected.
Disabled for alpha (or any single-channel input)
Also: always use quality=20 for EncodePalette() since it
doesn't make any real difference.
Change-Id: I19fb14316a366f139a941b45aef5663a33c905e1
SSE2 version is 2.1x faster
This is used to transfer the alpha plane to green channel before lossless compression.
Change-Id: I01d9df0051c183b1ff5d6eb69961d4f43e33141a
Don't combine the Histograms that have trivial (single valued A, R & B)
symbols.
Following is the compression savings data along with compression time (before
& after) per image.
Before After
bpp, rate(MP/s) bpp, rate(MP/s)
Q=25, method = 4 2.508, 1.807 2.499, 1.916
Q=50, method = 4 2.460, 1.488 2.456, 1.512
Q=75, method = 4 2.452, 1.078 2.450, 1.092
Q=25, method = 5 2.505, 1.398 2.496, 1.383
Q=50, method = 5 2.458, 1.170 2.453, 1.143
Q=75, method = 5 2.453, 0.886 2.450, 0.855
This change provides 0.1-0.4% compression gains and speeds up the lossless
compression for the default method=4 (the drop in compression speed is between 1-3.5% for method=5).
Change-Id: Idfd88c2092f37afacd26a97097b3053f8183953a
Tested on 1000 pngs corpus with quality 90-100 it gives ~0.15% improvement
in compression density and ~7% speed up.
Change-Id: I460f56c96707edb3c1f0b51a024e5122e10458df
if ALPHA_LOSSLESS_COMPRESSION produces a too big file (very rare!),
we fall-back to no-compression automatically.
Change-Id: I5f3f509c635ce43a5e7c23f5d0f0c8329a5f24b7
rightmost pixel was missing a copy, which could lead to invalid read.
Also added a lower dimension of 4, below which we use the regular conversion.
This is to prevent corner cases, in addition to not being overkill.
Change-Id: Iac12e7a3d74590f12fe8eeb1830b9891e61439f6
with a special case for dithering==0., it gets somewhat faster on x86
thanks to inlining.
Also, less macros.
Change-Id: Ic2f2bf6718310743bb40cef2104fa759a073e6d5
New function: WebPPictureSmartARGBToYUVA()
This implement smart RGB->YUV conversion.
This is rather undocumented for now, and is triggered using '-pre 4'
preprocessing option.
This is slow-ish and use quite some memory, but should be improvable.
This is somehow a usable beta version.
Change-Id: Ia50a8c30134e4cab8a7d3eb70aef13ce1f6187a1
This compresses the uimage using lossless compression and controlable
decimating pre-process.
Code is under WEBP_EXPERIMENTAL_FEATURE while it's being experimented with.
Change-Id: I8b7f4cfcc3c6afc52a556102842bdbb045ed5ee8
(typecast uint32 pointer to uint64).
The proposed change is little (0.05%) slower but avoids uint32 to uint64
pointer conversion.
Change-Id: I6b8828077ea1324fabd04bfa7e7439e324776250
Sometimes, the error-code was not set correctly.
We now return OUT_OF_MEMORY everytimes it's appropriate
(tested using MALLOC_FAIL_AT mechanism)
Took the opportunity to clean-up the code and dust the error
code returned (some were erroneously set to INVALID_CONFIGURATION)
Change-Id: I56f7331e2447557b3dd038e245daace4fc82214c
only 1 of <lib>_CPPFLAGS and AM_CPPFLAGS is used, with the former
getting precedence when it's defined. configure's DEFAULT_INCLUDES is
covering what's necessary given the include paths are all source
relative.
Change-Id: I7d14076acd266b28a88a3d92bcc3d7165284d5f3
this change has the side-effect of using directory names in the
include, silencing a lint warning.
Change-Id: Ib91cf63a90534e32fadfa5c2372bfdb29f854d02
if res->first = 1, coeffs[0]=0 because of quant.c:749 and line
added at quant.c:744
So, no need for the extra case.
Going forward, TrellisQuantizeBlock() should also be calling
a variant of VP8SetResidualCoeffs() to set the 'last' field.
also: fixes a warning for win64
+ slight speed-up
Change-Id: Ib24b611f7396d24aeb5b56dc74d5c39160f048f0
The luminance needs to be pre- and post- multiplied by
the alpha value in case of rescaling, for proper averaging.
Also:
- removed util/alpha_processing and moved it to dsp/
- removed WebPInitPremultiply() which was mostly useless
and merged it with the new function WebPInitAlphaProcessing()
Change-Id: If089cefd4ec53f6880a791c476fb1c7f7c5a8e60
