11 Commits

Author SHA1 Message Date
Urvang Joshi
47374b8273 Alpha unfilter for given set of rows
Support reconstruction of small number of rows at a time.

Change-Id: Ief1bc78c7ad011ec6df856551f3beb5f907fd8e0
2013-06-11 15:57:42 -07:00
James Zern
d640614d54 update copyright text
rather than symlink the webm/vpx terms, use the same header as libvpx to
reference in-tree files

based on the discussion in:
https://codereview.chromium.org/12771026/

Change-Id: Ia3067ecddefaa7ee01550136e00f7b3f086d4af4
2013-06-06 23:09:14 -07:00
Vikas Arora
8eae188a62 WebP-Lossless encoding improvements.
Lossy (with Alpha) image compression gets 2.3X speedup.
Compressing lossless images is 20%-40% faster now.

Change-Id: I41f0225838b48ae5c60b1effd1b0de72fecb3ae6
2013-05-08 17:22:11 -07:00
skal
0aef3ebdea make alpha unfilter work in-place
* remove a malloc
* remove the unused 'bpp' argument from filter/unfilter functions

Change-Id: I28d78baaaddc20f1d5a3bb2bd0b4e96a12a920d8
2013-03-15 01:36:38 +01:00
James Zern
fbd82b5a39 types.h: centralize use of stddef.h
for size_t / NULL

Change-Id: If1331d3cf44296ed0ba9e838eae2f5b1bcaeb61b
2012-04-12 17:14:58 -07:00
James Zern
a0b2736d79 cosmetics & warnings
- 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
2012-01-30 17:19:53 -08:00
Pascal Massimino
57cab7b891 Harmonize the alpha-filter predictions at boundary
often reduces compressed size by ~10's of bytes
+ refactored / sped-up the prediction code (gradient: ~30% faster)

Change-Id: I26bd983655dad4f85d5c5ddc20a1980f384c4dd6
2012-01-10 03:21:13 -08:00
Pascal Massimino
8ca2076de1 Introduce a 'fast' alpha mode
.. 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
2012-01-09 02:37:44 -08:00
James Zern
ad1e163a0d cosmetics: normalize copyright headers
Change-Id: I5e2462b101e0447a4f15a1455c07131bc97a52dd
2012-01-06 14:49:06 -08:00
James Zern
9d0e17c9a9 fix msvc build breakage after 252028a
replace inline with WEBP_INLINE; inline is reserved for c++ code
w/visual studio

Change-Id: Ib06c6a12fd786701740d8b260d9aa310ee81fddf
2012-01-05 18:26:40 -08:00
Vikas Arora
252028aaac Add predictive filtering option for Alpha.
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
2012-01-05 13:55:35 +05:30