7 Commits

Author	SHA1	Message	Date
Nigel Tao	07fcf9c2fe	vp8: skip filtering for all-zero-DC macroblock residuals. ... This makes the Go code match the libwebp C code's output on blue-purple-pink-large.*-filter.lossy.webp Also make the various WEBP benchmarks all decode a similar image, the image at http://blog.golang.org/gophercon/image01.jpg, to make it more meaningful to e.g. compare the simple filter's numbers with the normal filter's numbers. Also fix a "go vet" warning in webp/decode.go. The test data was generated by: wget http://blog.golang.org/gophercon/image01.jpg -O blue-purple-pink-large.jpeg convert blue-purple-pink-large.jpeg blue-purple-pink-large.png cwebp -lossless blue-purple-pink-large.png -o blue-purple-pink-large.lossless.webp cwebp -q 80 -f 0 blue-purple-pink-large.png -o blue-purple-pink-large.no-filter.lossy.webp cwebp -q 80 -strong blue-purple-pink-large.png -o blue-purple-pink-large.normal-filter.lossy.webp cwebp -q 80 -nostrong blue-purple-pink-large.png -o blue-purple-pink-large.simple-filter.lossy.webp dwebp -pgm blue-purple-pink-large.no-filter.lossy.webp -o tmp.pgm && convert tmp.pgm blue-purple-pink-large.no-filter.lossy.webp.ycbcr.png && rm tmp.pgm dwebp -pgm blue-purple-pink-large.normal-filter.lossy.webp -o tmp.pgm && convert tmp.pgm blue-purple-pink-large.normal-filter.lossy.webp.ycbcr.png && rm tmp.pgm dwebp -pgm blue-purple-pink-large.simple-filter.lossy.webp -o tmp.pgm && convert tmp.pgm blue-purple-pink-large.simple-filter.lossy.webp.ycbcr.png && rm tmp.pgm LGTM=r R=r CC=golang-codereviews https://golang.org/cl/106230044	2014-06-30 10:36:25 +10:00
Rui Ueyama	dc115882f1	go.image/vp8: use branch-free abs ... This change seems to restore performance to the level before CL 108140045. benchmark old ns/op new ns/op delta BenchmarkDecodeVP8SimpleFilter 796416 784394 -1.51% BenchmarkDecodeVP8NormalFilter 4931138 4693078 -4.83% BenchmarkDecodeVP8L 7820030 7821796 +0.02% LGTM=nigeltao, r R=nigeltao, r CC=golang-codereviews https://golang.org/cl/107340047	2014-06-30 10:33:37 +10:00
Nigel Tao	f8a86727c2	go.image/vp8: remove the filter look-up tables. ... The benchmarks are a little slower, but the code is shorter. benchmark old ns/op new ns/op delta BenchmarkDecodeVP8SimpleFilter 621950 644184 +3.57% BenchmarkDecodeVP8NormalFilter 4045745 4269431 +5.53% LGTM=r R=r, minux, ruiu CC=golang-codereviews https://golang.org/cl/108140045	2014-06-27 09:14:15 +10:00
Nigel Tao	0424e74a0e	go.image/vp8: implement the normal filter. ... The testdata was generated via: cwebp foo.png -o foo.lossy.webp dwebp -pgm foo.lossy.webp -o tmp.pgm convert tmp.pgm foo.lossy.webp.ycbcr.png rm tmp.pgm TBR=r R=r CC=golang-codereviews https://golang.org/cl/107330043	2014-06-26 13:29:30 +10:00
Nigel Tao	94ba43c478	go.image/vp8l: new package. ... The blue-purple-pink image comes from http://blog.golang.org/gophercon The tux and yellow_rose images come from https://developers.google.com/speed/webp/gallery2 and according to that page, those images are in the public domain. The gopher-doc images are http://golang.org/doc/gopher/doc.png after quantizing its palette to 2/4/16/256 colors. LGTM=r R=r CC=golang-codereviews https://golang.org/cl/109010043	2014-06-17 21:51:57 +10:00
Nigel Tao	72be9c51b1	go.image/vp8: implement the loop filter. ... The testdata files were created by: cwebp video-001.png -o video-001.webp dwebp -pgm video-001.webp -o tmp.pgm convert tmp.pgm video-001.webp.ycbcr.png rm tmp.pgm LGTM=r R=r CC=chaishushan, golang-codereviews https://golang.org/cl/91700044	2014-05-27 10:52:02 +10:00
Nigel Tao	f93749e6f2	go.image/vp8, go.image/webp: new packages, copied from ... code.google.com/p/vp8-go This is a straight copy, followed by import path updates. LGTM=r R=r, mirtchovski, oleku.konko CC=golang-codereviews https://golang.org/cl/79320043	2014-03-25 13:29:48 +11:00