Issue 6127051: code review 6127051: image/png: speed up PNG decoding for common color model...

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Issue 6127051: code review 6127051: image/png: speed up PNG decoding for common color model... (Closed)

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Created:
13 years, 6 months ago by nigeltao

Modified:
13 years, 6 months ago

Reviewers:

CC:
r, golang-dev

Visibility:
Public.

Description

image/png: speed up PNG decoding for common color models: Gray, NRGBA, Paletted, RGBA. benchmark old ns/op new ns/op delta BenchmarkDecodeGray 3681144 2536049 -31.11% BenchmarkDecodeNRGBAGradient 12108660 10020650 -17.24% BenchmarkDecodeNRGBAOpaque 10699230 8677165 -18.90% BenchmarkDecodePaletted 2562806 1458798 -43.08% BenchmarkDecodeRGB 8468175 7180730 -15.20% benchmark old MB/s new MB/s speedup BenchmarkDecodeGray 17.80 25.84 1.45x BenchmarkDecodeNRGBAGradient 21.65 26.16 1.21x BenchmarkDecodeNRGBAOpaque 24.50 30.21 1.23x BenchmarkDecodePaletted 25.57 44.92 1.76x BenchmarkDecodeRGB 30.96 36.51 1.18x $ file $GOROOT/src/pkg/image/png/testdata/bench* benchGray.png: PNG image, 256 x 256, 8-bit grayscale, non-interlaced benchNRGBA-gradient.png: PNG image, 256 x 256, 8-bit/color RGBA, non-interlaced benchNRGBA-opaque.png: PNG image, 256 x 256, 8-bit/color RGBA, non-interlaced benchPaletted.png: PNG image, 256 x 256, 8-bit colormap, non-interlaced benchRGB.png: PNG image, 256 x 256, 8-bit/color RGB, non-interlaced

	Unified diffs	Side-by-side diffs	Delta from patch set	Stats (+59 lines, -11 lines)			Patch
M	src/pkg/image/png/reader.go	View	1	3 chunks	+20 lines, -11 lines	0 comments	Download
M	src/pkg/image/png/reader_test.go	View	1	2 chunks	+39 lines, -0 lines	0 comments	Download
A	src/pkg/image/png/testdata/benchGray.png	View	1	Binary file		0 comments	Download
A	src/pkg/image/png/testdata/benchNRGBA-gradient.png	View	1	Binary file		0 comments	Download
A	src/pkg/image/png/testdata/benchNRGBA-opaque.png	View	1	Binary file		0 comments	Download
A	src/pkg/image/png/testdata/benchPaletted.png	View	1	Binary file		0 comments	Download
A	src/pkg/image/png/testdata/benchRGB.png	View	1	Binary file		0 comments	Download

Messages

Total messages: 3

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nigeltao

Hello r@golang.org (cc: golang-dev@googlegroups.com), I'd like you to review this change to https://go.googlecode.com/hg/

13 years, 6 months ago (2012-04-27 05:38:30 UTC) #1

nigeltao

13 years, 6 months ago (2012-04-27 06:04:12 UTC) #3

*** Submitted as http://code.google.com/p/go/source/detail?r=625e6c5be5ec ***

image/png: speed up PNG decoding for common color models: Gray, NRGBA,
Paletted, RGBA.

benchmark                       old ns/op    new ns/op    delta
BenchmarkDecodeGray               3681144      2536049  -31.11%
BenchmarkDecodeNRGBAGradient     12108660     10020650  -17.24%
BenchmarkDecodeNRGBAOpaque       10699230      8677165  -18.90%
BenchmarkDecodePaletted           2562806      1458798  -43.08%
BenchmarkDecodeRGB                8468175      7180730  -15.20%

benchmark                        old MB/s     new MB/s  speedup
BenchmarkDecodeGray                 17.80        25.84    1.45x
BenchmarkDecodeNRGBAGradient        21.65        26.16    1.21x
BenchmarkDecodeNRGBAOpaque          24.50        30.21    1.23x
BenchmarkDecodePaletted             25.57        44.92    1.76x
BenchmarkDecodeRGB                  30.96        36.51    1.18x

$ file $GOROOT/src/pkg/image/png/testdata/bench*
benchGray.png:           PNG image, 256 x 256, 8-bit grayscale, non-interlaced
benchNRGBA-gradient.png: PNG image, 256 x 256, 8-bit/color RGBA, non-interlaced
benchNRGBA-opaque.png:   PNG image, 256 x 256, 8-bit/color RGBA, non-interlaced
benchPaletted.png:       PNG image, 256 x 256, 8-bit colormap, non-interlaced
benchRGB.png:            PNG image, 256 x 256, 8-bit/color RGB, non-interlaced

R=r
CC=golang-dev
http://codereview.appspot.com/6127051

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