Guetzli検証(その4) - 高解像度画像編

画像処理 PC

　これまでに行ったGuetzli検証ではシステムリソース(主にメインメモリ)の制約から、長辺をHD或いはFullHD相当の1280pxや1920pxにリサイズした画像を入力画像としてテストしてきました。
　今回はメモリが潤沢なマシンで1000万画素オーバーの高解像度画像で検証を行います。画質の定性的な評価については、(リサイズした)同一画像で既に評価しているため、本投稿ではパフォーマンスについてのみ記述します。
　

前提条件

OS
Windows 10 Home (64bit)
CPU
Core i7 i7 2640M (2.8GHz / Max. 3.50GHz) 2core 4threads
Memory
16GB

　テストデータは従来同様、Cloud, Plum, ST, TTの4パターンを利用しました。
　

Test Data: Cloud

空と雲

Input File Spec
Resolution
4200x3154 (13MP)
Bit Depth
8bit
Color Space
sRGB
File Format
PNG (internally ZIP compression)

　

Result
Quality OutputSize [Bytes] CompressionRatio ProcessingTime [sec]
guetzli_84 587864 5.06% 559.22
guetzli_85 607545 5.23% 553.36
guetzli_86 675884 5.82% 656.71
guetzli_87 710357 6.12% 685.41
guetzli_88 798715 6.88% 739.68
guetzli_89 878125 7.57% 739.55
guetzli_90 1129875 9.73% 789.33
guetzli_91 1330056 11.46% 949.65
guetzli_92 1524651 13.14% 994.05
guetzli_93 1812779 15.62% 1167.31
guetzli_94 2219980 19.13% 1501.36
guetzli_95 2663815 22.95% 2010.75
guetzli_96 3308127 28.50% 2105.35
guetzli_97 4366050 37.62% 2999.44
guetzli_98 6187912 53.31% 7176.15
guetzli_99 8707070 75.01% 5016.58
guetzli_100 8995710 77.50% 1130.25
libjpeg_10 94835 0.82% 0.51
libjpeg_20 119170 1.03% 0.5
libjpeg_30 148793 1.28% 0.53
libjpeg_40 180822 1.56% 0.49
libjpeg_50 219531 1.89% 0.52
libjpeg_60 269627 2.32% 0.52
libjpeg_70 372514 3.21% 0.48
libjpeg_80 578667 4.99% 0.56
libjpeg_84 752334 6.48% 0.49
libjpeg_85 786427 6.78% 0.53
libjpeg_86 866805 7.47% 0.49
libjpeg_87 906314 7.81% 0.53
libjpeg_88 1000703 8.62% 0.58
libjpeg_89 1059379 9.13% 0.6
libjpeg_90 1432064 12.34% 0.68
libjpeg_91 1562177 13.46% 0.59
libjpeg_92 1656719 14.27% 0.67
libjpeg_93 1904061 16.40% 0.68
libjpeg_94 2207576 19.02% 0.72
libjpeg_95 2525258 21.76% 0.72
libjpeg_96 3055761 26.33% 0.89
libjpeg_97 3622729 31.21% 0.82
libjpeg_98 4352021 37.49% 0.71
libjpeg_99 6148832 52.97% 1.02
libjpeg_100 8655600 74.57% 1

f:id:kachine:20170323192709p:plain
　

Test Data: Plum

梅の花

Input File Spec
Resolution
4200x3154 (13MP)
Bit Depth
8bit
Color Space
sRGB
File Format
PNG (internally ZIP compression)

　

Result
Quality OutputSize [Bytes] CompressionRatio ProcessingTime [sec]
guetzli_84 1305861 7.91% 948.11
guetzli_85 1344411 8.14% 970.31
guetzli_86 1445240 8.76% 1004.53
guetzli_87 1502739 9.10% 964.33
guetzli_88 1668014 10.11% 1137.79
guetzli_89 1823497 11.05% 1083
guetzli_90 1954383 11.84% 1110.83
guetzli_91 2123706 12.87% 1046.28
guetzli_92 2353731 14.26% 1164.21
guetzli_93 2824811 17.11% 1309.64
guetzli_94 3378410 20.47% 1518.59
guetzli_95 3782880 22.92% 1549.13
guetzli_96 4299223 26.05% 1864.53
guetzli_97 4970448 30.11% 2188.35
guetzli_98 5864231 35.53% 2595.59
guetzli_99 8155324 49.41% 8100.38
guetzli_100 10859539 65.79% 1557.3
libjpeg_10 116159 0.70% 0.53
libjpeg_20 161129 0.98% 0.54
libjpeg_30 221250 1.34% 0.56
libjpeg_40 307713 1.86% 0.5
libjpeg_50 422979 2.56% 0.46
libjpeg_60 563607 3.41% 0.5
libjpeg_70 807797 4.89% 0.55
libjpeg_80 1198619 7.26% 0.51
libjpeg_84 1476764 8.95% 0.56
libjpeg_85 1543217 9.35% 0.53
libjpeg_86 1663179 10.08% 0.5
libjpeg_87 1731945 10.49% 0.58
libjpeg_88 1874323 11.36% 0.54
libjpeg_89 1979085 11.99% 0.59
libjpeg_90 2409782 14.60% 0.61
libjpeg_91 2601384 15.76% 0.64
libjpeg_92 2762102 16.73% 0.61
libjpeg_93 3080995 18.67% 0.61
libjpeg_94 3507446 21.25% 0.8
libjpeg_95 3960932 24.00% 0.64
libjpeg_96 4675816 28.33% 0.75
libjpeg_97 5413617 32.80% 0.76
libjpeg_98 6302926 38.19% 0.81
libjpeg_99 8107410 49.12% 0.78
libjpeg_100 10564541 64.00% 0.91

f:id:kachine:20170323192728p:plain
　

Test Data: ST

東京スカイツリーと東武スカイツリーライン

Input File Spec
Resolution
3150x4200 (13MP)
Bit Depth
8bit
Color Space
sRGB
File Format
PNG (internally ZIP compression)

　

Result
Quality OutputSize [Bytes] CompressionRatio ProcessingTime [sec]
guetzli_84 1175866 8.23% 776.72
guetzli_85 1224590 8.57% 861.78
guetzli_86 1421080 9.94% 865.23
guetzli_87 1518566 10.63% 978.99
guetzli_88 1736835 12.15% 1229.21
guetzli_89 1905401 13.33% 1254.39
guetzli_90 2134511 14.93% 1517.62
guetzli_91 2402302 16.81% 1877.89
guetzli_92 2687240 18.80% 1957.44
guetzli_93 3114681 21.79% 2157.83
guetzli_94 3727121 26.08% 2790.53
guetzli_95 4281523 29.96% 3480.41
guetzli_96 9411457 65.85% 4845.06
guetzli_97 5953178 41.65% 7116.35
guetzli_98 6837326 47.84% 6858.89
guetzli_99 9411457 65.85% 5947.07
guetzli_100 9411457 65.85% 1715.46
libjpeg_10 203217 1.42% 0.68
libjpeg_20 319739 2.24% 0.57
libjpeg_30 412163 2.88% 0.5
libjpeg_40 484487 3.39% 0.5
libjpeg_50 556082 3.89% 0.5
libjpeg_60 634362 4.44% 0.47
libjpeg_70 765486 5.36% 0.5
libjpeg_80 1023883 7.16% 0.53
libjpeg_84 1242022 8.69% 0.59
libjpeg_85 1283592 8.98% 0.58
libjpeg_86 1372593 9.60% 0.59
libjpeg_87 1428068 9.99% 0.59
libjpeg_88 1539035 10.77% 0.5
libjpeg_89 1612436 11.28% 0.52
libjpeg_90 2065832 14.45% 0.64
libjpeg_91 2214255 15.49% 0.69
libjpeg_92 2331368 16.31% 0.72
libjpeg_93 2607794 18.25% 0.62
libjpeg_94 2911780 20.37% 0.72
libjpeg_95 3275093 22.92% 0.66
libjpeg_96 3841023 26.88% 0.7
libjpeg_97 4475709 31.32% 0.78
libjpeg_98 5251352 36.74% 0.75
libjpeg_99 6915589 48.39% 0.87
libjpeg_100 9089273 63.60% 0.97

f:id:kachine:20170323192854p:plain
　

Test Data: TT

東京タワーと赤羽橋交差点

Input File Spec
Resolution
4200x2800 (12MP)
Bit Depth
8bit
Color Space
sRGB
File Format
PNG (internally ZIP compression)

　

Result
Quality OutputSize [Bytes] CompressionRatio ProcessingTime [sec]
guetzli_84 1261178 9.25% 732.66
guetzli_85 1294867 9.49% 737.15
guetzli_86 1369680 10.04% 791.6
guetzli_87 1420259 10.41% 776.55
guetzli_88 1558636 11.43% 781.76
guetzli_89 1701961 12.48% 876.39
guetzli_90 1860519 13.64% 1061.31
guetzli_91 2218999 16.27% 1116.23
guetzli_92 2430456 17.82% 1108.86
guetzli_93 2782210 20.40% 1330.35
guetzli_94 3231048 23.69% 1637.89
guetzli_95 3606213 26.44% 1909.37
guetzli_96 4151757 30.44% 1942.95
guetzli_97 9883331 72.47% 2312.35
guetzli_98 6041819 44.30% 4096.77
guetzli_99 9883331 72.47% 5020.01
guetzli_100 9883331 72.47% 1980.51
libjpeg_10 190777 1.40% 0.6
libjpeg_20 303622 2.23% 0.52
libjpeg_30 394956 2.90% 0.58
libjpeg_40 474136 3.48% 0.59
libjpeg_50 559823 4.10% 0.58
libjpeg_60 664257 4.87% 0.58
libjpeg_70 849040 6.23% 0.47
libjpeg_80 1164494 8.54% 0.58
libjpeg_84 1399977 10.27% 0.63
libjpeg_85 1448813 10.62% 0.59
libjpeg_86 1545299 11.33% 0.58
libjpeg_87 1603906 11.76% 0.69
libjpeg_88 1720168 12.61% 0.61
libjpeg_89 1800449 13.20% 0.54
libjpeg_90 2365397 17.34% 0.7
libjpeg_91 2528992 18.54% 0.72
libjpeg_92 2662584 19.52% 0.66
libjpeg_93 2946289 21.60% 0.8
libjpeg_94 3270923 23.98% 0.72
libjpeg_95 3658800 26.83% 0.67
libjpeg_96 4249574 31.16% 0.73
libjpeg_97 4904589 35.96% 0.7
libjpeg_98 5695461 41.76% 0.8
libjpeg_99 7335839 53.79% 0.81
libjpeg_100 9564985 70.14% 0.89

f:id:kachine:20170323192904p:plain
　

まとめ

　最も遅いパターンでは2時間以上かかってます。動画エンコードではなく静止画のエンコードなのに。それでいて、出力ファイルサイズが有意に小さいわけでもなければ、目視しても有意に高画質だとも思いません。
　これまでの検証結果も踏まえ、解像度、画像内容いずれのパターンでもGuetzliは使いどころのないJPEGエンコーダだと判断せざるをえなさそうです。
　



以上。