Upgrade to Pro — share decks privately, control downloads, hide ads and more …
Sign up for free

Using ImageMagick to resize your Images [WebPer...

Sponsored · SiteGround - Reliable hosting with speed, security, and support you can count on. →
Avatar for newtron newtron
March 18, 2015
Technology
850
2

Using ImageMagick to resize your Images [WebPerfTO]

Toronto Web Performance Group,
2015-03-17
https://github.com/nwtn/pres-imagemagick-webperfto

Avatar for newtron

newtron

March 18, 2015

More Decks by newtron

See All by newtron
Universal web design [Accessibility Camp Toronto]
Avatar for newtron newtron
0
260
Universal web design [HackerYou a11y club]
Avatar for newtron newtron
0
240
Universal web design [Full Stack Toronto]
Avatar for newtron newtron
0
290
Information architecture as knowledge translation [World IA Day]
Avatar for newtron newtron
0
320
Improving performance with responsive (and responsible!) images [CSSDay.io]
Avatar for newtron newtron
1
420
Universal Web Design: How to create an awesome experience for every user [Open Source Bridge]
Avatar for newtron newtron
0
310
Improving performance with responsive (and responsible!) images [CSSConf]
Avatar for newtron newtron
6
760
Universal Web Design: How to create an awesome experience for every user [OpenWest]
Avatar for newtron newtron
0
330
Improving performance with responsive (and responsible!) images [OpenWest]
Avatar for newtron newtron
2
410

Other Decks in Technology

See All in Technology
公共システムAdventCalendar2026
Avatar for Toru_Kubota toru_kubota
0
280
AI AgentによるEmbedded SREの取り組み
Avatar for norimichi.osanai tgidgd
1
360
2026 Apache Flink Community Checkpoint
Avatar for Robert Metzger rmetzger
0
200
Building Audio Plugin Ecosystem for Android in 2026
Avatar for Atsushi Eno atsushieno
2
160
Lint の層を組み直した話
Avatar for 弁護士ドットコム bengo4com
3
320
AI時代に求められる優秀なTechLeadの振る舞い
Avatar for pospome pospome
11
15k
自律的なチームを作るためにTechPMがやらないこと
Avatar for Naoki Yoshitake ny7760
1
530
AWS構成から考えるWebセキュリティ ― WordPressの構築経験から考える公開範囲と更新運用【JAWS FESTA 2026 in AKITA】
Avatar for サイバーセキュリティクラウド cscengineer
PRO
2
350
Content Mapper APIの応用例～CSS Modules、言語ファイル～
Avatar for uhyo uhyo
2
620
なぜ東京にいる私が、新潟の技術コミュニティを運営するのか by 八雲慎之助
Avatar for やくも yakumo
0
220
【dbts2026】AIエージェントの 判断と探索を変える、 データベース エンジニアリング― 既存DBの処理と依存関係から作る、オペレーショナルオントロジー ―
Avatar for KoheiOgawa shisyu_gaku
0
240
HQ駆動開発で最高のAI-Contextを作ろう
Avatar for SansanTech sansantech
PRO
1
110

Featured

See All Featured
Build The Right Thing And Hit Your Dates
Avatar for Maggie C. maggiecrowley
39
3.5k
Improving Core Web Vitals using Speculation Rules API
Avatar for Sergey Chernyshev sergeychernyshev
21
1.7k
The agentic SEO stack - context over prompts
Avatar for schlessera schlessera
0
1k
Designing for Performance
Avatar for Lara Hogan lara
612
70k
Bash Introduction
Avatar for André Augusto Costa Santos 62gerente
615
220k
Evolving SEO for Evolving Search Engines
Avatar for Ryan Jones ryanjones
0
360
Connecting the Dots Between Site Speed, User Experience & Your Business [WebExpo 2025]
Avatar for Tammy Everts tammyeverts
11
1.1k
The Illustrated Guide to Node.js - THAT Conference 2024
Avatar for David Neal reverentgeek
1
600
Product Roadmaps are Hard
Avatar for C. Todd Lombardo iamctodd
55
13k
Evolution of real-time – Irina Nazarova, EuRuKo, 2024
Avatar for Irina Nazarova irinanazarova
9
1.7k
Sam Torres - BigQuery for SEOs
Avatar for Tech SEO Connect techseoconnect
PRO
0
610
Navigating the Design Leadership Dip - Product Design Week Design Leaders+ Conference 2024
Avatar for Andy Polaine apolaine
2
510

Transcript

  1. David Newton, St. Michael’s Hospital 1 1 Using ImageMagick to

    resize your Images Toronto Web Performance Group, 2015-03-17 Twitter: @newtron Github: @nwtn Email: [email protected] Slides + image credits: https://github.com/nwtn/pres-imagemagick-webperfto

  2. 2

  3. 3 Responsive images are a pain in the butt

  4. 4

  5. 5

  6. 6

  7. 7 ImageMagick, y’all

  8. 8

  9. 9 $ brew install imagemagick

  10. 10 Condition File size: mean File size: % difference Photoshop

    CC, with optimization 260,304.70 KB ImageMagick `-resize` 337,665.98 KB 52.39%

  11. 11 How does image resizing work?

  12. 12 685,936 pixels 189,739 pixels

  13. 13 …to 64 pixels? How do we get from 16

    pixels…

  14. 14 != resampling

  15. 15 …to 64 pixels? How do we get from 16

    pixels…

  16. 16 …to 64 pixels? How do we get from 16

    pixels… Background interpolation

  17. 17 …to 64 pixels? How do we get from 16

    pixels… Nearest-neighbour interpolation

  18. 18 Nearest-neighbour interpolation

  19. 19 Bicubic interpolation

  20. 20 Nearest-neighbour vs. bicubic interpolation

  21. 21 7 colours 1,146 colours

  22. 22

  23. More colours = More bytes* 23

  24. 24 https://github.com/nwtn/image-resize-tests/

  25. 25 How do we know which options are best?

  26. Quality objective: measured with DSSIM 26

  27. 27 Control Test Difference

  28. 28

  29. Quality subjective: from me 29

  30. Test a variety of images 30

  31. 31 The best* settings for ImageMagick

  32. 32 mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2.0 -thumbnail OUTPUT_WIDTH

    -unsharp 0.25x0.08+8.3+0.045 -dither None - posterize 136 -quality 82 -define png:preserve-colormap=true - interlace none INPUT_PATH With optimization:

  33. 33 https://imageoptim.com/

  34. 34 mogrify -path OUTPUT_PATH -filter Triangle - define filter:support=2.0 -thumbnail

    OUTPUT_WIDTH -unsharp 0.25x0.25+8.00+0.065 - dither None -posterize 136 -background Black - alpha Background -quality 82 -define jpeg:fancy- upsampling=off -define png:compression-filter=5 -define png:compression-level=9 -define png:compression-strategy=1 -define png:exclude- chunk=all -interlace none -colorspace sRGB - strip INPUT_PATH Without optimization:

  35. 35 mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2.0 -thumbnail OUTPUT_WIDTH

    -unsharp 0.25x0.08+8.3+0.045 -dither None - posterize 136 -quality 82 -define png:preserve-colormap=true - interlace none INPUT_PATH

  36. 36 mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2.0 -thumbnail OUTPUT_WIDTH

    -unsharp 0.25x0.08+8.3+0.045 -dither None - posterize 136 -quality 82 -define png:preserve-colormap=true - interlace none INPUT_PATH

  37. 37 Adaptive resize Distort resize Geometry Interpolative resize Liquid rescale

    Resize Sample Scale Thumbnail

  38. 38 mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2.0 -thumbnail OUTPUT_WIDTH

    -unsharp 0.25x0.08+8.3+0.045 -dither None - posterize 136 -quality 82 -define png:preserve-colormap=true - interlace none INPUT_PATH

  39. 39 (x1 ,y2 ) (x2 ,y2 ) (x1 ,y1 )

    (x2 ,y1 ) (x,y) = + + +

  40. 40 mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2.0 -thumbnail OUTPUT_WIDTH

    -unsharp 0.25x0.08+8.3+0.045 -dither None - posterize 136 -quality 82 -define png:preserve-colormap=true - interlace none INPUT_PATH

  41. 41

  42. 42 mogrify -path OUTPUT_PATH -filter Triangle - define filter:support=2.0 -thumbnail

    OUTPUT_WIDTH -unsharp 0.25x0.25+8.00+0.065 - dither None -posterize 136 -background Black - alpha Background -quality 82 -define jpeg:fancy- upsampling=off -define png:compression-filter=5 -define png:compression-level=9 -define png:compression-strategy=1 -define png:exclude- chunk=all -interlace none -colorspace sRGB - strip INPUT_PATH

  43. 43 Fancy

  44. 43 Fancy

  45. 44 mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2.0 -thumbnail OUTPUT_WIDTH

    -unsharp 0.25x0.08+8.3+0.045 -dither None - posterize 136 -quality 82 -define png:preserve-colormap=true - interlace none INPUT_PATH

  46. 45 -unsharp 0.25x0.08+8.3+0.045 radius sigma gain threshold

  47. 46 -unsharp 0.25x0.08+8.3+0.045 radius sigma gain threshold

  48. 47 mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2.0 -thumbnail OUTPUT_WIDTH

    -unsharp 0.25x0.08+8.3+0.045 -dither None - posterize 136 -quality 82 -define png:preserve-colormap=true - interlace none INPUT_PATH

  49. 48

  50. 49

  51. 50

  52. 51

  53. 52 mogrify -path OUTPUT_PATH -filter Triangle - define filter:support=2.0 -thumbnail

    OUTPUT_WIDTH -unsharp 0.25x0.25+8.00+0.065 - dither None -posterize 136 -background Black - alpha Background -quality 82 -define jpeg:fancy- upsampling=off -define png:compression-filter=5 -define png:compression-level=9 -define png:compression-strategy=1 -define png:exclude- chunk=all -interlace none -colorspace sRGB - strip INPUT_PATH

  54. 53

  55. More colours = More bytes* 54

  56. 55

  57. 56 mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2.0 -thumbnail OUTPUT_WIDTH

    -unsharp 0.25x0.08+8.3+0.045 -dither None - posterize 136 -quality 82 -define png:preserve-colormap=true - interlace none INPUT_PATH

  58. 57 quality 10 quality 40 quality 70 quality 100

  59. 58 mogrify -path OUTPUT_PATH -filter Triangle - define filter:support=2.0 -thumbnail

    OUTPUT_WIDTH -unsharp 0.25x0.25+8.00+0.065 - dither None -posterize 136 -background Black - alpha Background -quality 82 -define jpeg:fancy- upsampling=off -define png:compression-filter=5 -define png:compression-level=9 -define png:compression-strategy=1 -define png:exclude- chunk=all -interlace none -colorspace sRGB - strip INPUT_PATH

  60. 59 mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2.0 -thumbnail OUTPUT_WIDTH

    -unsharp 0.25x0.08+8.3+0.045 -dither None - posterize 136 -quality 82 -define png:preserve-colormap=true - interlace none INPUT_PATH

  61. 60 mogrify -path OUTPUT_PATH -filter Triangle - define filter:support=2.0 -thumbnail

    OUTPUT_WIDTH -unsharp 0.25x0.25+8.00+0.065 - dither None -posterize 136 -background Black - alpha Background -quality 82 -define jpeg:fancy- upsampling=off -define png:compression-filter=5 -define png:compression-level=9 -define png:compression-strategy=1 -define png:exclude- chunk=all -interlace none -colorspace sRGB - strip INPUT_PATH

  62. 61

  63. 62 mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2.0 -thumbnail OUTPUT_WIDTH

    -unsharp 0.25x0.08+8.3+0.045 -dither None - posterize 136 -quality 82 -define png:preserve-colormap=true - interlace none INPUT_PATH

  64. 63

  65. 63

  66. 64

  67. 64

  68. 65 Progressive JPEGs Good? Evil?

  69. 66 mogrify -path OUTPUT_PATH -filter Triangle - define filter:support=2.0 -thumbnail

    OUTPUT_WIDTH -unsharp 0.25x0.25+8.00+0.065 - dither None -posterize 136 -background Black - alpha Background -quality 82 -define jpeg:fancy- upsampling=off -define png:compression-filter=5 -define png:compression-level=9 -define png:compression-strategy=1 -define png:exclude- chunk=all -interlace none -colorspace sRGB - strip INPUT_PATH

  70. 67

  71. 68 mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2.0 -thumbnail OUTPUT_WIDTH

    -unsharp 0.25x0.08+8.3+0.045 -dither None - posterize 136 -quality 82 -define png:preserve-colormap=true - interlace none INPUT_PATH With optimization:

  72. 69 mogrify -path OUTPUT_PATH -filter Triangle - define filter:support=2.0 -thumbnail

    OUTPUT_WIDTH -unsharp 0.25x0.25+8.00+0.065 - dither None -posterize 136 -background Black - alpha Background -quality 82 -define jpeg:fancy- upsampling=off -define png:compression-filter=5 -define png:compression-level=9 -define png:compression-strategy=1 -define png:exclude- chunk=all -interlace none -colorspace sRGB - strip INPUT_PATH Without optimization:

  73. 70 Why even bother?

  74. 71 Condition File size: mean File size: % difference My

    settings, optimization 221,583.36 KB My settings, no optimization 260,250.18 KB 17.45% Photoshop CC, optimization 260,304.70 KB 17.48% CodeIgniter / ExpressionEngine 276,112.95 KB 24.61% Photoshop CC, no optimization 299,709.70 KB 35.26% TYPO3.CMS 321,602.95 KB 45.14% WordPress 337,665.98 KB 52.39% Drupal 344,246.42 KB 55.36% Perch 348,735.82 KB 57.38% Craft CMS 372,055.63 KB 67.91% grunt-responsive-images 426,623.28 KB 92.36%

  75. 72 OK… but it’s still a pain in the butt

  76. 73 https://www.npmjs.com/package/grunt-respimg

  77. 74 Resizing with smart defaults SVG to PNG rasterization Optimization

  78. 75 npm install grunt-respimg --save-dev

  79. 76

  80. 77

  81. David Newton, St. Michael’s Hospital 78 1 Using ImageMagick to

    resize your Images Toronto Web Performance Group, 2015-03-17 Twitter: @newtron Github: @nwtn Email: [email protected] Slides + image credits: https://github.com/nwtn/pres-imagemagick-webperfto