Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Squeezing PNG and JPEG
Search
Ariya Hidayat
July 27, 2017
Programming
2
420
Squeezing PNG and JPEG
Presented at ForwardJS Summit July 2017.
Ariya Hidayat
July 27, 2017
Tweet
Share
More Decks by Ariya Hidayat
See All by Ariya Hidayat
RAG for Small LLM
ariya
0
160
Vector Search and LLM
ariya
0
140
Making a Bigger Impact with Open Source
ariya
0
88
Practical Testing of Firebase Projects
ariya
0
110
Practical CI/CD for React Native
ariya
0
130
Hijrah ke TypeScript
ariya
0
470
Unggul dan Berdikari dengan Open-source
ariya
0
290
Practical CI/CD for React Native
ariya
1
470
Integrasi Berkesinambungan untuk React Native
ariya
1
410
Other Decks in Programming
See All in Programming
XP, Testing and ninja testing
m_seki
3
250
dbt民主化とLLMによる開発ブースト ~ AI Readyな分析サイクルを目指して ~
yoshyum
3
1k
Azure AI Foundryではじめてのマルチエージェントワークフロー
seosoft
0
170
AI駆動のマルチエージェントによる業務フロー自動化の設計と実践
h_okkah
0
150
iOS 26にアップデートすると実機でのHot Reloadができない?
umigishiaoi
0
130
今ならAmazon ECSのサービス間通信をどう選ぶか / Selection of ECS Interservice Communication 2025
tkikuc
21
4k
#QiitaBash MCPのセキュリティ
ryosukedtomita
1
1.3k
20250628_非エンジニアがバイブコーディングしてみた
ponponmikankan
0
680
ソフトウェア品質を数字で捉える技術。事業成長を支えるシステム品質の マネジメント
takuya542
1
13k
なぜ適用するか、移行して理解するClean Architecture 〜構造を超えて設計を継承する〜 / Why Apply, Migrate and Understand Clean Architecture - Inherit Design Beyond Structure
seike460
PRO
3
770
設計やレビューに悩んでいるPHPerに贈る、クリーンなオブジェクト設計の指針たち
panda_program
6
2.1k
地方に住むエンジニアの残酷な現実とキャリア論
ichimichi
5
1.5k
Featured
See All Featured
Large-scale JavaScript Application Architecture
addyosmani
512
110k
Automating Front-end Workflow
addyosmani
1370
200k
Become a Pro
speakerdeck
PRO
29
5.4k
Improving Core Web Vitals using Speculation Rules API
sergeychernyshev
18
970
4 Signs Your Business is Dying
shpigford
184
22k
What’s in a name? Adding method to the madness
productmarketing
PRO
23
3.5k
Refactoring Trust on Your Teams (GOTO; Chicago 2020)
rmw
34
3.1k
Let's Do A Bunch of Simple Stuff to Make Websites Faster
chriscoyier
507
140k
Creating an realtime collaboration tool: Agile Flush - .NET Oxford
marcduiker
30
2.1k
How to Create Impact in a Changing Tech Landscape [PerfNow 2023]
tammyeverts
53
2.9k
How to Think Like a Performance Engineer
csswizardry
25
1.7k
Measuring & Analyzing Core Web Vitals
bluesmoon
7
510
Transcript
Squeezing PNG & JPEG The Lazy Person's Guide https://unsplash.com/photos/srd-rZ5fcFw
None
None
Objective Deliver a two-dimensional array of colors in the smallest
possible PNG/JPEG file without any noticeable loss in visual quality
Optimal File size Visual quality Ideal Unacceptable
010110010101 01011001010101 0100 1001010110010101010100 1001 0101100101010101001001 01011001010101010010010 101 Encoding Decoding
010110010101 01011001010101 0100 1001010110010101010100 1001 0101100101010101001001 01011001010101010010010 101 010110010101 01011001010101
0100 1001010110010101010100 1001 0101100101010101001001 01011001010101010010010 101 Lossless Lossy Not identical vs the original
.jpg 8 megapixels JPEG Quality 95 2,210 KB MozJPEG Q
= 84 879 KB 2 seconds .jpg Guetzli 5 minutes 877 KB
https://unsplash.com/photos/Zh6C3GydNBA Squeezing PNG
Portable Network Graphics Lossless encoding Truecolor RGB RGB+A Indexed Color
Grayscale RFC 2083 http://www.w3.org/TR/PNG/ Good compression (using DEFLATE) 8 bits/channel
DEFLATE = Lempel-Ziv + Huffman RFC 1951
Lempel-Ziv: De-duplication 'Cause the players gonna play, play, play, play,
play 'Cause the players gonna play, play, play, play, play 'Cause the players gonna[5:14], play, play, play, play 'Cause the players gonna[5:14], [6:6]play, play, play
None
Color Deduplication
PNG Color Channels
PNG Compression Efficiency https://encode.ru/threads/1725-pngthermal-pseudo-thermal-view-of-PNG-compression-efficiency
Duplication Search Trade-offs 'Cause the players gonna play, play, play,
play, play 'Cause the players gonna[5:14], [6:6] [6:6] [6:6] [6:6] 'Cause the players gonna[5:14], [6:6] [12:12] [6:6]
Zopfli: Exhaustive DEFLATE https://ariya.io/2016/06/using-zopfli-to-optimize-png-images github.com/google/zopfli > zopflipng tiger.png tiger-small.png Optimizing
tiger.png Input size: 197220 (192K) Result size: 135325 (132K). Percentage of original: 68.616% Result is smaller
0 50 100 150 200 Original Zopfli KB PNG File
Size
Quantization of Colors https://ariya.io/2016/07/shrinking-png-images-with-quantization 9734 distinct colors only 256 colors
9734 distinct colors
only 256 colors
None
pngquant.org > pngquant --speed 1 --verbose tiger.png tiger.png: read 193KB
file made histogram...9734 colors found selecting colors...2% selecting colors...4% selecting colors...17% selecting colors...29% selecting colors...31% selecting colors...44% selecting colors...57% selecting colors...70% selecting colors...82% selecting colors...95% selecting colors...100% moving colormap towards local minimum eliminated opaque tRNS-chunk entries...59 entries transparent mapped image to new colors...MSE=1.048 (Q=96) writing 256-color image as tiger-fs8.png Quantized 1 image.
0 50 100 150 Full colors Reduced colors KB PNG
File Size
https://unsplash.com/photos/5bdKZLqeySU Squeezing JPEG
JPEG Color Space: YCbCr Luminance Chroma
Block Splitting: 8 × 8 Pixels
Spatial → Frequency Domain 40 24 15 19 28 24
19 15 38 34 35 35 31 28 27 29 40 47 49 40 33 29 32 43 42 49 50 39 34 30 32 46 40 47 46 35 31 32 35 43 38 43 42 31 27 27 28 33 39 33 25 17 14 15 19 26 29 16 6 1 -4 0 7 18 239 32 27 -12 3 -5 3 1 34 -3 -19 6 3 0 -1 1 -70 2 8 23 9 6 -1 -1 5 0 -6 11 -2 0 -1 1 -17 -3 6 6 3 -1 0 0 2 4 2 2 1 -2 0 1 -3 0 0 -1 -1 -1 0 0 1 -1 3 1 0 0 0 0 Discrete Cosine Transform (DCT)
Effects of different Quality Factor Q = 60 Q =
20 Q = 5
Quantization of DCT Coefficients 92 3 -9 -7 3 -1
0 2 -39 -58 12 17 -2 2 4 2 -84 62 1 -18 3 4 -5 5 -52 -36 -10 14 -10 4 -2 0 -86 -40 49 -7 17 -6 -2 5 -62 65 -12 -2 3 -8 -2 0 -17 14 -36 17 -11 3 3 -1 -54 32 -9 -9 22 0 1 3 90 0 -7 0 0 0 0 0 -35 -56 9 11 0 0 0 0 -84 54 0 -13 0 0 0 0 -45 -33 -0 0 0 0 0 0 -77 -39 45 0 0 0 0 0 -52 60 0 0 0 0 0 0 -15 0 -19 0 0 0 0 0 -51 19 0 0 0 0 0 0 Affected by the Q factor https://cs.stanford.edu/people/eroberts/courses/soco/projects/data-compression/lossy/jpeg/coeff.htm
Reduce Quality, Lose Details github.com/mozilla/mozjpeg > cjpeg –quality 84 original.jpg
> output.jpg 2,210 KB → 879 KB 8 megapixels Original Q=95
Alternative JPEG Encoder: Guetzli > guetzli –-quality 84 original.jpg output.jpg
github.com/google/guetzli 2,210 KB → 877 KB 8 megapixels Original Q=95
Pyschovisual Similarity github.com/google/butteraugli https://medium.com/@duhroach/reducing-jpg-file-size-e5b27df3257c MozJPEG Butteraugli score: 2.3 Guetzli Butteraugli
score: 1.9
Blurring the Background Photo by Kaizen Nguyễn on https://unsplash.com/photos/jcLcWL8D7AQ 116
KB 105 KB
https://unsplash.com/photos/FCrgmqqvl-w Summary
None
Identify trade-offs Reduce details Encode exhaustively
File size Visual quality
Further Exploration
Thank You shapesecurity.com Some artworks are from https://unsplash.com/ and http://openclipart.org.
speakerdeck.com/ariya @ariyahidayat