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The 
JPEG 
S*ll 
Picture 
Compression 
Standard 
by 
Gregory 
K. 
Wallace, 
1991 
Julià 
Minguillón 
Barcelona 
Compsci 
C...
Contents 
• Why 
a 
talk 
on 
JPEG? 
• Previous 
to 
JPEG 
• Technology 
at 
that 
Fme 
• The 
paper 
• Math 
foundaFons 
...
Why 
a 
talk 
on 
JPEG? 
• JPEG 
images 
are 
everywhere! 
– Facebook: 
350000000 
photos 
uploaded 
every 
day 
– Almost ...
Lena 
512 
x 
512 
x 
24bpp 
hZp://sipi.usc.edu/database/?volume=misc
Previous 
to 
JPEG 
• … 
• TIFF 
1986 
• GIF 
1987 
• PBM 
1991 
• … 
• Limited 
compression 
raFos 
(lossless) 
• No 
sta...
Technology 
at 
that 
Fme 
• 1991: 
Kodak 
DCS 
100, 
1.3MP, 
200MB 
HD, 
only 
987 
sold 
(aimed 
at 
photojournalists, 
...
The 
paper 
Wallace, 
G.K. 
(1991). 
The 
JPEG 
sFll 
picture 
compression 
standard. 
CommunicaFons 
of 
the 
ACM 
– 
spe...
Math 
foundaFons 
• Lossy 
compression 
≈ 
remove 
what 
eye 
can’t 
see 
• Karhunen-­‐Loève 
transform: 
any 
stochasFc 
...
The 
algorithms 
• Color 
conversion 
from 
R-­‐G-­‐B 
to 
Y-­‐Cb-­‐Cr 
• Sampling 
and 
interleaving 
• DCT 
• QuanFzaFon...
Impact 
• All 
devices 
taking 
pictures 
implement 
JPEG 
• JPEG 
File 
Interchange 
Format 
(.jpg, 
.jpeg) 
• IJG 
libra...
Caveats 
• 8 
x 
8 
blocks 
are 
too 
small 
• “Limited” 
to 
12 
bit 
samples 
• Bad 
quality 
for 
high 
compression 
ra...
Related 
papers 
Rao, 
K.R., 
Yip, 
P. 
(1990). 
Discrete 
Cosine 
Transform 
algorithms. 
Advantages, 
ApplicaFons. 
Acad...
JPEG 1991 GK Wallace paper on JPEG standard
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JPEG 1991 GK Wallace paper on JPEG standard

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A review of the 1991 Wallace's paper on JPEG standard

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JPEG 1991 GK Wallace paper on JPEG standard

  1. 1. The JPEG S*ll Picture Compression Standard by Gregory K. Wallace, 1991 Julià Minguillón Barcelona Compsci Club
  2. 2. Contents • Why a talk on JPEG? • Previous to JPEG • Technology at that Fme • The paper • Math foundaFons • The algorithms • Impact • Caveats • Related papers
  3. 3. Why a talk on JPEG? • JPEG images are everywhere! – Facebook: 350000000 photos uploaded every day – Almost 1000000000000 photos taken every year! • 1995 capstone project at UAB – ImplementaFon of progressive operaFon modes in IJG library v6b • Perfect excuse for checking over Lena again!
  4. 4. Lena 512 x 512 x 24bpp hZp://sipi.usc.edu/database/?volume=misc
  5. 5. Previous to JPEG • … • TIFF 1986 • GIF 1987 • PBM 1991 • … • Limited compression raFos (lossless) • No standard for lossy image compression • JPEG commiZee created in 1986 (ISO in 1983)
  6. 6. Technology at that Fme • 1991: Kodak DCS 100, 1.3MP, 200MB HD, only 987 sold (aimed at photojournalists, 20000$) • 1994: Apple QuickTake 100, 0.3MP (VGA), 749$ • … • Computers in 1991: Intel 486DX, MS-­‐DOS 5.0, Windows 3.0, Linux, VGA (640x480x256 -­‐ yes, Amiga was beZer!), Adobe Photoshop 2.0, 1st color image scanner (HP)
  7. 7. The paper Wallace, G.K. (1991). The JPEG sFll picture compression standard. CommunicaFons of the ACM – special issue on digital mulFmedia systems, 34(4), 30-­‐44. • Summary of JTC1/SC2/WG10 • Already a classic (> 4500 cites) hZp://www-­‐ee.eng.hawaii.edu/~treed/EE416/ Project_4/jpeg-­‐wallace.pdf
  8. 8. Math foundaFons • Lossy compression ≈ remove what eye can’t see • Karhunen-­‐Loève transform: any stochasFc process can be decomposed in an infinite linear combinaFon of orthogonal funcFons – Coefficients are decorrelated – Any truncaFon minimizes MSE • Discrete cosine transform – Similar to DFT but real coefficients – Existence of fast / reversible / integer versions
  9. 9. The algorithms • Color conversion from R-­‐G-­‐B to Y-­‐Cb-­‐Cr • Sampling and interleaving • DCT • QuanFzaFon (loss/compression happens here) • Reordering (zig-­‐zag sequence) • Entropy coding: zeros, markers • Symmetrical process for coding / encoding
  10. 10. Impact • All devices taking pictures implement JPEG • JPEG File Interchange Format (.jpg, .jpeg) • IJG library used elsewhere • Hardware encoders / decoders available • Part also of M-­‐JPEG (prior to MPEG-­‐4) • Superseded by JPEG2000 (but…)
  11. 11. Caveats • 8 x 8 blocks are too small • “Limited” to 12 bit samples • Bad quality for high compression raFons • ArithmeFc coding not used due to patents • HVS opFmizaFon barely used • In general, most devices/apps do not allow users to specify all JPEG parameters • Awful results if wrongly used (text, diagrams)
  12. 12. Related papers Rao, K.R., Yip, P. (1990). Discrete Cosine Transform algorithms. Advantages, ApplicaFons. Academic Press, Inc. London. Huffman, D.A. (1962). A method for the construcFon of minimum redundancy codes. In Proceedings of the IRE, 40, 1098-­‐1101. Pennebaker, W.B., Mitchell, J.L. (1993). JPEG SFll image data compression standard. Van Nostrand Reinhold, New York. Peterson, H.A., Ahumada, A.J., Watson, A.B. (1993). An Improved DetecFon Model for DCT Coefficient QuanFzaFon. In Human Vision, Visual Processing, and Digital Display IV, ed. B.E. Rogowitz and J. Allebach, Proc. 1913, 191-­‐201. Minguillón, J., Pujol, J. (2001). JPEG standard uniform quanFzaFon error modeling with applicaFons to sequenFal and progressive operaFon modes. Journal of Electronic Imaging, 10(2), 475-­‐485.

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