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ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
FLC (NTNU) VLC
Error resilience capabilities Error resilience capabilities ((cont’dcont’d))
R=0.5 bit/pixel, ber=0.001
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
• Re-synch marker at packet boundaries• Ability to locate errors in a packet
Magic String(3 bytes)
“JP2”
Header Length(2 bytes: msb first)
HL
Global Header
( HL bytes)
Packet
Head BodyRes
ync
(2 b
ytes
) Packet
Head BodyRes
ync
(2 b
ytes
)
optional
Error resilience capabilities Error resilience capabilities ((cont’dcont’d))
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
• Re-synch marker atblock boundaries
• Locate errors in ablock
Segment Marker
Segment Marker
Segment Marker
Segment Marker
Bitplane
Bitplane
Bitplane
Bitplane
error
Code block
Error resilience capabilities Error resilience capabilities ((cont’dcont’d))
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Reversible color transformation:Reversible color transformation:making making lossless colourlossless colour coding possible coding possible
GBVr
GRUr
BGRYr
−=−=
++
=4
*2
GVrB
GUrR
VrUrYrG
+=+=
+−= )
4(
All components must have identical subsamplingparameters and same depth
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Visual Frequency WeightingVisual Frequency Weighting• Allows system designers to take advantage of
visual perception
• Fixed Visual Weighting (FVW) &Progressive Visual Coding (PVC)
• FVW: CSF are chosen according to the finalviewing condition
• Implementation: Q steps in subband I aremodified based on the CSF
• PVC: Visual weights are changes during theembedded process
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Visual frequency weighting: FVWVisual frequency weighting: FVW• modify transform coefficients by multiplying
by the CSF weight (decoder has to know)
• modify Q step sizes (decoder needs not know)
• modify the embedded coding order– the distortion weights fed to the R-D optimization are
altered
– this controls the relative significance of includingdifferent number of bitplanes from the embeddedbitstream of each code-block
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Visual frequency weighting: PVCVisual frequency weighting: PVC
• Visual weights have to be changed duringthe embedded process– difficult to change the coefficient values of Q steps– performance of entropy coder might degrade due to
changing statistics of the binary representation
• Solution– change on the fly the order in which code blocks sub
biplanes should appear in the embedded bitstreambased on the visual weights
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Weighting set 0: r(0), with w(0) = { w0
(0) , w1(0) , . . . , wn
(0)} ;Weighting set 1: r(1)
, with w(1) = { w0(1) , w1
(1) , . . . , wn(1)} ;
.
.
.Weighting set m: r(m), with w(m) = { w0
(m) , w1(m) , . . . , wn
(m)}
•Distortion metric is changed progressively based on the visual weights during bitstream formation
•Bitsream formation is driven by postprocessing R-D optimization
•Progressive visual weights control the embeddingorder of code-block sub-bitplanes on the fly
Visual frequency weighting: PVCVisual frequency weighting: PVC
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
ExampleExample0.25 bpp, TCQ(RMSE:8.81), Visual TCQ (13.53)
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Line based transformsLine based transforms
• A way for low memory implementation of thewavelet transform
• Same wavelet coefficients as full framewavelet transform
• Same encoding results as the standard VM
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Line based transforms Line based transforms ((cont’dcont’d))
VH
VL
HH
LH
HL
LL
Input image data
High pass Horizontal
High pass Horizontal
Low pass Horizontal
Low pass Horizontal
Line buffering for vertical decomposition
Low pass Vertical
High pass Vertical
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Line Buffer
Line Buffer
Line Buffer
0
1
2
3
4
Input Image
Encode
Encode
Encode
Encode
Encode
Line Buffer
Filtering Elements
Line Buffer
Line based transforms Line based transforms ((cont’dcont’d))
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Compressed image manipulationCompressed image manipulation
• Allows for– rotations of 90, 180, 270 degrees– vertical flipping (horizontal axis symmetry)– horizontal flipping (vertical axis symmetry)– all possible combinations of abovein the wavelet domain
by rearranging the quantized subbandcoefficients (no modification of the coeffs.)
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Compressed imageCompressed imagemanipulation: advantagesmanipulation: advantages
• More efficient in terms of– memory– complexity requirements
• No additional distortion is introduceddue to inverse / forward transformation
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Bit stream
entropydecoding
geometricmanipulation
entropydecoding
Transcoder
Bit stream
JPEG2000 Encoder
JPEG2000 Encoder
Update of OCB h, OCBv and T bits
originalimage
Reconstructed image Bit stream
entropydecoding
geometricmanipulation
entropydecoding
Transcoder
Bit stream
JPEG2000 Encoder
JPEG2000 Encoder
Update of OCB h, OCBv and T bits
originalimage
Reconstructed image
OCBh=0, OCBv=0, T=0
Compressed image manipulation Compressed image manipulation ((cont’dcont’d))
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Transcoding: vertical flipping on subbands
Compressed image manipulation Compressed image manipulation ((cont’dcont’d))
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Transcoding: 90 degrees rotation on subbands
Compressed image manipulation Compressed image manipulation ((cont’dcont’d))
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
• The only information needed at thedecoder are the filtering conventionorders (OCBh/OCHv) for horizontal andvertical direction
• The decoder must know if the linesand/or columns have been flipped
Compressed image manipulation Compressed image manipulation ((cont’dcont’d))
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
PostprocessingPostprocessing
• Typical artifacts in Wavelet coding areringing effects
• Postprocesing can reduce these artifacts
• Postprocesing filter based on robust M-estimator
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
PostprocessingPostprocessing ((cont’dcont’d.).)
Examples of filtering windowsExamples of filtering windows
∑=
−=N
ijix
xxxj 1
)(minargˆ ρ
))(1log()(
}1,min{)(
21,||)(
||)|(|2
||)(
221
22
2
2
γ
γγ
ργρ
γρ
γγγγγ
ρ
xxLorenzian
xxLTruncated
xxL
xx
xxxHuber
+=
=
≤≤=
>−+≤
=
P(x) characterizes the behavior of the estimator,or the smoothing capability
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
ConclusionsConclusions
• Advanced still image coding standard
• Better than current baseline JPEG
• Includes many interesting functionalities
• Intended to become the key standard for
still image coding in the next millennium
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
More informationMore information• JPEG
– http://www.jpeg.org
• EUROSTILL– http://ltswww.epfl.ch/~eurostill
• SPEAR– http://spear.jpeg.org/
• JJ2000– JavaTM JPEG2000 development– http://jj2000.epfl.ch
ICIP’99, Oct. 24-28, Kobe, JapanCharilaos Christopoulos
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
AcknowledgementsAcknowledgements• Mr. Joel Askelöf, Ericsson• Dr. Eiji Atsumi, Mitsubishi, Japan• Martin Boliek, Ricoh• Dr. Christos Chrysafis, HP Labs• Prof. Touradj Ebrahimi, EPFL• Prof. Nariman Farvardin, Univ. Maryland• Prof. Faouzi Kossentini, UBC• Mathias Larsson, Ericson• Dr. Daniel Lee, HP Labs• Dr. Eric Majani, CRF• Prof. Michael Marcellin, Univ. of Arizona• Prof. Andrew Perkis, NTNU• Dr. Majid Rabbani, Kodak• Dr. David Taubman, HP Labs & Univ. New South Wales
**
* In alphabetical order* In alphabetical order
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
Thank you for your attention!Thank you for your attention!
ERICSSON RESEARCH
Media Lab
UNIVERSITY OF PATRAS
Electronics Laboratory
C.A.C.A.ChristopoulosChristopouloscharilaos.christopoulos@era.ericsson.se