Volumetric Image Compression with CS-EBCOT
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VOLUMETRIC VOLUMETRIC IMAGE IMAGE
COMPRESSION COMPRESSION WITH CSWITH CS--EBCOTEBCOT
Xavier Giró i NietoPhilippe Salembier Universitat Politècnica de Catalunya - ETSETB
Peter SchelkensJan CornelisVrije Universiteit Brussels - ETRO
Xavier Giró i Nieto ([email protected]) 2
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTINTRODUCTIONINTRODUCTION
Encoder Embedded coder Embedded coder
Bit-stream Structured bit-stream Structured bit-stream
Image compression techniques
1st generationstrcuture derived
from coderEx. JPEG
2nd generationstrcuture derived
from coder
3rd generationabstract interface
between coder andbit-stream structures
Xavier Giró i Nieto ([email protected]) 3
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTINTRODUCTIONINTRODUCTION
Embedded coder
Structured bit-stream
3rd generationabstract interface
between coder andbit-stream structures
• 3rd generation coders (JPEG200)- support for lossles and lossy- enable rate scalability, quality and resolution scalability
• volumetric images ?(Ex. medical)
• 2D techniques slice by sliceexploit correlation only throughX and Y axis
Xavier Giró i Nieto ([email protected]) 4
adapt the VM 6.0 EBCOT coder to support volumetric images including a Cube-Splitting front end.study the performance of– CS-EBCOT for lossless and lossy coding– new wavelet filters– 3D Morton scanning pattern– models of a context-based adaptive arithmetic
coder
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTTARGETSTARGETS
Xavier Giró i Nieto ([email protected]) 5
CS-EBCOT codec is – always outperforming Cube-Splitting and
3D SPIHT coding engine in lossless coding– giving good results for lossy coding,
especially at low bit-rates when comparing with PSNR
– giving the best visual quality for lossy coding
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTRESULTSRESULTS
Xavier Giró i Nieto ([email protected]) 6
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTGENERAL SCHEMEGENERAL SCHEME
3D wavelettransform Tier 1 Tier 2
INPUT IMAGE-raw data from 1 to 32 bits-medical, multispectral, ...
3D EBCOT CODER
Xavier Giró i Nieto ([email protected]) 7
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOT3D WAVELET3D WAVELETL
H
2
2
L
H
2
2x
d1
d2
s2
s2 d2
Level 1 (Finest level)Level 2 (Coarsest level)
d1
- apply the wavelet transformin the three spatial directions
- subband organization
Xavier Giró i Nieto ([email protected]) 8
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTGENERAL SCHEMEGENERAL SCHEME
3D wavelettransform Tier 1 Tier 2
3D EBCOT CODER
WAVELET COEFFICIENTS-distributed in subbands and decomposition levels
INPUTIMAGE
Xavier Giró i Nieto ([email protected]) 9
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTCODEBLOCKSCODEBLOCKS
HLL HHL
HLL HHL
LLL LHLLHL
LLH LHH
HHH
LLH LHH
CODING UNIT:the codeblock
Xavier Giró i Nieto ([email protected]) 10
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTCODEBLOCKSCODEBLOCKSCODING UNIT:the codeblock
• each codeblock iscoded independently• zero coefficientsare added whenoutcoming the borders
Xavier Giró i Nieto ([email protected]) 11
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTGENERAL SCHEMEGENERAL SCHEME
3D wavelettransform Tier 1 Tier 2
3D EBCOT CODER
TIER 1-embedded block coding-operates on block samples
INPUTIMAGE
WAVELETCOEFFICIENTS
...
CODEBLOCKS
Xavier Giró i Nieto ([email protected]) 12
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTEBCOT TIER 1EBCOT TIER 1Octree cube
spliiting
Fractionalbit-planecodingCODEBLOCK
OCTREE CUBE SPLITTING-identifies subblocks in the codeblockwhich contain significant information for present bit-plane
FOR EACH BIT-PLANE
Xavier Giró i Nieto ([email protected]) 13
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTOCTREE CODINGOCTREE CODING
SGN
SGNNSNSNSNSNSNSNS
SGNNSNSNSNSNSNSNS
SGN = SignificantNS = Non-significant
Xavier Giró i Nieto ([email protected]) 14
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTEBCOT TIER 1EBCOT TIER 1Octree cube
spliting
Fractionalbit-planecodingCODEBLOCK
FOR EACH BIT-PLANE
SIGNIFICANTSUBBLOCK
FRACTIONAL BIT-PLANE CODING• four context-based coding operations • three coding passes
• Significance Propagation• Magnitude Refinement• Normalization
Xavier Giró i Nieto ([email protected]) 15
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTSCANNINGSCANNING
x
yz
2D JPEG2000 slice by slice
Xavier Giró i Nieto ([email protected]) 16
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTSCANNINGSCANNINGMorton scanning pattern
2D Morton 3D Morton x
yz
Xavier Giró i Nieto ([email protected]) 17
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOT3D CONTEXTS3D CONTEXTS
• four coding operations:- Run-Length Coding (RLC)- Zero Coding (ZC)- Sign coding (SC)- Magnitude Refinement Coding (MR)
• original 2D contexts wereadapted to 3D (more complex)
• from the 8 neighbours in 2D to26 neighbours with 3 categoriesin 3D
closer
Xavier Giró i Nieto ([email protected]) 18
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTCODING PASSESCODING PASSES3 coding passes are applied in every bit-plane
• SIGNIFICANCE PASSNeighbours of already previous significant coefficients
• MAGNITUDE REFINEMENT PASSCoefficients already marked as asignificant
• NORMALIZATION PASSRest of the coefficients
Xavier Giró i Nieto ([email protected]) 19
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTCODING PASSESCODING PASSESbit-plane
x
y
presentbit-plane
on a 2D image
Significance passMagnitude refinement passNormalization passnot processed in the present bit-plane
Xavier Giró i Nieto ([email protected]) 20
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTTRUNCATIONTRUNCATION
O[pmax] +P[pmax,3] P[pmax-1,1] P[pmax-1,2] O[pmax-1] +
P[pmax-1,3]O[pmax-1] +P[pmax-1,3]P[0,2]P[0,1]
rate
distortion
O[pmax] +P[pmax,3] P[pmax-1,1] P[pmax-1,2] O[pmax-1] +
P[pmax-1,3]O[pmax-1] +P[pmax-1,3]P[0,2]P[0,1]
Where to truncate ?
one bit-stream foreach code block
Xavier Giró i Nieto ([email protected]) 21
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTEBCOT TIER 1EBCOT TIER 1Octree cube
spliting
Fractionalbit-planecodingCODEBLOCK
FOR EACH BIT-PLANE
SIGNIFICANTSUBBLOCK
EMBEDDEDBLOCK
STREAM
EMBEDDED BLOCK BIT-STREAM• one bit-stream for each codeblock• one possible truncation point associated to the end of each pass• a distortion associated to each truncation pass
Xavier Giró i Nieto ([email protected]) 22
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTGENERAL SCHEMEGENERAL SCHEME
3D wavelettransform Tier 1 Tier 2
3D EBCOT CODER
TIER 2-coding of block contributions to each quality layer-operates on block summary info
INPUTIMAGE
WAVELETCOEFFICIENTS
...
CODEBLOCKS
EMBED.STREAM
Xavier Giró i Nieto ([email protected]) 23
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTEBCOT TIER 2EBCOT TIER 2• T2 generates a packet for each resolution level in each quality layer
Body (code bytes)Header
FOR EACH CODEBLOCK-first inclusion layer (tag tree)-maximum bit-depth (tag tree)-number of new coding passes included in body-number of new bytes included in the body
Xavier Giró i Nieto ([email protected]) 24
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTEBCOT TIER 2EBCOT TIER 2layer 1 layer 2 layer Λ -1 layer Λ
resolution L resolution L-1 resolution 1 resolution 0
LLL HLL LHL HHL LLH HLH LHH HHH
header code bytes
inclusion layer insignificant msbs number of passes number of bytes
block 0 block 1 block 2 block N
Xavier Giró i Nieto ([email protected]) 25
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTGENERAL SCHEMEGENERAL SCHEME
3D wavelettransform Tier 1 Tier 2
3D EBCOT CODER
INPUTIMAGE
WAVELETCOEFFICIENTS
...
CODEBLOCKS
EMBED.STREAM
COMPRESSEDFILE
Xavier Giró i Nieto ([email protected]) 26
further experiments with size of codeblocksimprove arithmetic coder
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTFUTURE WORKFUTURE WORK
Xavier Giró i Nieto ([email protected]) 27
JPEG2000 principles are fully aplicable for 3D imagesoctree front end is a valuable toolInteger 5x11 is the best integer kernel for lossy and lossless compressionno gain in using Morton scanning
VOLUMETRIC IMAGECOMPRESSION
WITH CS-EBCOTCONCLUSIONSCONCLUSIONS