3D SHAPES. PYRAMID The pyramid has 5 faces. The pyramid has 5 vertices. The pyramid has 8 edges.
Comparison Study on the Performance of Critically Sampled Pyramid vs. Over-Complete Pyramid
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Sangeun Han and Yi Liang Dec. 4, 2000 Comparison Study on the Performance of Critically Sampled Pyramid vs. Over-Complete Pyramid
description
Comparison Study on the Performance of Critically Sampled Pyramid vs. Over-Complete Pyramid. Overview. Introduction of multiresolution and pyramid coding Critically sampled and overcomplete pyramids Bit allocation and quantization Comparison and results. Multiresolution and Pyramid Coding. - PowerPoint PPT Presentation
Transcript of Comparison Study on the Performance of Critically Sampled Pyramid vs. Over-Complete Pyramid
Sangeun Han and Yi Liang
Dec. 4, 2000
Comparison Study on the Performance of Critically Sampled Pyramid vs. Over-Complete Pyramid
EE 368B Project Sangeun Han and Yi Liang
Overview Introduction of multiresolution and
pyramid coding Critically sampled and
overcomplete pyramids Bit allocation and quantization Comparison and results
EE 368B Project Sangeun Han and Yi Liang
Multiresolution and Pyramid Coding
r=0.09, 0.23, 0.60, 1.00 bpp
Multiresolution offers excellent coding efficiency.
Multiresolution supports scalability.
EE 368B Project Sangeun Han and Yi Liang
Critically Sampled PyramidH1
H0
2
2H1
H0
2
2
Q
2
2
G1
G02+
2 G1
G0+Input Recon.
ChannelOctave subband coding
Original Image Decomp. Subbands
EE 368B Project Sangeun Han and Yi Liang
Oversampled Pyramid
EE 368B Project Sangeun Han and Yi Liang
Choosing the FiltersChoosing filters
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0 1 2 3 4 5Rate [bpp]
PSN
R [d
B]
Gaussian
Decimate/Interp.
Avg./Bilinear
EE 368B Project Sangeun Han and Yi Liang
Bit Allocation Analytical form
Critically sampled, open-loop oversampled
The “greedy” algorithm
Mnkkkk
lllll kng
ngMRr /2
2
2 )/(/
log21
Close-loop oversampled
,0
0,log21
1
0
211
2
2
lrnR
lgg
r
L
lll
lll
lll
,
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1
1
1
1
,1
0,
lll
ll
ll
ll
lll
nnnnnnn
nnnn
where
.constdrndD
ll
l
EE 368B Project Sangeun Han and Yi Liang
Comparison of Rate-distortion Performance
R-D performance comparison
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0 1 2 3 4 5Rate [bpp]
PSN
R [d
B]
Oversampled open-loop, greedy bit alloc.
Oversampled open-loop, analytical bitalloc.Oversampled close-loop, L=5
Critially sampled,analytical bit alloc.
Critically sampled,greedy bit alloc.
In general, critically sampled outperforms oversampled in terms of rate-distortion. Reason: oversampling.
EE 368B Project Sangeun Han and Yi Liang
ScalabilityCritically sampled Overcomplete
PSNR = 28.4 dB
PSNR = 25.8 dB
PSNR = 28.4 dB
PSNR = 22.8 dB
PSNR = 27.2 dB PSNR = 27.2 dB
PSNR = 23.8 dB PSNR = 20.9 dB
EE 368B Project Sangeun Han and Yi Liang
Number of LayersR-D performance by using different number of levels,
open-loop oversampled
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PSN
R [d
B]
L=2L=3L=4L=5L=6
R-D performance by using different number of levels, critically sampled
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PSN
R [d
B] L=2
L=3
L=4
L=5
L=6
Critically sampled Overcomplete
EE 368B Project Sangeun Han and Yi Liang
Conclusions Critically sampled pyramid outperforms
the over-complete pyramid in terms of rate-distortion.
Coarse images from overcomplete pyramids show better subjective quality.
Other features of overcomplete pyramid: lower complexity, freedom in choosing filters, control of quantization noise.
