幻灯片 1shiboxin/files/Shi_ICME09...Key Laboratory of Machine Perception (Ministry of Education)...
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ICME2009 BLOCK-BASED COLOR CORRECTION ALGORITHM FOR MULTI-VIEW VIDEO CODING Boxin Shi, Yangxi Li, Lin Liu, Chao Xu Key Laboratory of Machine Perception (Ministry of Education) Peking University, Beijing, China Lectured by: Boxin Shi ([email protected])
Transcript of 幻灯片 1shiboxin/files/Shi_ICME09...Key Laboratory of Machine Perception (Ministry of Education)...
ICME2009BLOCK-BASED COLOR CORRECTION ALGORITHM
FOR MULTI-VIEW VIDEO CODING
Boxin Shi, Yangxi Li, Lin Liu, Chao XuKey Laboratory of Machine Perception (Ministry of Education)Peking University, Beijing, China
Lectured by: Boxin Shi ([email protected])
Outline
1
Problem
MVC
Color Correction
Existed works
2
Algorithm
3
Result
Workflow
Colorization
Local-to-global
Picture
Histogram
Table
Outline
1
Problem
MVC
Color Correction
Existed works
2
Algorithm
3
Result
Workflow
Colorization
Local-to-global
Picture
Histogram
Table
1. Problem
Multi-view Video Coding (MVC)
[1] W. Matusik, H. Pfister. “3DTV: A scalable system for real-time acquisition,
transmission, and autostereoscopic display of dynamic scenes”, ACM
Transactions on Graphics, 2004, 23(3): 814-824.
[2] Tanimoto Lab, Nagoya University. http://www.tanimoto.nuee.nagoya-u.ac.jp.
[1]
[2]
• New experience in video
• Challenge: huge data
• Similarity in different views
• Temporal VS. spatial motion
compensation
1. Problem
Color variation among different views
[3] ISO/IEC JTC1/SC29/WG11, “KDDI Multi-View Video Sequences for MPEG
3DAV Use”, MPEG2004/M10533, Munich, Mar. 2004.
[1]
[2]
• Unavoidable cause
scene illumination
camera calibration
jitter speed
• Bad effects to
visual quality
coding efficiency
[3]
[4] U. Fecker, M. Barkowsky, A. Kaup, “Histogram-Based Prefiltering for Luminance
and Chrominance Compensation of Multiview Video”, IEEE Trans. Circuits & Systems
for Video Technology, vol. 18(9), pp. 1258 – 1267, Sep. 2008.
[5] Y. Chen, C. Cai, J. Liu, “YUV Correction for Multi-View Video Compression”,
ICPR2006, Hong Kong, pp. 734 – 737, Aug 2006.
1. Problem
Existed color correction methods
[1]
[2]
[3]
Outline
1
Problem
MVC
Color Correction
Existed works
2
Algorithm
3
Result
Workflow
Colorization
Local-to-global
Picture
Histogram
Table
2. Algorithm
Overall workflow
[1]
[2]
[3]
2. Algorithm
Colorization scheme
[1]
[2]
[3]• Scribble-based
color blocks as scribbles
• Y guides U/V
similar intensity ~ similar color
• Optimization [6]
[6] A. Levin, D. Lischinski, Y. Weiss, “Colorization
using Optimization”, ACM Trans. Graph., vol. 23(3),
pp. 689 – 694, Aug. 2004.
2. Algorithm
Global mixture
[1]
[2]
[3]• Block scribble shortcomings
square is not enough
color bleeding
• Global refinement
detect wrongly colored pixels
color transfer [7]
lαβ color space
[7] E. Reinhard, M. Ashikhmin, B. Gooch, and P.
Shirley, Color transfer between images, IEEE
Computer Graphics Applications, vol. 21(5), pp.
34 – 41, 2001.
Outline
1
Problem
MVC
Color Correction
Existed works
2
Algorithm
3
Result
Workflow
Colorization
Local-to-global
Picture
Histogram
Table
3. Result
Picture (Visual quality comparison)
[1]
[2]
[3]
• Unavoidable cause:
scene illumination
camera calibration
jitter speed
• Bad effects to:
visual quality
coding efficiency
3. Result
Histogram (YUV space)
[1]
[2]
[3]
3. Result
Table (ratio of best matching blocks in spatial prediction)
[1]
[2]
[3]• Spatial motion compensation
• Ratio = No. of best matching blocks / total No.
• Partially reflect the correction effectiveness
• PSNR can be influence by various factors
