Presentation by Leif Arne Rønningen, Item, NTNU, Autumn 2008
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Transcript of Presentation by Leif Arne Rønningen, Item, NTNU, Autumn 2008
TTM4142 Networked Multimedia Systems
Stereo Analyses by Hybrid Recursive Matching (HRM) for Real-Time Immersive Video
Conferencing
Presentation by Leif Arne Rønningen, Item, NTNU, Autumn 2008
N Atzpadin, P Kauff, O SchreerIEEE Transactions on circuits and systems for video technology
Vol. 14, no 3, March 2004
Stereo correspondence search by HRM. The output disparity maps give the pixel correspondences of the left and right images
Two-camera model, rectification
The HRM algorithm - outline
HRM outline behaviour
• For the current image block posisiton do:• The selection-of-start-vector function evaluates three
candidate vectors for the current block posisiton, and outputs the vector with the smallest DBD (displaced block difference) as the start vector for pixel-recursion
• The pixel-recursion function outpus an update vector with the smallest DPD (displaced pixel difference)
• The selection-of-final-vector function selects as the final vector the one with the smallest DBD
Block Recursion
• The three candidate vectors are calculated using information of both the previous image and the spatial neighborhood
• Spatial candidate vectors are found using meander scan <link>
• Spatial candidates in the right image are equally distributed around the considered pixel in the left and right image
• A temporal candidate vector is taken from the same position in the previous frame <link>
Meander scan for arbitrarily shaped video objects
Even frames Odd frames
Shape driven displaced block difference - DBD
Pixel RecursionDisplaced pixel difference - DPD
Outline of pixel recursion
Mean absolute difference between candidateand final output vector
Frequency of identity between candidat andfinal output vector
Spatial distribution of squared difference betweenfinal output vector and candidate
Horizontal Vertical
Temporal Update
Spatial distribution of squared difference betweenfinal output vector and candidate
HRM applied to left and right images
Left-to-right Right-to-left disparities disparities
Result of the consistency check (unreliable disparities are marked as black).
Synthesized views (a) without postprocessing, (b) with consistency check and simple interpolation, and (c) with segmentation based postprocessing.
Zoom of the critical hand area in synthesized views from previous Figure(a) without postprocessing, (b) with consistency check and simple interpolation, and(c) with segmentation based postprocessing.