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Stereo Matching. Information Permeability For Stereo Matching Cevahir Cigla and A.Aydın Alatan Signal Processing: Image Communication, 2013 Radiometric Invariant Stereo Matching Based On Relative Gradients Xiaozhou Zhou and Pierre Boulanger
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Stereo Matching • Information Permeability For Stereo Matching • Cevahir Cigla and A.Aydın Alatan • Signal Processing: Image Communication, 2013 • Radiometric Invariant Stereo Matching Based On Relative Gradients • Xiaozhou Zhou and Pierre Boulanger • International Conference on Image Processing (ICIP), IEEE 2012
Outline • Introduction • Related Works • Methods • Conclusion
Introduction • Goal • Get accurate disaprity maps effectively. • Find more robust algorithm, especially refinement technique. • Foucus : Refinement step and Comparison
Related Works • StereoMatching • Thesameobject,thesamedisparity • Segmentation • Calculatecorrespondpixelssimilarity(colorandgeographic distance) • Occlusionhandling • Refinement
Related Works • GlobalMethods • Energy minimization process (GC,BP,DP,Cooperative) • Per-processing • Accuratebutslow • LocalMethods • A local support region with winner take all • Fastbutinaccurate. • AdaptiveSupportWeight
RelatedWorks • Local methodsalgorithm [1] D. Scharstein and R. Szeliski. A taxonomy and evaluation of dense two-frame stereo correspondence algorithms. International Journal of Computer Vision (IJCV), 47:7–42, 2002.
Related Works • Edge Preserving filter:Remove noise and preserve structure/edge,likeobjectconsideration. • AdaptiveSupportWeight[3] • Bilateral filter(BF) [34] • Guided filter(GF)[5] • Geodesicdiffusion[33] • ArbitrarySupportRegion [39]
Reference Papers [3] Kuk-JinYoon, InSoKweon, Adaptive support weight approach for correspondence search, IEEE Transactions on Pattern Analysis and Machine Intelligence, 2006. [5] C. Rhemann, A. Hosni, M. Bleyer, C. Rother, M. Gelautz, Fast cost-volume filtering for visual correspondence and beyond, CVPR 2011. [33] L. De-Maetzu, A. Villanueva nad, R. Cabeza, Near real-time stereo matching using geodesic diffusion, IEEE Transactions on Pattern Analysis and Machine Intelligence, 2012. [34] A. Ansar, A. Castano, L. Matthies, Enhanced real time stereo using bilateral filtering, in: Proceedings of the International Symposium on 3D Data Processing Visualization and Transmission, 2004. [39] X. Mei, X Sun, M Zhou, S. Jiao, H. Wang, Z. Zhang, On building an accurate stereo matching system on graphics hardware, in: Proceed- ings of GPUCV 2011.
Methods A. • Goal : Gethighqualitybutlowcomplexity Savememory Real-timeapplication • SuccessiveWeightedSummation(SWS) • Constanttimefiltering+Weightedaggregation ◎Qingqing Yang, Dongxiao Li, Lianghao Wang, and Ming Zhang, “Full-Image Guided Filtering for Fast Stereo Matching”, Signal Processing Letters, IEEEMarch 2013 http://www.camdemy.com/media/7110
Methods A. • Cost Computation
Census Transform Census transform window :
Census Hamming Distance • Left image • Right image Hamming Distance = 3 XOR
Methods A. • Cost Computation
Methods A. Cost Aggregation
Methods A. • Cost Aggregation
Methods A. (c)Vertical effective weights (d)2D effective weights (b)Horizontal effective weights
Comparison With Other Methods (b) Geodesic support [12] (c) Arbitrary support region [4] (d) Proposed (a) AW [3]
Methods A. • Refinement • Using cross-check to detect reliable and occluded region detection ф is a constant (set to 0.1 throughout experiments)
Methods A. Linear mapping function for reliable pixels based on disparities (b)The resultant map for the left image
(b) Without occlusion handling, bright regions correspond to small disparities (c) Detection of occluded and un-reliable regions
Methods A. (b) occlusion handling with no background favoring (c) the proposed occlusion handling
Experimental Results A. • Device : Core Duo 1.80 GHz 2G Ram CPU • Implemented in C++ • Parameter : (T, α,)=(15, 0.2, 8)
Experimental Results A. 6D + 4D * V.S. 129D + 21D * 10~15X
Experimental Results A. • Proposed method is the fastest method without any special hardware implementation among Top-10 local methods of the Middlebury test bench, as of February 2013.
O(1) AW Guided filter Geodesic support Arbitrary shaped cross filter Proposed
Comparison with Full-Image◎ ◎Qingqing Yang, Dongxiao Li, Lianghao Wang, and Ming Zhang, “Full-Image Guided Filtering for Fast Stereo Matching”, Signal Processing Letters, IEEE
Ground Truth Proposed Results Full-Image Results
Comparison with Full-Image • My Experimental Results (SAD+Gradient) • Lowest V.S. Normalized disparity
Radiometric Invariant Stereo Matching Based On Relative Gradients MethodB.
Methods B. • Goal : Adaptdifferentenvironmentalfactors.(Illuminationcondition) Effectiveandrobustalgorithm • Relativegradientalgorithm+Gaussianweightedfunction
Background • LightingModel: • Viewindependent,bodyreflection
Background • LightingModel: ANCC
Method B. • Cost Computation
Method B. • Cost Aggregation • Refinement • AvoidWhiteandblacknoises
Experimental Results B. • My Experimental Results (SAD+Gradient) • Original V.S.Rerange disparity