@inproceedings{3176,
abstract = {This paper demonstrates the high quality, real-time segmentation techniques. We achieve real-time segmentation of foreground from background layers in stereo video sequences. Automatic separation of layers from colour/contrast or from stereo alone is known to be error-prone. Here, colour, contrast and stereo matching information are fused to infer layers accurately and efficiently. The first algorithm, layered dynamic programming (LDP), solves stereo in an extended 6-state space that represents both foreground/background layers and occluded regions. The stereo-match likelihood is then fused with a contrast-sensitive colour model that is learned on the fly, and stereo disparities are obtained by dynamic programming. The second algorithm, layered graph cut (LGC), does not directly solve stereo. Instead the stereo match likelihood is marginalised over foreground and background hypotheses, and fused with a contrast-sensitive colour model like the one used in LDP. Segmentation is solved efficiently by ternary graph cut. Both algorithms are evaluated with respect to ground truth data and found to have similar performance, substantially better than stereo or colour/contrast alone. However, their characteristics with respect to computational efficiency are rather different. The algorithms are demonstrated in the application of background substitution and shown to give good quality composite video output.
},
author = {Vladimir Kolmogorov and Criminisi, Antonio and Blake, Andrew and Cross, Geoffrey and Rother, Carsten},
pages = {1186 -- 1186},
publisher = {IEEE},
title = {{Bi-layer segmentation of binocular stereo video}},
doi = {10.1109/CVPR.2005.90},
year = {2005},
}
@inproceedings{3181,
abstract = {Tree-reweighted max-product (TRW) message passing [9] is a modified form of the ordinary max-product algorithm for attempting to find minimal energy configurations in Markov random field with cycles. For a TRW fixed point satisfying the strong tree agreement condition, the algorithm outputs a configuration that is provably optimal. In this paper, we focus on the case of binary variables with pairwise couplings, and establish stronger properties of TRW fixed points that satisfy only the milder condition of weak tree agreement (WTA). First, we demonstrate how it is possible to identify part of the optimal solution - i.e., a provably optimal solution for a subset of nodes - without knowing a complete solution. Second, we show that for submodular functions, a WTA fixed point always yields a globally optimal solution. We establish that for binary variables, any WTA fixed point always achieves the global maximum of the linear programming relaxation underlying the TRW method.},
author = {Vladimir Kolmogorov and Wainwright, Martin J},
pages = {316 -- 323},
publisher = {AUAI Press},
title = {{On the optimality of tree reweighted max product message passing}},
year = {2005},
}
@inproceedings{3182,
abstract = {In the work of the authors (2003), we showed that graph cuts can find hypersurfaces of globally minimal length (or area) under any Riemannian metric. Here we show that graph cuts on directed regular grids can approximate a significantly more general class of continuous non-symmetric metrics. Using submodularity condition (Boros and Hammer, 2002 and Kolmogorov and Zabih, 2004), we obtain a tight characterization of graph-representable metrics. Such "submodular" metrics have an elegant geometric interpretation via hypersurface functionals combining length/area and flux. Practically speaking, we attend 'geo-cuts' algorithm to a wider class of geometrically motivated hypersurface functionals and show how to globally optimize any combination of length/area and flux of a given vector field. The concept of flux was recently introduced into computer vision by Vasilevskiy and Siddiqi (2002) but it was mainly studied within variational framework so far. We are first to show that flux can be integrated into graph cuts as well. Combining geometric concepts of flux and length/area within the global optimization framework of graph cuts allows principled discrete segmentation models and advances the slate of the art for the graph cuts methods in vision. In particular we address the "shrinking" problem of graph cuts, improve segmentation of long thin objects, and introduce useful shape constraints.},
author = {Vladimir Kolmogorov and Boykov, Yuri},
pages = {564 -- 571},
publisher = {IEEE},
title = {{What metrics can be approximated by geo cuts or global optimization of length area and flux}},
doi = {10.1109/ICCV.2005.252},
volume = {1},
year = {2005},
}
@inproceedings{3183,
abstract = {This paper describes two algorithms capable of real-time segmentation of foreground from background layers in stereo video sequences. Automatic separation of layers from colour/contrast or from stereo alone is known to be error-prone. Here, colour, contrast and stereo matching information are fused to infer layers accurately and efficiently. The first algorithm, Layered Dynamic Programming (LDP), solves stereo in an extended 6-state space that represents both foreground/background layers and occluded regions. The stereo-match likelihood is then fused with a contrast-sensitive colour model that is learned on the fly, and stereo disparities are obtained by dynamic programming. The second algorithm, Layered Graph Cut (LGC), does not directly solve stereo. Instead the stereo match likelihood is marginalised over foreground and background hypotheses, and fused with a contrast-sensitive colour model like the one used in LDP. Segmentation is solved efficiently by ternary graph cut. Both algorithms are evaluated with respect to ground truth data and found to have similar perfomance, substantially better than stereo or colour/contrast alone. However, their characteristics with respect to computational efficiency are rather different. The algorithms are demonstrated in the application of background substitution and shown to give good quality composite video output.},
author = {Vladimir Kolmogorov and Criminisi, Antonio and Blake, Andrew and Cross, Geoffrey and Rother, Carsten},
pages = {407 -- 414},
publisher = {IEEE},
title = {{Bi-layer segmentation of binocular stereo video}},
doi = {10.1109/CVPR.2005.91},
volume = {2},
year = {2005},
}
@inproceedings{3211,
abstract = {We present an improved bound on the advantage of any q-query adversary at distinguishing between the CBC MAC over a random n-bit permutation and a random function outputting n bits. The result assumes that no message queried is a prefix of any other, as is the case when all messages to be MACed have the same length. We go on to give an improved analysis of the encrypted CBC MAC, where there is no restriction on queried messages. Letting m be the block length of the longest query, our bounds are about mq2/2n for the basic CBC MAC and mo(1)q2/2n for the encrypted CBC MAC, improving prior bounds of m2q2/2n. The new bounds translate into improved guarantees on the probability of forging these MACs.},
author = {Bellare, Mihir and Krzysztof Pietrzak and Rogaway, Phillip},
pages = {527 -- 545},
publisher = {Springer},
title = {{Improved security analyses for CBC MACs}},
doi = {10.1007/11535218_32},
volume = {3621},
year = {2005},
}