Dynamic distance-based shape features for gait recognition

We propose a novel skeleton-based approach to gait recognition using our Skeleton Variance Image. The core of our approach consists of employing the screened Poisson equation to construct a family of smooth distance functions associated with a given shape. The screened Poisson distance function approximation nicely absorbs and is relatively stable to shape boundary perturbations which allows us to define a rough shape skeleton. We demonstrate how our Skeleton Variance Image is a powerful gait cycle descriptor leading to a significant improvement over the existing state of the art gait recognition rate

On covariate factor detection and removal for robust gait recognition

We propose a novel bolt-on model capable of boostingthe robustness of various single compact 2D gait representations.Gait recognition is negatively influenced by covariatefactors including clothing and time which alter thenatural gait appearance and motion. Contrary to traditionalgait recognition, our bolt-on module remedies this by a dedicatedcovariate factor detection and removal procedure whichwe quantitatively and qualitatively evaluate. The fundamentalconcept of the bolt-on module is founded on exploitingthe pixel-wise composition of covariates factors. Resultsdemonstrate how our bolt-on module is a powerful componentleading to significant improvements across gait representationsand datasets yielding state of the art results

Permanents, Pfaffian orientations, and even directed circuits

Given a 0-1 square matrix A, when can some of the 1's be changed to -1's in such a way that the permanent of A equals the determinant of the modified matrix? When does a real square matrix have the property that every real matrix with the same sign pattern (that is, the corresponding entries either have the same sign or are both zero) is nonsingular? When is a hypergraph with n vertices and n hyperedges minimally nonbipartite? When does a bipartite graph have a "Pfaffian orientation"? Given a digraph, does it have no directed circuit of even length? Given a digraph, does it have a subdivision with no even directed circuit? It is known that all of the above problems are equivalent. We prove a structural characterization of the feasible instances, which implies a polynomial-time algorithm to solve all of the above problems. The structural characterization says, roughly speaking, that a bipartite graph has a Pfaffian orientation if and only if it can be obtained by piecing together (in a specified way) planar bipartite graphs and one sporadic nonplanar bipartite graph.Comment: 47 pages, published versio