13849872
As-consistent-As-possible compositing of virtual objects and video sequences
We present an efficient approach that merges the virtual objects into video sequences taken by a freely moving camera in a realistic manner. The composition is visually and geometrically consistent through three main steps. First, a robust camera tracking algorithm based on key frames is proposed, which precisely recovers the focal length with a novel multi-frame strategy. Next, the concerned 3D models of the real scenes are reconstructed by means of an extended multi-baseline algorithm. Finally, the virtual objects in the form of 3D models are integrated into the real scenes, with special cares on the interaction consistency including shadow casting, occlusions, and object animation. A variety of experiments have been implemented, which demonstrate the robustness and efficiency of our approach. Copyright © 2006 John Wiley & Sons, Ltd.
7914535
Stereoscopic Video Synthesis from a Monocular Video
This paper presents an automatic and robust approach to synthesize stereoscopic videos from ordinary monocular videos acquired by commodity video cameras. Instead of recovering the depth map, the proposed method synthesizes the binocular parallax in stereoscopic video directly from the motion parallax in monocular video, The synthesis is formulated as an optimization problem via introducing a cost function of the stereoscopic effects, the similarity, and the smoothness constraints. The optimization selects the most suitable frames in the input video for generating the stereoscopic video frames. With the optimized selection, convincing and smooth stereoscopic video can be synthesized even by simple constant-depth warping. No user interaction is required. We demonstrate the visually plausible results obtained given the input clips acquired by ordinary handheld video camera.
29934128
A Representation of SFP
This chapter introduces a representation of the category of SFP domains. It uses structures similar to but more general than Scott’s information systems. Distilled from Gentzen’s sequent calculi, a basic structure called a sequent structure is produced. Sequent structures determine a major part of the axioms of information systems. A category of special kind of sequent structures called the strongly finite ones is shown to be equivalent to the category of SFP domains. Constructions like the Plotkin power domain and the function space are given, as well as a complete partial order of such structures to give solutions to recursively defined systems.
2739680
Domain Theory Meets Default Logic
We present a development of the theory of default information structures, combining ideas from domain theory with ideas from non-monotonic logic. Conceptually, our treatment is distinguished from standard default logic in that we view default structures as generating models rather than theories. Reiter's default rules are viewed as non-deterministic algorithms for generating preferred partial models. Using domain-theoretical notions, we improve the standard de nition of extensions in default logic, by introducing the notion of dilation. We prove the existence of such dilations for a new, natural class of default information structures, properly including the so-called semi-normal ones. This class, called the class of rational structures, is a robust generalization of the usual kind of default rule system.
39256502
Bifinite Chu Spaces
This paper studies colimits of sequences of finite Chu spaces and their ramifications. We consider three base categories of Chu spaces: the generic Chu spaces (C), the extensional Chu spaces (E), and the biextensional Chu spaces (B). The main results are: (1) a characterization of monics in each of the three categories; (2) existence (or the lack thereof) of colimits and a characterization of finite objects in each of the corresponding categories using monomorphisms/injections (denoted as iC, iE, and iB, respectively); (3) a formulation of bifinite Chu spaces with respect to iC; (4) the existence of universal, homogeneous Chu spaces in this category. Unanticipated results driving this development include the fact that: (a) in C, a morphism (f, g) is monic iff f is injective and g is surjective while for E and B, (f, g) is monic iff f is injective (but g is not necessarily surjective); (b) while colimits always exist in iE, it is not the case for iC and iB; (c) not all finite Chu spaces (considered set-theoretically) are finite objects in their categories. This study opens up opportunities for further investigations into recursively defined Chu spaces, as well as constructive models of linear logic.
36095353
Extremal Regular Graphs with Prescribed Odd Girth
The odd girth of a graph G gives the length of a shortest odd cycle in G. Let ?(k, g) denote the smallest n such that there exists a k-regular graph of order n and odd girth g. It is known that ?(k, g) ? kg/2 and that ?(k, g) = kg/2 if k is even. The exact values of ?(k, g) are also known if k = 3 or g = 5. Let ?x?e denote the smallest even integer no less than x, ?(g) = (?1)g ? 1/2, and s(k) = min {p + q | k = pq, where p and q are both positive integers}. It is proved that if k ? 5 and g ? 7 are both odd, then formula] with the exception that ?(5, 7) = 20.
30701744
Single change covering designs
A single-change covering designSC (v, k, b) on av-setV is a sequence ofb k-sets (blocks) onV which together cover every pair of elements ofV at least once, such that two successive blocks havek−1 elements in common. It is desirable to minimizeb. Some constructions and lower bounds forb are given.