The basic idea of calibrating a camera system in previous approaches is to determine camera parameters by using a set of known 3D points as calibration reference.In this paper,we present a method of camera calibration...The basic idea of calibrating a camera system in previous approaches is to determine camera parameters by using a set of known 3D points as calibration reference.In this paper,we present a method of camera calibration in which camera parameters are determined by a set of 3D lines.A set of constraints is derived on camera parameters in terms of perspective line mapping.From these con- straints,the same perspective transformation matrix as that for point mapping can be computed linearly.The minimum number of calibration lines is 6.This result generalizes that of Lin,Huang and Faugeras for camera location determination in which at least 8 line correspondences are re- quired for linear computation of camera location.Since line segments in an image can be located easi- ly and more accurately than points,the use of lines as calibration reference tends to ease the compu- tation in image preprocessing and to improve calibration accuracy.Experimental results on the calibration along with stereo reconstruction are reported.展开更多
This paper presents a robust image feature that can be used to automatically establish match correspondences between aerial images of suburban areas with large view variations. Unlike most commonly used invariant imag...This paper presents a robust image feature that can be used to automatically establish match correspondences between aerial images of suburban areas with large view variations. Unlike most commonly used invariant image features, this feature is view variant. The geometrical structure of the feature allows predicting its visual appearance according to the observer’s view. This feature is named 2EC (2 Edges and a Corner) as it utilizes two line segments or edges and their intersection or corner. These lines are constrained to correspond to the boundaries of rooftops. The description of each feature includes the two edges’ length, their intersection, orientation, and the image patch surrounded by a parallelogram that is constructed with the two edges. Potential match candidates are obtained by comparing features, while accounting for the geometrical changes that are expected due to large view variation. Once the putative matches are obtained, the outliers are filtered out using a projective matrix optimization method. Based on the results of the optimization process, a second round of matching is conducted within a more confined search space that leads to a more accurate match establishment. We demonstrate how establishing match correspondences using these features lead to computing more accurate camera parameters and fundamental matrix and therefore more accurate image registration and 3D reconstruction.展开更多
In the paper,we define weakly δ-continuous correspondences on super-space,On the basis of δ-open(closed) sets,θ-open(closed) sets and regular open(closed) sets in topological space,some equivalent conditions of thi...In the paper,we define weakly δ-continuous correspondences on super-space,On the basis of δ-open(closed) sets,θ-open(closed) sets and regular open(closed) sets in topological space,some equivalent conditions of this kind of correspondences are obtained,and some applications of subset nets and convergence nets are given.展开更多
A much debated issue in linguistics involves the extent to which the forms of languages(phonemes,morphemes,words,phrases and syntactic structures)have been shaped by the functions that languages perform.This paper beg...A much debated issue in linguistics involves the extent to which the forms of languages(phonemes,morphemes,words,phrases and syntactic structures)have been shaped by the functions that languages perform.This paper begins by defining what these"functions"are:the forms of language must express(i.e.be capable of being paired with)an infinite set of meanings in a consistent way;these form-meaning pairings must be readily processable by language producers and comprehenders in real time;and they must be readily learnable.This paper then focuses on the processability function,and enumerates some problems that complicate discussions of whether processing has actually played a role in shaping grammars,especially in morphology and syntax.Most of these problems,it is argued,are the result of unresolved issues in current theories regarding e.g.the precise relationship between production and comprehension,the measurement of working memory load,and the relationship between prediction and the integration of preceding and following items in on-line processing.I argue here that the linguistic question of explaining why the world’s grammars are the way they are,and understanding the role of processing in explaining grammatical forms,need not,and cannot,wait for these big general issues to be resolved in psycholinguistics.Instead,we can adopt a more empirical approach that compares patterns in grammatical forms and structures across languages with relevant empirical patterns in usage data within languages,from corpora and experiments.This more empirical approach allows us to test whether there is,or is not,a match between grammatical data on the one hand,and usage data on the other,that are the products of the processing mechanisms that psycholinguistic theories are trying to def ine.These patterns can be described in theory-general or-neutral ways and they can shed light on whether grammatical forms have been shaped by performance,without us having to f ill in all the details of the contributing processing theories.This paper il展开更多
For the past three decades, interoperability among heterogeneous systems had been a hard nut to crack due to the schematic and semantic perspectives that exist between objects. These systems were built under different...For the past three decades, interoperability among heterogeneous systems had been a hard nut to crack due to the schematic and semantic perspectives that exist between objects. These systems were built under different data models. As such, levels of the local schemas are semantically very poor due to the limited expressiveness of traditional data models in which they were designed. Further more, most of the existing schema integration architectural components are inadequately equipped to handle the mapping schemas, especially when the semantics and structural conflicts are involved. This paper introduces an Intelligent Binary Schema Matching system (IBSMS), which exploits the phenomenon of making its components intelligent. That’s equipping its components such as translators and integrators with adequate knowledge about various data models. This allows the components acquire enough intelligence to maneuver or manipulate the correspondence between constructs from different models. In addition, the system has a Binary Matcher, which compares the attribute correspondences of various databases in a pairwise form, in order to establish the equivalences. With the establishment of the mappings, the users shall be able to access them (mappings) for their desired usage.展开更多
In this paper,a new method is presented for 3D motion estimation by image region correspon- dences using stereo cameras.Under the weak perspectivity assumption,we first employ the moment tensor theory(Cyganski and Orr...In this paper,a new method is presented for 3D motion estimation by image region correspon- dences using stereo cameras.Under the weak perspectivity assumption,we first employ the moment tensor theory(Cyganski and Orr)to compute the monocular affine transformations relating images taken by the same camera at different time instants and the binocular affine transformations relating images taken by different cameras at the same time instant.We then show that 3D motion can he recovered from these 2D transformations.A space-time fusion strategy is proposed to aim at robust results.No knowledge of point correspondences is required in the above processes and the computa- lions involved are linear.To find corresponding image regions,new affine invariants,which show stronger invariance,are derived in term of tensor contraction theory.Experiments on real motion images are conducted to verify the proposed method.展开更多
文摘The basic idea of calibrating a camera system in previous approaches is to determine camera parameters by using a set of known 3D points as calibration reference.In this paper,we present a method of camera calibration in which camera parameters are determined by a set of 3D lines.A set of constraints is derived on camera parameters in terms of perspective line mapping.From these con- straints,the same perspective transformation matrix as that for point mapping can be computed linearly.The minimum number of calibration lines is 6.This result generalizes that of Lin,Huang and Faugeras for camera location determination in which at least 8 line correspondences are re- quired for linear computation of camera location.Since line segments in an image can be located easi- ly and more accurately than points,the use of lines as calibration reference tends to ease the compu- tation in image preprocessing and to improve calibration accuracy.Experimental results on the calibration along with stereo reconstruction are reported.
文摘This paper presents a robust image feature that can be used to automatically establish match correspondences between aerial images of suburban areas with large view variations. Unlike most commonly used invariant image features, this feature is view variant. The geometrical structure of the feature allows predicting its visual appearance according to the observer’s view. This feature is named 2EC (2 Edges and a Corner) as it utilizes two line segments or edges and their intersection or corner. These lines are constrained to correspond to the boundaries of rooftops. The description of each feature includes the two edges’ length, their intersection, orientation, and the image patch surrounded by a parallelogram that is constructed with the two edges. Potential match candidates are obtained by comparing features, while accounting for the geometrical changes that are expected due to large view variation. Once the putative matches are obtained, the outliers are filtered out using a projective matrix optimization method. Based on the results of the optimization process, a second round of matching is conducted within a more confined search space that leads to a more accurate match establishment. We demonstrate how establishing match correspondences using these features lead to computing more accurate camera parameters and fundamental matrix and therefore more accurate image registration and 3D reconstruction.
文摘In the paper,we define weakly δ-continuous correspondences on super-space,On the basis of δ-open(closed) sets,θ-open(closed) sets and regular open(closed) sets in topological space,some equivalent conditions of this kind of correspondences are obtained,and some applications of subset nets and convergence nets are given.
文摘A much debated issue in linguistics involves the extent to which the forms of languages(phonemes,morphemes,words,phrases and syntactic structures)have been shaped by the functions that languages perform.This paper begins by defining what these"functions"are:the forms of language must express(i.e.be capable of being paired with)an infinite set of meanings in a consistent way;these form-meaning pairings must be readily processable by language producers and comprehenders in real time;and they must be readily learnable.This paper then focuses on the processability function,and enumerates some problems that complicate discussions of whether processing has actually played a role in shaping grammars,especially in morphology and syntax.Most of these problems,it is argued,are the result of unresolved issues in current theories regarding e.g.the precise relationship between production and comprehension,the measurement of working memory load,and the relationship between prediction and the integration of preceding and following items in on-line processing.I argue here that the linguistic question of explaining why the world’s grammars are the way they are,and understanding the role of processing in explaining grammatical forms,need not,and cannot,wait for these big general issues to be resolved in psycholinguistics.Instead,we can adopt a more empirical approach that compares patterns in grammatical forms and structures across languages with relevant empirical patterns in usage data within languages,from corpora and experiments.This more empirical approach allows us to test whether there is,or is not,a match between grammatical data on the one hand,and usage data on the other,that are the products of the processing mechanisms that psycholinguistic theories are trying to def ine.These patterns can be described in theory-general or-neutral ways and they can shed light on whether grammatical forms have been shaped by performance,without us having to f ill in all the details of the contributing processing theories.This paper il
文摘For the past three decades, interoperability among heterogeneous systems had been a hard nut to crack due to the schematic and semantic perspectives that exist between objects. These systems were built under different data models. As such, levels of the local schemas are semantically very poor due to the limited expressiveness of traditional data models in which they were designed. Further more, most of the existing schema integration architectural components are inadequately equipped to handle the mapping schemas, especially when the semantics and structural conflicts are involved. This paper introduces an Intelligent Binary Schema Matching system (IBSMS), which exploits the phenomenon of making its components intelligent. That’s equipping its components such as translators and integrators with adequate knowledge about various data models. This allows the components acquire enough intelligence to maneuver or manipulate the correspondence between constructs from different models. In addition, the system has a Binary Matcher, which compares the attribute correspondences of various databases in a pairwise form, in order to establish the equivalences. With the establishment of the mappings, the users shall be able to access them (mappings) for their desired usage.
文摘In this paper,a new method is presented for 3D motion estimation by image region correspon- dences using stereo cameras.Under the weak perspectivity assumption,we first employ the moment tensor theory(Cyganski and Orr)to compute the monocular affine transformations relating images taken by the same camera at different time instants and the binocular affine transformations relating images taken by different cameras at the same time instant.We then show that 3D motion can he recovered from these 2D transformations.A space-time fusion strategy is proposed to aim at robust results.No knowledge of point correspondences is required in the above processes and the computa- lions involved are linear.To find corresponding image regions,new affine invariants,which show stronger invariance,are derived in term of tensor contraction theory.Experiments on real motion images are conducted to verify the proposed method.
