The major direct solutions to the three-point perspective pose estimation problems are reviewed from a unified perspective. The numerical stability of these three-point perspective solutions are discussed. It is shown...
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ISBN:
(纸本)0818621486
The major direct solutions to the three-point perspective pose estimation problems are reviewed from a unified perspective. The numerical stability of these three-point perspective solutions are discussed. It is shown that even in cases where the solution is not near the geometric unstable region considerable care must be exercised in the calculation. Depending on the order of the substitutions utilized, the relative error can change over a thousand to one. This difference is due entirely to the way the calculations are performed and not to any geometric structural instability of any problem instance. An analytical method is presented which produces a numerically stable calculation.
A unified theoretical framework for motion transparency and motion boundaries by devising fundamental constraint equations of multiple optical flow is proposed. This framework can handle flow discontinuities at motion...
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ISBN:
(纸本)0818621486
A unified theoretical framework for motion transparency and motion boundaries by devising fundamental constraint equations of multiple optical flow is proposed. This framework can handle flow discontinuities at motion boundaries as well as flow multiplicities due to transparency of objects in a unified manner. The constraint equations are formulated by a composition of homogeneously parametrized differential operators on the space-time image. Fitting algorithms for the constraints which result in eigensystem analyses are described. To determine the number of flows, the authors use the margin energy, a measure of goodness of fit which is the difference between the first and the second lower eigenenergy of the eigensystem. They also hypothesize a criterion for multiplicity. The measure and the criterion are derived from the analogy of quantum mechanics. It is demonstrated that the margin energy can determine the transparency and discontinuities of the flow field as regions of more than one flow.
This conference proceedings contains 147 papers. The following topic are dealt with: object recognition;stereo and surface reconstruction;calibration;motion;low level vision--edge detection;optical flow;non-rigid moti...
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ISBN:
(纸本)0818621486
This conference proceedings contains 147 papers. The following topic are dealt with: object recognition;stereo and surface reconstruction;calibration;motion;low level vision--edge detection;optical flow;non-rigid motion;texture;active vision and perceptual grouping;patternrecognition and segmentation;architecture and algorithms;shape from shading;pose estimation and face recognition;depth.
An 'aura' framework is used to rewrite the nonlinear energy function of a homogeneous anisotropic Markov/Gibbs random field (MRF) as a linear sum of aura measures. The formulation relates MRFs to co-occurrence...
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ISBN:
(纸本)0818621486
An 'aura' framework is used to rewrite the nonlinear energy function of a homogeneous anisotropic Markov/Gibbs random field (MRF) as a linear sum of aura measures. The formulation relates MRFs to co-occurrence matrices. It also provides a physical interpretation of MRF textures in terms of the mixing and separation of gray-level sets, and in terms of boundary maximization and minimization. Within this framework, the authors introduce the use of temperature for texture modeling and show how the parameters of the MRF can be interpreted as temperature annealing rates. In particular, they show evidence for a transition temperature, above which all patterns generated will be visually similar, and below which a pattern evolves down to its ground state. Results which characterize the ground state patterns are described.
A direct method called fixation is introduced for solving the general motion vision problem, arbitrary motion relative to an arbitrary rigid scene. This method results in a linear constraint equation which explicitly ...
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ISBN:
(纸本)0818621486
A direct method called fixation is introduced for solving the general motion vision problem, arbitrary motion relative to an arbitrary rigid scene. This method results in a linear constraint equation which explicitly expresses rotational velocity in terms of translational velocity. By combining this constraint equation with the brightness-change constraint equation, general solutions are found for translational and rotational velocities, and the shape. Avoiding correspondence and optical flow has been the motivation behind this direct method, which uses the brightness gradients directly. Partial implementation of the fixation method on real images has shown encouraging results which support some of the presented algorithms.
A generic polyhedral model is represented as a network of nodes and constraints. Nodes are 3-D vectors representing the location and orientation of the geometric entities, or measure variables such as length or cosine...
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ISBN:
(纸本)0818621486
A generic polyhedral model is represented as a network of nodes and constraints. Nodes are 3-D vectors representing the location and orientation of the geometric entities, or measure variables such as length or cosine. Constraints are polynomial equations in the node parameters. Modeling and recognition are viewed as solving for values of the node parameters such that all the constraint equations are satisfied and the mean square error between the model and the observed shape is minimized. Buchberger's Grobner basis algorithm and Ritt-Wu's triangulation algorithm can be used for eliminating dependent parameters as well as for detecting inconsistency among constraints. Numerical techniques are used to find the best-fit model subject to constraints.
A method for recovering shape from shading that solves directly for the surface height is presented. By using a discrete formulation of the problem, it is possible to achieve good convergence behavior by employing num...
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ISBN:
(纸本)0818621486
A method for recovering shape from shading that solves directly for the surface height is presented. By using a discrete formulation of the problem, it is possible to achieve good convergence behavior by employing numerical solution techniques more powerful than gradient descent methods derived from variational calculus. Because this method solves directly for height, it avoids the problem of finding an integrable surface maximally consistent with surface orientation. Furthermore, since additional constraints are not needed to make the problem well posed, a smoothness constraint is used only to drive the system towards a good solution;the weight of the smoothness term is eventually reduced to near zero. By solving directly for height, stereo processing may be used to provide initial and boundary conditions. The shape from shading technique, as well as its relation to stereo, is demonstrated on both synthetic and real imagery.
A closed-loop image segmentation system that incorporates a genetic algorithm to adapt the segmentation process to changes in image characteristics caused by variable environmental conditions is presented. The genetic...
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ISBN:
(纸本)0818621486
A closed-loop image segmentation system that incorporates a genetic algorithm to adapt the segmentation process to changes in image characteristics caused by variable environmental conditions is presented. The genetic algorithm efficiently searches the hyperspace of segmentation parameter combinations to determine the parameter set which maximizes the segmentation quality criteria. A summary of the experimental results that demonstrates the ability to perform adaptive image segmentation and to learn from experience using a collection of outdoor color imagery is given.
An algorithm that identifies inter-reflection by using chromatic information in color images is presented. Several experimental results from test images show that the proposed method could play the role of an added en...
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ISBN:
(纸本)0818621486
An algorithm that identifies inter-reflection by using chromatic information in color images is presented. Several experimental results from test images show that the proposed method could play the role of an added enhancement stage in the segmentation method using the dichromatic reflection model, and could be an independent identification scheme by itself. The algorithm does not consider multiple bounces of light and deals with body-to-body interreflection only. This model must be combined with other intrinsic models of surface properties such as metals which exhibit strong surface reflection but not body reflection.
An approach which allows an arbitrary structure estimation to be embedded into a recursive estimation process that incrementally improves a structure estimate with every new frame that becomes available is discussed. ...
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ISBN:
(纸本)0818621486
An approach which allows an arbitrary structure estimation to be embedded into a recursive estimation process that incrementally improves a structure estimate with every new frame that becomes available is discussed. The approach is based on Bayesian estimation theory and the Kalman filter. The authors demonstrate how it may be applied to such domains as depth from motion and depth from shading.
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