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A survey of freeform object representation and recognition techniques
 Computer Vision and Image Understanding
, 2001
"... Advances in computer speed, memory capacity, and hardware graphics acceleration have made the interactive manipulation and visualization of complex, detailed (and therefore large) threedimensional models feasible. These models are either painstakingly designed through an elaborate CAD process or re ..."
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Cited by 200 (1 self)
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Advances in computer speed, memory capacity, and hardware graphics acceleration have made the interactive manipulation and visualization of complex, detailed (and therefore large) threedimensional models feasible. These models are either painstakingly designed through an elaborate CAD process or reverse engineered from sculpted prototypes using modern scanning technologies and integration methods. The availability of detailed data describing the shape of an object offers the computer vision practitioner new ways to recognize and localize freeform objects. This survey reviews recent literature on both the 3D model building process and techniques used to match and identify freeform objects from imagery. c ○ 2001 Academic Press 1.
COSMOS  A Representation Scheme for 3D FreeForm Objects
 IEEE Transactions on Pattern Analysis and Machine Intelligence
, 1995
"... We address the problem of representing and recognizing 3D freeform objects when (a) the object viewpoint is arbitrary, (b) the objects may vary in shape and complexity, and (c) no restrictive assumptions are made about the types of surfaces on the object. We assume that a range image of a scene is ..."
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Cited by 82 (2 self)
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We address the problem of representing and recognizing 3D freeform objects when (a) the object viewpoint is arbitrary, (b) the objects may vary in shape and complexity, and (c) no restrictive assumptions are made about the types of surfaces on the object. We assume that a range image of a scene is available, containing a view of a rigid 3D object without occlusion. We propose a new and general surface representation scheme for recognizing objects with freeform (sculpted) surfaces. In this scheme, an object is described concisely in terms of maximal surface patches of constant shape index. The maximal patches that represent the object are mapped onto the unit sphere via their orientations, and aggregated via shape spectral functions. Properties such as surface area, curvedness and connectivity which are required to capture local and global information are also built into the representation. The scheme yields a meaningful and rich description useful for object recognition. A novel conce...
The 3L Algorithm for Fitting Implicit Polynomial Curves and Surfaces to Data
 IEEE Transactions on Pattern Analysis and Machine Intelligence
, 2000
"... Of great importance to a wide variety of computer vision and image analysis problems is the ability to represent two (2D) and threedimensional (3D) data or objects. Implicit polynomial curves and surfaces are two of the most useful representations available. Their representational power is evidenc ..."
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Cited by 54 (4 self)
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Of great importance to a wide variety of computer vision and image analysis problems is the ability to represent two (2D) and threedimensional (3D) data or objects. Implicit polynomial curves and surfaces are two of the most useful representations available. Their representational power is evidenced by their ability to smooth noisy data and to interpolate through sparse or missing data. Furthermore, their associated Euclidean and affine invariants are powerful discriminators, making implicit polynomials a computationally attractive technology for recognizing objects in arbitrary positions with respect to cameras or range sensors. In this paper, we introduce a completely new approach to fitting implicit polynomials to data. The algorithm represents a significant advancement of implicit polynomial technology for three important reasons. First, it is orders of magnitude faster than existing methods. Second, it has significantly better repeatability and numerical stability than current m...
Improving The Stability Of Algebraic Curves For Applications
 IEEE Trans. on Image Proc
, 2000
"... An algebraic curve is defined as the zero set of a polynomial in two variables. Algebraic curves are practical for modeling shapes much more complicated than conics or superquadrics. The main drawback in representing shapes by algebraic curves has been the lack of repeatability in fitting algebraic ..."
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Cited by 42 (5 self)
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An algebraic curve is defined as the zero set of a polynomial in two variables. Algebraic curves are practical for modeling shapes much more complicated than conics or superquadrics. The main drawback in representing shapes by algebraic curves has been the lack of repeatability in fitting algebraic curves to data. Usually, arguments against using algebraic curves involve references to mathematicians Wilkinson (see [1] chapter 7) and Runge (see [3] chapter 4). The first goal of this article is to understand the stability issue of algebraic curve tting. Then a fitting method based on ridge regression and restricting the representation to well behaved subsets of polynomials is proposed, and its properties are investigated. The fitting algorithm is of sufficient stability for very fast positioninvariant shape recognition, position estimation, and shape tracking, based on invariants and new representations. Among appropriate applications are shapebased indexing into image databases.
3L Fitting of Higher Degree Implicit Polynomials”,
 Proceedings of Third IEEE Workshop on Applications of Computer Vision,
, 1996
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3D Shapebased Face Recognition using Automatically Registered Facial Surfaces
, 2004
"... In this paper, we address the use of three dimensional facial shape information for human face identification. We propose a new method to represent faces as 3D registered point clouds. Fine registration of facial surfaces is done by first automatically finding important facial landmarks and then, es ..."
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Cited by 28 (9 self)
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In this paper, we address the use of three dimensional facial shape information for human face identification. We propose a new method to represent faces as 3D registered point clouds. Fine registration of facial surfaces is done by first automatically finding important facial landmarks and then, establishing a dense correspondence between points on the facial surface with the help of a 3D face template aided thin plate spline algorithm. After the registration of facial surfaces, similarity between two faces is defined as a discrete approximation of the volume difference between facial surfaces. Experiments done on the 3D RMA dataset show that the proposed algorithm performs as good as the point signature method, and it is statistically superior to the point distribution modelbased method and the 2D depth imagery technique. In terms of computational complexity, the proposed algorithm is faster than the point signature method.
3D Object Recognition Using Shape SimiliarityBased Aspect Graph
"... We present an aspectgraph approach to 3D object recognition where the definition of an aspect is motivated by its role in the subsequent recognition step. Specifically, we measure the similarity between two views by a 2D shape metric of similarity measuring the distance between the projected, segme ..."
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Cited by 24 (0 self)
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We present an aspectgraph approach to 3D object recognition where the definition of an aspect is motivated by its role in the subsequent recognition step. Specifically, we measure the similarity between two views by a 2D shape metric of similarity measuring the distance between the projected, segmented shapes of the 3D object. This endows the viewing sphere with a metric which is used to group similar views into aspects, and to represent each aspect by a prototype. The same shape similarity metric is then used to rate the similarity between unknown views of unknown objects and stored prototypes to identify the object and its pose. The performance of this approach on a database of 18 objects each viewed in five degree increments along the ground viewing plane is demonstrated. 1
Reconstruction of threedimensional objects through matching of their parts
 IEEE TRANS. PAMI
, 2002
"... The problem of reassembling an object from its parts or fragments has never been addressed with a unified computational approach, which depends on the pure geometric form of the parts and not applicationspecific features. We propose a method for the automatic reconstruction of a model based on th ..."
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Cited by 23 (6 self)
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The problem of reassembling an object from its parts or fragments has never been addressed with a unified computational approach, which depends on the pure geometric form of the parts and not applicationspecific features. We propose a method for the automatic reconstruction of a model based on the geometry of its parts, which may be computergenerated models or rangescanned models. The matching process can benefit from any other external constraint imposed by the specific application.
Active Recognition: Using Uncertainty to Reduce Ambiguity
 IN PROCEEDINGS OF THE 13TH INTERNATIONAL CONFERENCE ON PATTERN RECOGNITION
, 1996
"... Ambiguity in scene information, due to noisy measurements and uncertain object models, can be quantified and actively used by an autonomous agent to efficiently gather new data and improve its information about the environment. In this work an informationbased utility measure is used to derive from ..."
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Cited by 19 (2 self)
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Ambiguity in scene information, due to noisy measurements and uncertain object models, can be quantified and actively used by an autonomous agent to efficiently gather new data and improve its information about the environment. In this work an informationbased utility measure is used to derive from a learned classification of shape models an efficient data collection strategy, specifically aimed at increasing classification confidence when recognizing uncertain shapes. Promising experimental results are reported.
A New Bayesian Framework for Object Recognition
 In IEEE Conference on Computer Vision and Pattern Recognition
, 1998
"... We describe a new approach to featurebased object recognition, using maximum a posteriori (MAP) estimation under a Markov random field (MRF) model. The main advantage of this approach is that it allows explicit modeling of dependencies between individual features of an object model. For instance, i ..."
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Cited by 17 (2 self)
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We describe a new approach to featurebased object recognition, using maximum a posteriori (MAP) estimation under a Markov random field (MRF) model. The main advantage of this approach is that it allows explicit modeling of dependencies between individual features of an object model. For instance, it can capture the fact that unmatched features due to partial occlusion are generally spatially coherent rather than independent. Efficient computation of the MAP estimate in our framework can be accomplished by finding a minimum cut on an appropriately defined graph. A special case of our framework yields even more efficient method, that does not use graph cuts. We call this technique spatially coherent matching. Our framework can also be seen as providing a probabilistic understanding of Hausdorff matching. We present ROC curves from Monte Carlo experiments that illustrate the improvement of the new spatially coherent matching technique over Hausdorff matching. 1 Introduction In this pap...