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Outline H. Murase, and S. K. Nayar, “Visual learning and recognition of 3-D objects from appearance,” International Journal of Computer Vision, vol. 14, pp. 5-24, 1995.
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Basic Ideas Each 3-D object of interest is represented by views under different poses and illuminations (possibly other conditions) The view, or the appearance of a 3-D object depends on the object’s shape, reflectance properties, pose (viewing angle), and the illumination conditions (lighting conditions) December 9, 2018 Computer Vision
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One Example December 9, 2018 Computer Vision
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Parametric Manifolds All the possible images of a 3-D object under different view angles form a curve in a high dimensional image space December 9, 2018 Computer Vision
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Parametric Manifolds December 9, 2018 Computer Vision
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Parametric Manifolds If we change the view angle and the lighting conditions, all the images of a 3-D object form a 2-D manifold in the high dimensional image space December 9, 2018 Computer Vision
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Parametric Manifolds December 9, 2018 Computer Vision
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Parametric Manifolds December 9, 2018 Computer Vision
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Parametric Manifolds December 9, 2018 Computer Vision
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Parametric Manifolds December 9, 2018 Computer Vision
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Recognition and Pose Estimation
The recognition is achieved by finding the manifold that has the minimum distance to the input image, which is done by December 9, 2018 Computer Vision
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Recognition and Pose Estimation
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Computational Issues Since the images are of high dimensional, it is computationally expensive to perform the minimization The solution is to perform dimension reduction using principal component analysis December 9, 2018 Computer Vision
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Image Sets Each object has an image set The universal image set
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Computing Eigenspace For the universal set, we first compute the average of all of the images Then we form a new set by subtracting the average from all the images Then we compute the covariance matrix We obtain eigenvectors and corresponding eigenvalues December 9, 2018 Computer Vision
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How Many Eigenvectors to Use?
One way to select the first k eigenvectors with largest eigenvalues to capture appearance variations in the image set December 9, 2018 Computer Vision
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More Efficient to Compute Eigenspace
When the number of images is much smaller than the dimension of an image, we can compute the eigenvectors and eigenvalues more efficiently December 9, 2018 Computer Vision
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Parametric Eigenspace Representation
After we compute the eigenvectors, we project all the images by The representations of an object should form a manifold Which is approximated using a standard cubic-spline interpolation algorithm December 9, 2018 Computer Vision
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Object’s Eigenspace Similarly, we can compute eigenvectors and representations of images of an object using its image set only December 9, 2018 Computer Vision
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More Efficient Recognition and Pose Estimation
The recognition is done in the universal eigenspace The pose estimation is done in the object specific eigenspace December 9, 2018 Computer Vision
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Recognition and Pose Estimation Results for Object Set 1
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Real-Time Recognition System
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Real-Time Recognition System
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Real-Time Recognition System
December 9, 2018 Computer Vision
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