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The rapid recovery of three-dimensional structure from line drawings Rensink, Ronald Andy
Abstract
A computational theory is developed that explains how line drawings of polyhedral objects can be interpreted rapidly and in parallel at early levels of human vision. The key idea is that a time-limited process can correctly recover much of the three-dimensional structure of these objects when split into concurrent streams, each concerned with a single aspect of scene structure. The work proceeds in five stages. The first extends the framework of Marr to allow a process to be analyzed in terms of resource limitations. Two main concerns are identified: (i) reducing the amount of nonlocal information needed, and (ii) making effective use of whatever information is obtained. The second stage traces the difficulty of line interpretation to a small set of constraints. When these are removed, the remaining constraints can be grouped into several relatively independent sets. It is shown that each set can be rapidly solved by a separate processing stream, and that co-ordinating these streams can yield a low-complexity "approximation" that captures much of the structure of the original constraints. In particular, complete recovery is possible in logarithmic time when objects have rectangular corners and the scene-to-image projection is orthographic. The third stage is concerned with making good use of the available information when a fixed time limit exists. This limit is motivated by the need to obtain results within a time independent of image content, and by the need to limit the propagation of inconsistencies. A minimal architecture is assumed, viz., a spatiotopic mesh of simple processors. Constraints are developed to guide the course of the process itself, so that candidate interpretations are considered in order of their likelihood. The fourth stage provides a specific algorithm for the recovery process, showing how it can be implemented on a cellular automaton. Finally, the theory itself is tested on various line drawings. It is shown that much of the three-dimensional structure of a polyhedral scene can indeed be recovered in very little time. It also is shown that the theory can explain the rapid interpretation of line drawings at early levels of human vision.
Item Metadata
Title |
The rapid recovery of three-dimensional structure from line drawings
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1992
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Description |
A computational theory is developed that explains how line drawings of polyhedral objects
can be interpreted rapidly and in parallel at early levels of human vision. The key idea is
that a time-limited process can correctly recover much of the three-dimensional structure of
these objects when split into concurrent streams, each concerned with a single aspect of scene
structure.
The work proceeds in five stages. The first extends the framework of Marr to allow a
process to be analyzed in terms of resource limitations. Two main concerns are identified:
(i) reducing the amount of nonlocal information needed, and (ii) making effective use of
whatever information is obtained. The second stage traces the difficulty of line interpretation
to a small set of constraints. When these are removed, the remaining constraints can be
grouped into several relatively independent sets. It is shown that each set can be rapidly
solved by a separate processing stream, and that co-ordinating these streams can yield a low-complexity
"approximation" that captures much of the structure of the original constraints.
In particular, complete recovery is possible in logarithmic time when objects have rectangular
corners and the scene-to-image projection is orthographic. The third stage is concerned with
making good use of the available information when a fixed time limit exists. This limit is
motivated by the need to obtain results within a time independent of image content, and by
the need to limit the propagation of inconsistencies. A minimal architecture is assumed, viz.,
a spatiotopic mesh of simple processors. Constraints are developed to guide the course of the
process itself, so that candidate interpretations are considered in order of their likelihood.
The fourth stage provides a specific algorithm for the recovery process, showing how it can
be implemented on a cellular automaton. Finally, the theory itself is tested on various line
drawings. It is shown that much of the three-dimensional structure of a polyhedral scene can
indeed be recovered in very little time. It also is shown that the theory can explain the rapid
interpretation of line drawings at early levels of human vision.
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Extent |
10129176 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2008-12-17
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0051339
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
1992-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.