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Creating Generative Models from Range Images


Ramamoorthi, Ravi (1998) Creating Generative Models from Range Images. Master's thesis, California Institute of Technology. doi:10.7907/VZXG-Q639.


We describe a new approach for creating concise high-level generative models from one or more approximate range images. Using simple acquisition techniques and a user-defined class of models, our method produces a simple and intuitive object description that is relatively insensitive to noise and is easy to manipulate and edit. The algorithm has two inter-related phases—recognition, which chooses an appropriate model within a given hierarchy, and parameter estimation, which adjusts the model to fit the data. We give a simple method for automatically making tradeoffs between simplicity and accuracy to determine the best model. We also describe general techniques to optimize a specific generative model. In particular, we address the problem of creating a suitable objective function that is sufficiently continuous for use with finite-difference based optimization techniques. Our technique for model recovery and subsequent manipulation and editing is demonstrated on real objects—a spoon, bowl, ladle, and cup—using a simple tree of possible generative models.

We believe that higher-level model representations are extremely important, and their recovery for actual objects is a fertile area of research towards which this thesis is a step. However, our work is preliminary and there are currently several limitations. The user is required to create a model hierarchy (and supply methods to provide an initial guess for model parameters within this hierarchy); the use of a large pre-defined class of models can help alleviate this problem. Further, we have demonstrated our technique on only a simple tree of generative models. While our approach is fairly general, a real system would require a tree that is significantly larger. Our methods work only where the entire object can be accurately represented as a single generative model; future work could use constructive solid geometry operations on simple generative models to represent more complicated shapes. We believe that many of the above limitations can be addressed in future work, allowing us to easily acquire and process three-dimensional shape in a simple, intuitive and efficient manner.

Item Type:Thesis (Master's thesis)
Subject Keywords:Computer Science and Physics
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Computer Science
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Arvo, James R.
Thesis Committee:
  • Unknown, Unknown
Defense Date:2 March 1998
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Computer Science Technical Reports1998.05
Funding AgencyGrant Number
NSF Science and Technology Center for Computer Graphics and Scientific VisualizationASC-8920219
Army Research Office Young Investigator AwardDAAH04-96-100077
Alfred P. Sloan FoundationUNSPECIFIED
Record Number:CaltechTHESIS:10162018-111851476
Persistent URL:
Related URLs:
URLURL TypeDescription DocumentCaltech Computer Science Technical Report 1998.05
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11234
Deposited By: Kathy Johnson
Deposited On:16 Oct 2018 18:29
Last Modified:02 Dec 2020 02:39

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