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Current project members

Past members:

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Funding

This work has been funded by NSF grants and by grants from the Colorado Advanced Software Institute:

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Semi-Automated Segmentation

One of the most tedious jobs in medical image processing is hand-drawing the boundaries around tissue of interest. We are exploring ways of training neural networks to duplicate the decisions made by a human anatomist while the human is tracing boundaries, then letting the neural network complete the tracing, with corrections from the human when necessary. Stew Crawford-Hines completed his Ph.D. dissertation in this area in 2003: Earlier publications on this approach include: Also see our examples using medical images.

A prototype, in MATLAB, of a complete system for neural-net-assisted tracing of region contours and the assembly into 3-dimensional models is described in these slides from a talk on our work. Here is an MS PowerPoint version.

A final report from our 1997-98 CASI grant is available in gzipped postscript.

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Converting Polygon Meshes to NURBS

Visible Productions, Inc., of Fort Collins, CO, produces 3-D human models that are recognized as some of the most accurate models in the world. Their models currently are based on meshes of 3-D triangles. Such meshes can be rendered as smooth surfaces by interpolating color values across a triangular mesh, but for a number of applications the smooth surface must be explicitly represented. Clients for Visible Productions' models have asked for surfaces defined by NURBS (Non-Uniform Rational B-Splines). This project will develop and implement algorithms for transforming polygonal meshes into NURBS. This requires a time-intensive, interative optimization process. We are investigating the use of neural networks to by-pass a large part of the optimization process.

Our recent projects have been funded by CASI and by an NSF SBIR grant. Material available from this work includes:

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Terrain Modeling

The Forest Service often needs to visualize a given terrain at various stages of forest growth. This need, plus the fact that terrain elevation data is abundant while texture and color data of terrain is not, has led us to the following study. With the help of Denis Dean in the Department of Forest Sciences at CSU, we have trained neural networks to predict the color of a small area of terrain given only the elevation data:

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Fast Calculation of Radiosity Form Factors

One of the most computationally expensive steps in radiosity is the calculation of the form factors between any two patches in a scene. Building a neural network approximation to the form factor calculation could drastically reduce the complexity of this calculation, making real-time calculation of form factors possible. This has been investigated by Charles Martin in

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Neural Networks in Computer Graphics Research in CS at CSU, Charles W. Anderson / anderson@cs.colostate.edu

Copyright © 1998 Charles Anderson