Challenge Team Interim Report
Team Number: 047
School Name: Los Alamos High School
Area of Science: Physics - Signal and Image Processing
Project Title: 3D Image Reconstruction from X-Ray Scans
Our project is to write a program which reconstructs a three dimensional (3D) image of an object from x-ray or similar data. This program will be parallelized to run on a multi processor machine. The output willl be displayed using IDL, an interactive graphics language. We are receiving the data for this project from ESA-MT at LANL, the nondestructive testing team. They have a single processor version of the program. Ther are providing us with x-ray data sets. It is also possible that we will receive data from a neutron scanner. We are also using a IDL license donated by Research Sustems Inc.
There are three distinct steps to this project. Each one is a complete project in and of itself. If we finish one we will go on to the next. If the steps prove extremely difficult we will be able to stop after step one. The first project reconstructs a 3D image from a parrallel beam. The next second step is to reconstruct a 3D image from a fan beam. The final step is to reconstruct a 3D image from a cone beam.
Each of these projects is comprised of several different parts suitable for different individuals on the team. One part is a program which calculates one slice of an image. Next a multi processor program which assembles the slices into a 3D image. Lastly the data is transferred to an IDL for 3D viewing.
We expect to finish with one or more programs to take a variable number of x-ray projections and reconstruct a 3D image of the original object. This program will also take a simulated object create the projections, and recreate the image. This demonstrates the error inherent in the process. The programs, with the exception of IDL, will run on multiple processors. We will also benchmark this program on a specific object and compare it to the existing single processor program at LANL. We expect to find that our multi processor program runs faster.
We are currently writing the three different parts of the parallel beam program. The coding of the parallel program will start when we get a account on a machine with a large number of processors. We are currently writing the program for simulating and reconstructing a slice. We are starting to write the IDL program for visualization.
We will begin the fan beam project only after the parallel beam project is completed.
Why a Super Computer:
Aside from the multi processor aspect of this project we need a super computer to handle the massive calculations and the large volume of data. One regular size set of data is over a gigabyte. A standard object requires four thousand calculations involving up to three hundred and sixty pieces. Each calculation requires each piece to be integrated in and filtered. There is no practical way to run this program on a small machine. One data set takes about thirty minutes on a single processor. For a interactive process this is a unacceptably long time.