Thomas Asaki's April 2011 Talk
Time and Date: 4:10 pm Tuesday, April 12
Location: 5W Neill Hall, WSU Mathematics Department
Title: Modulation Transfer Function Deconvolution for Imaging Systems
Abstract: Calculating a radiographic device's modulation transfer function (MTF) yields information on the device's ability to image at varying frequencies of light. The current methods to calculate an MTF, while effective, can be computationally inefficient. We thus introduce a new technique for measuring the MTF. This is accomplished by recovering the image's point spread function (PSF) through deconvolution with an ideal representation. With this technique, calculation of the MTF becomes much faster and requires only the imaging of simple objects, e.g. ball bearings, to achieve an accurate result. This method yields not only the one-dimensional MTF of an object but also the two-dimensional MTF, which can reveal possible asymmetries in a device's resolution capabilities.
Speaker Bio: Tom Asaki is from California by way of Montana, Washington and then New Mexico. He has been known to play classic video-games and likes fiddling with anything intricate and challenging, having formed a reputation as a gifted experimenter in PM's lab while obtaining his PhD. His mathematical interests range from variational analysis and optimization to clever algorithms for hard computational problems. While his PhD is in Theoretical and Experimental Physics (under Phil Marston), his last 6-7 years At Los Alamos amounted to a reinvention of himself into an applied mathematician. At this same time he co-founded the DDMA team with Vixie and solved a series of programmatic problems, in the process creating a new toolbox for complicated image analysis problems (in collaboration with Matt Sottile, another former DDMA lead member). At WSU, he is deepening his variational analysis work and throughly enjoys the teaching and mentoring, which was, after all, a major reason for th decision to move to academia. (bio by KRV)
Background Information for Talk: This work started as an undergraduate thesis project for Jonathan Thompson (physics/math). We are in the process of clarifying his results and judging the soundness of the work. We will appreciate your ideas. For background information, you may wish to read about (1) how Modulation Transfer Functions (MTFs) are used in assessing resolving capabilities of imaging systems and (2) stable methods of deconvolution such as positive iterative methods as well as the more traditional Richardson-Lucy and Van Cittert ideas.