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United States Patent | 5,689,591 |
Balram and Moura | November 18, 1997 |
The present invention is directed to an apparatus and method for converting a noncausal, two dimensional signal representative of a digitized image into an equivalent data format that can be filtered by recursive filters. The first step is to estimate an optimal set of parameters by: generating data representative of a potential matrix which represents the signal for a given set of parameters; filtering the potential matrix to arrive at a statistically equivalent recursive data format; inputting white noise to the recursive data format to generate k samples of the signal; obtaining an average value for the correlation {.chi..sub..tau. }; generating data representative of a gradient of a likelihood function; using that data to minimize the likelihood function; comparing the arrived at set of parameters to a previously arrived at set of parameters to determine whether the difference therebetween is within a desired tolerance; and repeating the previous steps until an optimal set of parameters is estimated. The next step is to generate data representative of a potential matrix using the optimal set of parameters. That potential matrix is filtered to arrive at a statistically equivalent recursive representation. The equivalent, recursive representation may be used, for example, for image compression or image smoothing.
Inventors: | Balram; Nikhil (Boca Raton, FL); Moura; Jose M. F. (Pittsburgh, PA) |
Assignee: | Carnegie Mellon University (Pittsburgh, PA) |
Appl. No.: | 854200 |
Filed: | March 20, 1992 |
Current U.S. Class: | 382/276; 382/260; 382/265 |
Intern'l Class: | H04N 001/00 |
Field of Search: | 382/56,260,265,276 358/430,432,433,261.2,133,426 |
5001560 | Mar., 1991 | Ericsson | 358/133. |
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