Type of Document Dissertation Author Liu, Xiangdong URN etd-158151259631631 Title Analysis and Reduction of Moire Patterns in Scanned Halftone Pictures Degree PhD Department Computer Science Advisory Committee
Advisor Name Title Abbott, A. Lynn Campbell, James B. Jr. Heath, Lenwood S. Shaffer, Clifford A. Ehrich, Roger W. Committee Chair Keywords
- moire patterns
- image processing
- fourier analysis
Date of Defense 1996-05-01 Availability unrestricted AbstractIn this dissertation we provide a
comprehensive theory for the formation of a
moire pattern in a sampled halftone image. We
explore techniques for restoring a sampled
halftone image with a moire pattern and
techniques for preventing a moire pattern when
a halftone picture is scanned. Specifically, we
study the frequency, phase, and spatial
geometry of a moire pattern. We observe and
explain the half period phase reversal
phenomenon that a moire pattern may exhibit.
As a case study, we examine the moire
patterns generated by a commercial scanner.
We propose three restoration methods,
including a notch filtering method, a simulation
method, and a relaxation method. We also
describe a moire prevention method, the
partial inverse Fourier transform method.
Finally, we propose a research agenda for
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