Song Jin

Abstract

The bispectrum of a signal has useful properties such as being zero for a Gaussian random process, retaining both phase and magnitude information of the Fourier transform of a signal, and being insensitive to linear motion. It has found applications in a wide variety of fields. The use of these properties for reducing speckle in coherent imaging systems was investigated. It was found that the bispectrum could be used to restore speckle-degraded images. Coherent speckle noise is modeled as a multiplicative noise process. By using a logarithmic transformation, this speckle noise is converted to a signal independent, additive process which is close to Gaussian when an integrating aperture is used. Bispectral reconstruction of speckle-degraded images is performed on such logarithmically transformed images when we have independent multiple snapshots.

Library of Congress Subject Headings

Image processing; Speckle

Publication Date

3-1-1992

Document Type

Thesis

Department, Program, or Center

Electrical Engineering (KGCOE)

Advisor

Raghuveer, M.

Advisor/Committee Member

Dianat, S.

Advisor/Committee Member

Newman, D.

Comments

Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: TA1632.J56 1992

Campus

RIT – Main Campus

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