Journal ArticleDOI
Image Formation for Coherent Diffuse Objects: Statistical Properties
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TLDR
In this paper, the properties of the amplitude and illuminance of the images of coherently illuminated diffuse objects are studied, where uniform and non-uniform objects are considered and a linear transformation of a nonstationary gaussian stochastic process followed by a square-law detection is considered.Abstract:
The properties of the amplitude and illuminance of the images of coherently illuminated diffuse objects are studied. Uniform and nonuniform objects are considered. The image illuminance is considered to result from a linear transformation of a nonstationary gaussian stochastic process followed by a square-law detection. Expressions are obtained for the mean, autocorrelation, variance, and spatial power spectral density of the amplitude and of the illuminance. Interpretation of the results led to conclusions concerning the speckle size, the noise power in the image, and the transfer function of an optical system when the object diffuses coherent light. When the autocorrelation width of the random fluctuations of the object amplitude is small compared to the impulse response of the system, the mean illuminance in the image plane is that which would be given by an incoherent object having the same luminance as the object considered; the average speckle size is equal to that of the impulse response of the system; the average transfer function of the system is the incoherent transfer function; and the distribution of the noise spatial frequencies does not depend upon the form of the signal, but only upon its total energy. Other results concerning the image statistics have also been obtained.read more
Citations
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Journal ArticleDOI
Statistics of Speckle in Ultrasound B-Scans
TL;DR: In this article, the authors derived autocorrelation functions and power spectra derived from B-scans of a scattering phantom containing many scatterers per resolution cell, leading naturally to the definition of the average speckle spot or cell sue, and this inturn is comparable to the resolution cell.
Book ChapterDOI
Statistical Properties of Laser Speckle Patterns
TL;DR: In this article, the first-order statistics of the complex amplitude, intensity and phase of speckle are derived for a free-space propagation geometry and for an imaging geometry.
Journal ArticleDOI
Adaptive restoration of images with speckle
TL;DR: This work model the speckle according to the exact physical process of coherent image formation and accurately represents the higher order statistical properties of speckel that are important to the restoration procedure.
Journal ArticleDOI
Resolution: a survey
A.J. den Dekker,A. van den Bos +1 more
TL;DR: This paper reviews the concept of optical resolution and concludes that in the end, resolution is limited by systematic and random errors resulting in an inadequacy of the description of the observations by the mathematical model chosen.
Journal ArticleDOI
A review of speckle filtering in the context of estimation theory
TL;DR: It is shown that speckle filtering can be effective only in locally stationary scenes, and structural-multiresolution versions of the Lee (1980) and Frost et al. (1982) filters are developed for optimum application of these filters in the context of nonstationary scene signals.
References
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Journal ArticleDOI
Autocorrelation Function and Power Spectral Density of Laser-Produced Speckle Patterns
TL;DR: In this paper, the autocorrelation function of the speckle pattern so recorded is shown to be proportional to the diffraction pattern corresponding to the illumination function plus a constant.
Journal ArticleDOI
Some effects of target-induced scintillation on optical radar performance
TL;DR: In this paper, the statistical performance of pulsed optical radars that use energy detection is considered, and the physical factors influencing the number of observed correlation cells for the cases of partial and total interception of the transmitted beam are examined.
Journal ArticleDOI
An analysis of the granularity of scattered optical maser light
L. Allen,D.G.C. Jones +1 more
Journal ArticleDOI
Space-Variant Image Formation*
Adolf W. Lohmann,D. P. Paris +1 more
TL;DR: The purpose of this paper is to investigate image-forming systems which are linear but space variant, which may exceed performance limitations which are inherent in linear space-invariant systems.