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Contrast of Photographically Recorded Speckle Patterns
Optica Acta: International Journal of Optics, 1976The probability density function of the irradiance distribution of the incoherent superposition of uncorrelated speckle patterns is calculated. Using this probability density function the contrast of a photographic recording of the irradiance distribution is determined, taking the non-linearity of the film characteristic into account.
Eliasson, B., Dändliker, R.
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Aspects of speckle contrast metrology
SPIE Proceedings, 2010Recent revitalization of interests in applying speckle techniques gives rise to the concern of measurement accuracy. In particular, speckle contrast, an important metric in numerous optical techniques, is affected by many factors related to light sources, propagation media, and receivers.
L. Tchvialeva +6 more
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Speckle evaluation in laser display: From speckle contrast to speckle influence degree
Optics Communications, 2020Abstract Speckle contrast (SC) is universally used to evaluate speckle in laser display, which has virtues of briefness in calculating and definitude in physical meaning. But the results characterized by SC is usually inconsistent with human visual perception.
Dong Zhou Wang +6 more
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Influence of geometry on polychromatic speckle contrast
Journal of the Optical Society of America A, 2007Understanding speckle behavior is very important in speckle metrology application. The contrast of a polychromatic speckle depends not only on surface roughness and the coherence length of a light source, as shown in previous works, but also on optical geometry.
Haishan Zeng +3 more
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Speckle contrast of the sum of N partially correlated speckle patterns
Journal of the Optical Society of America A, 2012In this paper a general method is presented for calculating the theoretical speckle contrast of a sum of correlated speckle patterns, motivated by the need to suppress the presence of speckle in laser projection displays. The method is applied to a specific example, where correlated speckle patterns are created by sequentially passing light through ...
Sigbjørn Vindenes Egge +2 more
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Contrast in speckled imagery with stochastic distances
2010 IEEE International Conference on Image Processing, 201072
Alejandro C. Frery +2 more
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Hadamard speckle contrast reduction
Optics Letters, 2004The condition for a diffuser to produce the maximum speckle contrast reduction with the minimum number of distinct phase patterns is derived. A binary realization of this optimum diffuser is obtained by mapping the rows or columns of a Hadamard matrix to the phase patterns.
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61.3: Simulation and Measurement of Laser Speckle and Speckle Contrast
SID Symposium Digest of Technical Papers, 2012AbstractThe simulation and experimental results of laser speckle and speckle contrast are presented. The correct speckle contrast was obtained when the ratio of the speckle size to the CCD pixel size is larger than 3.5, and the ratio of the maximum speckle intensity to the CCD saturation is in 0.3∼1.0.
Wei-Feng Hsu +2 more
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Geometry influence on polychromatic speckle contrast
SPIE Proceedings, 2006Speckle contrast is widely used in various applications. In this work we develop a simple model to examine the influence of optical geometry on contrast reduction for polychromatic speckle the Fresnel diffraction zone. The model is based on the known fact that the sum of N independent speckle patterns decreases the contrast of the resultant pattern ...
Tim K. Lee +5 more
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Speckle-contrast monitoring of tissue thermal modification
Applied Optics, 2002Measurements of the contrast value of time-averaged speckle-modulated images of cartilage tissue are used to study tissue thermal modification in the case of laser-light treatment. This modification is related to thermally induced internal stress relaxation in the matrix of the treated tissue.
Alexander P. Sviridov +5 more
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