Properties of speckle integrated with a finite aperture and logarithmically transformed 论文
1976Journal of the Optical Society of America引用 220
Surface Roughness and Optical MeasurementsOptical Polarization and EllipsometryOptical measurement and interference techniques
摘要
When image plane speckle intensity integrated over a finite aperture is submitted to a logarithmic transformation, the noise becomes additive and signal independent. The first- and second-order moments of the probability distribution are derived. It is found that the logarithm of speckle noise approaches a normal distribution much faster than speckle intensity. The properties of speckle noise are different from those of film-grain noise; for example, neither Nutting’s law nor Selwyn’s law is satisfied by speckle.