Computer simulation study of image speckle patterns with relation to object surface profile

As a further extension of the previous paper and by considering actual objects, the intensity distribution and average contrast of image speckle patterns for two different kinds of objects having an asymmetrical random surface and a Gaussian random surface combined with a periodic sinusoidal variation are investigated on a computer as a function of the surface roughness properties of objects and the point spread of an optical imaging system. The computer simulation study for objects with the asymmetrical random surface indicates that a variation of the average speckle contrast as a function of the above parameters takes almost the same behavior as for objects with a purely Gaussian random surface. The study for objects with the combined surface of Gaussian random and sinusoidal variations shows that the average speckle contrast strongly depends on the combination ratio of these two variations characterized by their standard deviation and correlation length. It becomes again clear that the maximum value of the image speckle contrast is dependent upon the rms surface roughness of objects but not upon their surface profile.

[1]  Toshimitsu Asakura,et al.  A contrast variation of image speckle intensity under illumination of partially coherent light , 1974 .

[2]  J. Goodman.  Statistical Properties of Laser Speckle Patterns , 1963 .

[3]  Toshimitsu Asakura,et al.  Statistical properties of speckle intensity variations in the diffraction field under illumination of coherent light , 1975 .

[4]  First order statistics of speckle produced by weak scattering media , 1975 .

[5]  Toshimitsu Asakura,et al.  Effect of surface roughness on the statistical distribution of image speckle intensity , 1974 .

[6]  Atul K. Jain,et al.  Experiments on the space and wavelength dependence of speckle , 1975 .

[7]  Hans M. Pedersen.  Object-roughness dependence of partially developed speckle patterns in coherent light , 1976 .

[8]  J. Ohtsubo,et al.  Surface Roughness Measurement by Using Speckle Pattern , 1975 .

[9]  Atul K. Jain,et al.  Space and wavelength dependence of speckle intensity , 1974 .

[10]  Toshimitsu Asakura,et al.  Measurement of surface roughness properties by means of laser speckle techniques , 1976 .

[11]  Hans M. Pedersen,et al.  The roughness dependence of partially developed, monochromatic speckle patterns , 1974 .

[12]  Toshimitsu Asakura,et al.  Measurement of surface roughness properties by using image speckle contrast , 1976 .

[13]  Toshimitsu Asakura,et al.  Statistical properties of image speckle patterns in partially coherent light , 1975 .

[14]  H. M. Pedersen.  Theory of speckle dependence on surface roughness , 1976 .