Abstract

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.

© 1977 Optical Society of America

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

H. Fujii, J. Uozumi, and T. Asakura
J. Opt. Soc. Am. 66(11) 1222-1236 (1976)

Roughness measurements of metal surfaces using laser speckle

Hitoshi Fujii and Toshimitsu Asakura
J. Opt. Soc. Am. 67(9) 1171-1176 (1977)

Measurement of surface roughness properties by using image speckle contrast

Hitoshi Fujii, Toshimitsu Asakura, and Yoshio Shindo
J. Opt. Soc. Am. 66(11) 1217-1222 (1976)

Statistical properties of laser speckle produced in the diffraction field

Junji Ohtsubo and Toshimitsu Asakura
Appl. Opt. 16(6) 1742-1753 (1977)

Non-Gaussian speckle with correlated weak scatterers: a computer simulation

Hitoshi Fujii
J. Opt. Soc. Am. 69(11) 1573-1579 (1979)