Measurement of spatial correlation functions using image processing techniques

Journal Article · Mon Apr 01 00:00:00 EST 1985 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.334346· OSTI ID:6004943

Berryman, J G

A procedure for using digital image processing techniques to measure the spatial correlation functions of composite heterogeneous materials is presented. Methods for eliminating undesirable biases and warping in digitized photographs are discussed. Fourier transform methods and array processor techniques for calculating the spatial correlation functions are treated. By introducing a minimal set of lattice-commensurate triangles, a method of sorting and storing the values of three-point correlation functions in a compact one-dimensional array is developed. Examples are presented at each stage of the analysis using synthetic photographs of cross sections of a model random material (the penetrable sphere model) for which the analytical form of the spatial correlations functions is known. Although results depend somewhat on magnification and on relative volume fraction, it is found that photographs digitized with 512 x 512 pixels generally have sufficiently good statistics for most practical purposes. To illustrate the use of the correlation functions, bounds on conductivity for the penetrable sphere model are calculated with a general numerical scheme developed for treating the singular three-dimensional integrals which must be evaluated.

• Research Organization: Lawrence Livermore National Laboratory, P. O. Box 808, L-200, Livermore, California 94550
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6004943
• Journal Information: J. Appl. Phys.; (United States), Vol. 57:7
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CORRELATION FUNCTIONS
MEASURING METHODS
FOURIER TRANSFORM SPECTROMETERS
IMAGE PROCESSING
ELECTRIC CONDUCTIVITY
FOURIER TRANSFORMATION
IMAGES
ISOTROPY
PHYSICAL PROPERTIES
THERMAL CONDUCTIVITY
TRANSPORT THEORY
ELECTRICAL PROPERTIES
FUNCTIONS
INTEGRAL TRANSFORMATIONS
MEASURING INSTRUMENTS
PROCESSING
SPECTROMETERS
THERMODYNAMIC PROPERTIES
TRANSFORMATIONS
440300* - Miscellaneous Instruments- (-1989)
657005 - Theoretical Physics- Optics