IMAGE-ANALYSIS TECHNIQUES .1. THE MEASUREMENT OF PORE-SIZE DISTRIBUTION

The paper describes digital-processing techniques for determining the pore-size distribution in a fabric. A magnified image of a sample of fabric is captured by a video camera, and the image is processed to determine pore-size distributions according to three definitions. The sizes of the pores in a fabric to be used for filtration, for example, can be classified according to their area, their hydrodynamic diameter, which is determined from the area of the pore and its circumference, and the 'thickness', the diameter of the maximum inscribed circle. The last definition should lead to pore-size distributions which correlate most closely to the laboratory measurement of the pore size of a fabric by sieving glass balls of specified sizes.