Estimation of orientation characteristic of fibrous material

A new statistical method for estimating the orientation distribution of fib res in a fibre process is suggested where the process is observed in the fo rm of a degraded digital greyscale image. The method is based on line trans ect sampling of the image in a few fixed directions. A well-known method ba sed on stereology is available if the intersections between the transects a nd fibres can be counted. We extend this to the case where, instead of the intersection points, only scaled variograms of grey levels along the transe cts are observed. The nonlinear estimation equations for a parametric orien tation distribution as well as a numerical algorithm are given. The method is illustrated by a real-world example and simulated examples where the ell iptic orientation distribution is applied. In its simplicity, the new appro ach is intended for industrial on-line estimation of fibre orientation in d isordered fibrous materials.