AUTOMATIC HIGH-PRECISION MEASUREMENTS OF THE LOCATION AND WIDTH OF KIKUCHI BANDS IN ELECTRON BACKSCATTER DIFFRACTION PATTERNS

The demands for reliability and precision of crystal orientation data obtained through automatic analysis of electron backscattering pattern s (EBSPs) in the SEM result in similar demands on the quality of the b and position data which is provided by an image analysis procedure. Th is paper describes a new image processing procedure which is capable o f providing accurate measurements of the location and width of typical ly 10-15 bands in digitized EBSPs of average quality. The new procedur e is based on the Hough transform (HT) for line detection, and employs a special backmapping technique for generating two simplified HTs whi ch separately focus on bright and dark lines in the images. A coordina ted search for peaks in the two HTs leads to precise estimates of both the position and the width of bands in the patterns. A visual evaluat ion of the data produced by the new procedure shows that it performs s ignificantly better than the conventional procedure with regard to bot h reliability and precision. Additionally, the measured band width dat a are fairly precise and can be used for obtaining a more robust and r eliable indexing of the bands. Finally, the computational costs of the new procedure are smaller than for the conventional procedure.