A New Procedure for Automatic High Precision Measurements of the Position and Width of Bands in Backscatter Kikuchi Patterns

Abstract

A high reliability and precision of crystal orientation data obtained through automatic analysis of backscatter Kikuchi patterns (BKP) from the SEM require a high quality of the band position data which is provided by an image analysis procedure. This paper presents a new pattern recognition procedure which is capable of providing accurate measurements of the location and width of 10 to 15 bands in BKPs of average quality. The procedure is based on the Hough transform (HT) for line detection, and applies a special backmapping technique for generating two simplified HTs which separately focus on bright and dark lines in the patterns. A coordinated search for peaks in the two HTs leads to precise measurements of both the position and width of bands in the patterns. The performance of the new procedure was tested on 100 patterns of varying quality obtained from a sample of partly recrystallised copper. A quantitative comparison of the new procedure with the traditional HT-based procedure shows that the former provides significantly more reliable and precise band position measurements. Furthermore, the computational costs of the new procedure are about 20 percent smaller than for the traditional procedure.