AUTOMATIC LOCALIZATION OF ELECTRON BACKSCATTERING PATTERN BANDS FROM HOUGH TRANSFORM

An important and challenging aspect of the development of a system for fully automated electron backscattering pattern (EBSP) analysis is th e design of reliable digital image processing routines for automatic d etection and localisation of the bands in the digitised patterns. Proc edures based on the Hough transform which permit precise localisation of a large number of bands in digital EBSPs are described in detail. S pecial attention is pain to the analysis and post-processing of the Ho ugh space which ensure a high insensitivity to noise and a high precis ion of the measured band positions. The possibilities for further impr ovements and extensions of the procedures are also discussed, includin g the possibility of extracting band width information from the Hough transform. To demonstrate these possibilities, a new procedure is outl ined and shown to be capable of providing high precision estimates of the EBSP band positions and, in addition, fairly precise estimates of the band widths. (C) 1996 The Institute of Materials.