1990 年 30 巻 7 号 p. 496-502
The outline of the software for the grain size measurement developed by the Grain Size Measurement Group in the Committee on Materials Evaluation by Image Analysis Basic Research Association on Specific Subjects sponsored by the Iron and Steel Institute of Japan is described. It consists of three parts being binarization of the input image and grain boundary thinning, repair of the grain boundary, and the measurement and its statistical treatment of grain size. The emphasis is put on the first two processes and the effect of changing the default parameters for binarization and thinning processes on the result of the following repair process is discussed. Then the effect of sample preparation condition on the results of these processes is examined using a common specimen but having different states of polishing and etching. It is shown that for such specimens as polished to 3 μm or finer diamond paste the repair process can be successfully done to give a grain network which well represents the original image. It is found that the variation in etching conditions hereby examined less affects the results. Through these discussions practical usefulness and limitations of the software are visualized.