Through the method of image segmentation, based on the fact that there is a big difference in grey scale between auricle
parenchyma and bone tissue, this article discussed using grey scale threshholding method, that is, using dual grey scale
thresholds to distinguish auricle and surrounding tissues, to process the CT image of auricle. This article provided a
fundament for reversely design individualized 3-d auricle bracket model from the patient's normal side auricle CT image,
and manufacture lifelike auricle bracket through rapid prototyping.