关键词: 图像处理, 工业CT, Facet模型, 亚像素, 面积测量

Abstract: In order to improve the accuracy of ICT（Industry Computerized Tomography） image measurement，a sub-pixel area measurement method based on Facet model is studied，and applied in actual ICT images.Firstly，an edge detection method based on Facet model is used to extract the sub-pixel edges.Secondly，the method of minimizing distance search is studied to separate and sort the edge of the measured object.At last，Green formula is adopted to compute the area.The edge detection method based on Facet model can achieve higher accuracy，reduce noise，and offer accurate data for further area measurement.The method of minimizing distance search method can separate the edge points of the measured object from the discontinuous edges of whole image，obtain sorted edge point chain，and offer available data for area computing.The measure method in this paper is based on sub-pixel edge；break through the restriction of measure precision by image resolution.Experiments have been done on emulation images and actual CT images，and the results prove that the accuracy of this paper’s method is higher than the method of counting pixel.

Key words: image processing, Industry Computerized Tomography（ICT）, Facet model, sub-pixel, area measurement