LI Qingli ,WANG Yongqiang ,HAO Tianlu

(Tangshan College, Tangshan 063000)

Abstract: In this paper, an on -line machine vision system for the measurement of geometric dimensions of ceramic tile is introduced, which grabs the images scanned by area-array CCD or CMOS camera. The software system includes both the algorithm for image processing and the measurement algorithm for geometric dimensions. The image processing algorithmb which uses direction masks and subpixel edge detecting is used to locate the edge points exactly. The real -time high precision and non-contact measurement of ceramic tile's geometric dimensions is realized by the Hough transform and least squares pose estimation.

Keywords: imaging measurement, edge detection, subpixel, hough transform, least squares method