APPLICATION OF STEREO IMAGING FOR RECOGNITION OF CRYSTAL-SURFACE SHAPES

The shape of an interface while a crystal is growing inside a crystal growth furnace is an important measurement to assess the crystal quali ty on-line. If the crystal surface can be visualized by video or X-ray imaging, the interface shape can be determined by the stereo image pr ocessing techniques. This paper presents a methodology to determine th e shape of the solid-melt interface by stereo based imaging techniques whiles the crystal is growing inside a transparent furnace. The metho dology generates a qualitative shape information provided that a good pair of stereo images of the interface can be captured. For a quantita tive shape description, i.e., for the determination of interface point s with respect to a fixed coordinate frame, both cameras must be calib rated. This paper illustrates the methodology for qualitative shape de termination of lead bromide crystal interface.