Abstract: A stereo image mosaic method based on global control points is proposed. The global coordinate system can be set up by stable laser spots scattering symmetrically around object to be measured. During every local measurement, the transform relation between probe coordinate system and mosaic camera coordinate system can be obtained by introducing mosaic target into measurement. And the relation between probe coordinate system and global coordinate system can be drawn using mosaic camera as intermediary. Then the results of local measurements can be unified in global system to fulfill the mosaic. This method can avoid multi-signs and preserve object’s original contour. It overcomes the error accumulation of methods based on superposition between neighboring images.

Key words: Global control point, Image mosaic, Shape measurement