METHOD AND DEVICE FOR ALIGNMENT OF THREE DIMENSIONAL SHAPE DATA

PURPOSE:To align each site within measured three dimensional shape data, within reference data, by calculating the total of the differences between each value of objective data aherein the low-frequency component is removed and each value of reference data, and by moving a positions on a two dimensional plane of the objective data so that the total becomes the minimum. CONSTITUTION:After the completion of an alignment by manual operation, the measurement of a three dimensional shape by a linear laser beam is effected, and a height image is obtained and inputted from an image arithmetic unit 28 to a data processor 30. Next, about the height image, the operation of a two dimensional digital low-pass filter is effected, a low-frequency component is computed, a reference plane is corrected by subtracting the compulation. If necessary, deforming correction is effected to the height image after the reference plane correction. Then, about the height image after the deforming correction, the reference image is superposed on the measured image, the total of the absolute values of the differences between height values which each picture element has is computed on superposed parts, and a moving quantity of the measured image at which this value becomes the minimum is set down as the optimum moving quantity.