METHOD AND SYSTEM FOR CALCULATING SURFACE HEIGHT MAP OF OBJECT FROM IMAGE STACK BY OBJECT SURFACE OPTICAL SCANNING BY OPTICAL SYSTEM TYPE 2.5 DIMENSIONAL CONTOUR CURVE METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method and system for calculating the surface height map of object from an image stack.SOLUTION: In a method and system for calculating the surface height map of object from an image stack by an object surface optical scanning by optical system type 2.5-dimensional contour curve method, a focal surface is scanned at different heights on the object surface. An image is captured at each height position on the focal surface is an image stack is formed. The scanning of the focal surface includes detecting the displacement of the focal surface in long distance and short distance in order to detect a low spatial frequency component and a high spatial frequency component. The height position of a focal surface is estimated by combining the low spatial frequency component and the high spatial frequency component. The height position of each image in the image stack is calculated on the basis of the estimated height position of each focal surface. The images of the image stack are interpolated to equal interval height positions in order to obtain a corrected image stack. An surface height map of object is calculated from the corrected image stack.SELECTED DRAWING: Figure 1