MEASUREMENT OF OBJECTS

摘要

There is disclosed a method for measuring an object comprising: 1. projecting an interference fringe pattern onto the object using sources of e.m. radiation; 2. measuring the phase shift and image intensity of the fringe pattern across an image field; 3. measuring the intensity of background illumination across the image field; 4. modifying the measurements of the fringe pattern by subtracting an amount corresponding to the measured background illumination across the image field; and 5. generating a 3-D height map of the object using the modified measurements.