METHOD AND APPARATUS FOR INCREASING THE ACCURACY OF DIMENSIONAL MEASUREMENTS MADE WITH VIDEO CAMERAS

摘要

Video cameras (200), such as charge coupled device cameras (200), are used for optically making dimensional measurements (Figs. 2-3). For example, such cameras are used for laser beam analysis (Figs. 2-3). Such cameras (200) have drawbacks including baseline offset error, shading error, pixel-to-pixel fixed pattern offsets, and poor signal-to-noise ratio (Figs. 2-3). Methods and apparatus to correct for these errors (Figs. 5 and 7-8), without losing any desired signal components, are described. The method and apparatus (Figs. 5 and 7-8) are particularly suited to laser beam performance measurements.