Metrology system utilizing points-from-focus type processes with glare reduction

Abstract

A metrology system is provided including a lighting configuration and camera which are controlled to acquire image stacks of a workpiece, wherein each image stack is acquired utilizing different lighting (e.g., corresponding to different lighting positions). Sets of pixel intensity values from the image stacks are utilized to determine a composite stack which includes one pixel intensity value for each pixel position and focus position. At least some of the pixel intensity values of the composite stack are determined according to a glare reduction process which determines a corresponding pixel intensity value for the composite stack that is less than a maximum pixel intensity value of the corresponding set of pixel intensity values. Focus curve data is determined based at least in part on the pixel intensity values of the composite stack, wherein the focus curve data indicates three dimensional positions of a plurality of surface points on the workpiece.