A system for dimensional analysis of mechanical objects by means of optical filtering

Non-contact electrooptical techniques offer the possibility of using automatic measurement for on-line dimensional analysis and quality control. In this paper a simple method, based on optical image elaboration using filtering techniques in the Fourier plane, is presented. The method enhances the signal-to-background ratio and can eliminate undesired spatial components in the image light distribution. The result of pre-filtering is a quasi- digital presentation of the object profile that reaches the CCD camera directly.

A preliminary implementation of the system is described, both for one- and two-dimensional ob- jects, and significant experimental results are pre- sented.