Profile Measurement by Two-pitch Grating Projection.

Shape measurement by the grating projection technique in a microscope

3D Profile Measurement by Color Pattern Projection and System Calibration

In this paper, we present a new color structured lighting for 3D profile measurement by projecting a pattern of color stripes. The advantage of using color pattern is that it simplifies the difficult matching problem of using a multiple-line stripe pattern. The problem of finding the correct color stripe correspondence between light source and images is solved by accurately calibrating the syst...

Scanning Projection Grating Moire Topography

One problem with moiré topography for 3D surface metrology is the so called 2π-ambiguity limiting the maximum step height difference between two neighboring sample points to be less than half the equivalent wavelength of moiré fringes. To cope with the ambiguity problem, a special scheme of scanning moiré technique is proposed by resorting to the frequency domain fringe analysis that is in fact...

Optical Measurement by Back Projection

One of the tasks specified for the vision group of the RIPR project is the implementation of a run time inspection cell which is able to identify a small object, and to subsequently inspect it using a single camera, referred to as the inspection camera, attached to a robot arm. As a definite example, we may want to determine whether a hole has been machined on a particular face of the object wi...

A New Compensation Method for Measurement of Thread Pitch Diameter by Profile Scanning

For measurement of existing thread parameters using profile scanning, system error increases as pitch diameter, difference between the calibrating thread and measuring thread increases with the single gauge calibration method. There are several alignment deviations affecting the measurement of pitch diameter. To reduce the system error, a compensation method using two standard thread gauges to ...