Subpixel Target Location Techniques for 3—D Coordinate Measuring System

The close photogrammetric 3-D coordinate meaurement is a new measuring technology in the fields of the coordinate measurement machine (CMM) in recent yearsl.In this method,we usually place some targets on the measured object and take image of targets to determine the object coordinate.The subpixel location of target image plays an important role in high accuracy 3-D coordinate measuring procedure,In this paper,some subpixel location methods are reviewed and some factors which affect location precision are analyzed. Then we propose bilinear interpolation centroid algorithm.The experiments have shown this algorithm can improve accuracy of target centroid by increasing available pixels.

Subpixel Target Location Techniques for 3-D Coordinate Measuring System

The close photogrammetric 3-D coordinate measurement is a new measuring technology in the fields of the coordinate measurement machine (CMM) in recent years. In this method, we usually place some targets on the measured object and take image of targets to determine the object coordinate. The subpixel location of target image plays an important role in high accuracy 3-D coordinate measuring procedure. In this paper, some subpixel location methods are reviewed and some factors which affect location precision are analyzed. Then we propose bilinear interpolation centroid algorithm. The experiments have shown this algorithm can improve accuracy of target centroid by increasing available pixels.