Accuracy enhancement of vision metrology through automatic target plane determination

Abstract

In digital close-range photogrammetry, commonly referred to as vision metrology, circular targets are often used for high precision applications. The most common target type used consists of retro-reflective material, which provides a high contrast image with flash photography. The measurement of image coordinates of signalised targets continues to be a factor limiting the achievable accuracy of high-precision vision metrology systems. Mathematical algorithms are used to determine the centres of imaged targets in 2D space. These 2D centroids are then used in a triangulation process to calculate the target position in 3D space. This computational process assumes that the targets represent per..