DETERMINING LOCATION AND ORIENTATION OF A LABELLED CYLINDER USING POINT-PAIR ESTIMATION ALGORITHM

Abstract

In this paper, a new feasible approach is proposed to determine the 3-D location and orientation as well as the radius of a cylinder pasted with a known-height label. The proposed approach uses a rectangle-shaped standard mark composed of two point-pairs for performing monocular image analysis. A monocular image of a labelled cylinder is first taken. Image processing and numerical analysis techniques are then used to set two point-pairs located on the boundary of the visible part of the cylindrical label. According to 3-D imaging geometry, the location and orientation as well as the radius of the cylinder relative to the camera are uniquely determined by using 3-D vector analysis and simple algebraic computation. Owing to the full linearity of the,derivation, this approach can achieve high speed requirement. In addition, no prerequisite restriction is imposed on the image-grabbing process and there is no need to perform the calibration of the focal length since it can be derived. Experimental results, with mean errors less than 3%, prove the feasibility of the proposed approach.