Volume estimation of symmetrical object using laser light sectioning

Abstract

This paper presents a method to estimate volume from three-dimensional characteristics of symmetrical objects by computer vision system using laser light sectioning. The camera captures the image of laser line projected on the object moving on a conveyor. The captured images can be estimated the widths and heights at various locations along the object. The area of cross section can be integrated to be volume of the object. The image data is extracted from the structured laser light projecting on the surface. After image pre-processing, the laser profile is calculated the center of gravity in order to extract the image coordinate. The homography transformation is used to transform the extracted coordinate to the real world distance (in metric system). A metric vision based on light sectioning for estimating the volume of symmetrical shapes (rectangular shape and circular shape) of the object were tested. The accuracy of estimation can apply in the automatic size grading on the conveyer as well.