A Machine Vision based Lumber Tracing System

In this paper, we introduce a machine vision system for wooden board tracing in sawmills. The goal is to match images taken from boards in the beginning and at the end of the manufacturing process in order to track the movement of individual boards. The task is challenging due to the changing appearance of boards during the process. These are changes in color, texture and physical form. Lighting conditions and camera parameters are also unknown and can change between different camera systems inside a sawmill. Before matching, image alignment is carried out using 2-D to 1-D projection signals. Signals are generated using the statistical properties of gray scale images. Aligned images are then matched using fast and compact local descriptors. The performance of the system was evaluated using over 1000 real life images captured with visual quality control cameras integrated into the production line. A tracing accuracy over 95% was achieved with a high confidence of the individual match.