A machine vision system forautomatically grading hardwood lumber

Abstract

Any automatic system for grading hardwood lumber can conceptually be dividedinto two components. One of these is a machine vision system for locating and identifying grading defects. The other is an automatic grading program that accepts as input the output of the machine vision system and, based on these data, determines the grade of a board. The progress that has been made on developing the first component, the machine vision component, will be reported in this paper. The machine vision system being developed is made up of a subsystem for imaging rough lumber surfaces, a computer vision subsystem for analyzing the image data and identifying grading defects, a materials handling subsystem for moving boards through the imaging devices, a computer for executing the algorithms comprising the computer vision sub-system and, finally, another small computer for controlling all the other components. This paper will describe the progress that has been made on developing all of these components. It will also indicate the directions for future research. A major goal of this research activity is to create a vision technology that will be applicable to not only the grading of hardwood lumber but a number of other forest products related applications as well.