Automated optical grading of timber

Peter J. Sobey

doi:10.1117/12.25088

1 February 1991 Automated optical grading of timber

Peter J. Sobey

Proceedings Volume 1379, Optics in Agriculture; (1991) https://doi.org/10.1117/12.25088
Event: Advances in Intelligent Robotics Systems, 1990, Boston, MA, United States

Abstract

Australia grows large quantities of radiata pine for domestic consumption and a significant proportion of this is graded to an Australian Standard Appearance Grade. This paper describes automating the visual inspection of this timber in order to speed processing and improve quality control of the product. The requirement is to detect and identify the visual features on the surface of the timber after the surface has been dressed. These features include sound and encased knots of various sizes pith bark bluestain holes and wane. The image is captured using a linear array CCD camera as the board moves underneath on a conveyor belt. The first stage is to detect the areas that contain features. The image is divided into smaller local areas and first and second order statistical measures are calculated. These form the input to a neural network that has been trained to classify the local areas into clear and feature areas. The choice of measures is crucial to the ability of the neural network to perform the classification of local areas. The second stage is to determine the type of feature in the feature local areas. Various methods are employed to determine a threshold that segments the feature correctly. The size of the feature can be used to identify it uniquely. The list of features and their positions forms the input to the grading program. The grading rules defmed

Citation Download Citation

Peter J. Sobey "Automated optical grading of timber", Proc. SPIE 1379, Optics in Agriculture, (1 February 1991); https://doi.org/10.1117/12.25088

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available