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Quality assurance in wood manufacturing by computer vision
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INTELLIWOOD was a research project promoted by the
European Union. It is
located in the area of wood manufacturing.
Partners in this consortium are small and medium enterprises, institutes of
universities and large wood manufacturing companies from Europe, Australia
and the U.S.
This mixture has several advantages for all partners.
Knowledge will be transferred from universities, which are often
accused to be "ivory towers" of science, to small and medium
enterprises. These enterprises, in the case of INTELLIWOOD
software engineering companies, put the knowledge into
solution packages for the major wood manufacturers.
The aim of the project was to improve quality assurance in wood
manufacturing and to supply an automatic wood classifier.
Such classifiers exist nowadays, but the existing systems have
several disadvantages: first, they use a small variety of
sensors only (mostly grayvalue cameras) and not a
bundle of sensors (keyword sensor-fusion),
second, the methods used
are standard algorithms, which are not adapted for
the problems of wood manufacturing and which are often
scientifically obsolete.
The research interest of
FORWISS is located in the
area of image vision and signal processing.
FORWISS has been already
active in this area for several years. The task of our research group
in the project INTELLIWOOD. is to improve existing methods
and to supply new approaches in this field of interest.
Further information
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Classifying woods for parquets one has to exclude wood not achieving
parquet quality.
In the example above the yellow marked pixels were classified as a resin
pockets and
the red ones as a branch. In order to detect these areas feature vectors of
dimension 484 for all pixels were used. Such a mass of information
contradicts any realtime capability. FORWISS developed a genetic algorithm which reduces this flood of data
to a capable one, without loosing the classifying ability.
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In many wood applications branches beginnings are not wanted.
Therefore it is desirable to locate
such inner branches in logs by methods of computer tomography. This allows
to eliminate inappropriate wood before starting the step in production.
In the example image one can see x-ray images of several logs.
The nails mark the visible beginnings of branches. By x-ray-images
from several views it is possible to reconstruct the 3D progression
of the branches within the inner of the wood.
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X-ray cameras should also be used to detect sapwood on normal wood.
Sapwood is the weaker layer under the bark of a tree. This wood
has a lower quality and should be sorted out.
In the example image one can see a "good" part of wood (above) and
and a part of wood with a higher percentage of sapwood. The graph below
shows to absorption of woods along the red marked line, at
an x-ray energy of 70-80 keV (green), 90-140 keV (red) respectively.
From the projects
ANGIO
and Optical Recycling
FORWISS got expert knowledge in the area of x-ray image processing.
Leader of the projects consortium is the
sensoTech GmbH
company in Graz, Austria, which focuses on realtime image
vision. Further partners in industrial image processing are
the Swedish enterprises svedvision and
Soliton Elektronik. These companies have a strong
interest in improving their methods and techniques through knowledge
from the academic area in which Lignum Research
an university institute in Graz (Austria) is located.
A pure research center is the
Austrian Research Center Seibersdorf
(ARCS),
the largest non-university research institute in Austria.
The ARCS has experiences in high speed image processing.
Final users of the methods and solution packages to develop are
the companies Holzelemente GmbH in Austria and
the Tarkett Sommer AB in Sweden.
Project staff
Project partners
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