A method for processing of trees using machine vision with software means, a system and a wood processing line

A method for processing of trees using machine vision with a software, the method having steps of:

• debarking trees with a debarker having a debarking drum,
• while objects existing in the debarking drum smaller than a selected dimension are removed from among trees through bark openings included in the debarking drum,
• routing trees from the debarking drum over a trap for removing objects that are bigger than a selected dimension from among trees to the trap,
• illuminating trees on a conveyor after the debarking with a lighting device,
• by reflecting indirect lighting via ambient light covers on a section of the conveyor covered with the ambient light covers,
• recording trees on the conveyor after the debarking drum using at least one camera as a detector for creating images,
• detecting automatically a stone or plastic as a harmful object on the conveyor among trees from the images utilising machine vision in the following steps of:
• recognising hue information or gradients as elements from the
• registering the elements to a field of view as registered elements,
• determining element distances in the field of view thus creating three-dimensional information pertaining to the field of view,
• recognising patterns with the help of the registered elements and three-dimensional information, and
• recognising harmful objects with a criterion preselected with the help of the patterns;
• moving the trees forward using the conveyor (20), the method
• stopping the conveyor automatically when the harmful object is detected on the conveyor, and
• removing the harmful object on the conveyor from among trees.