Wood knot detecting method, device, and program

摘要

A method executed by a programmed processor for searching knots in wood is disclosed. The method comprises photographing a piece of wood by a photographing unit; performing a first calculation comprising calculating degrees of circularity of each figure in the photographed images of the piece of wood and setting at least one figure comprising a circularity corresponding to a knot candidate; clipping a partial image including the knot candidate from the at least one figure and varying threshold levels of gray value for the clipped partial image such that an image is obtained at each of the threshold levels. The image includes the knot candidate. The method further includes performing a second calculation comprising calculating a degree of circularity and stability of the knot candidate at each of the threshold levels and identifying one of the images from the plurality of images comprising a selected threshold level. The selected threshold level corresponds to a level at which the circularity and the size stability of the knot candidate is a maximum value with respect to the circularity and the size stability values of the knot candidate in the other images. The method further includes determining a configuration of the knot candidate at the selected threshold level and detecting the knot candidate as a knot when the degree of the circularity of the knot candidate is greater than a predetermined circularity degree at the selected threshold level. An apparatus for searching for knots in wood comprising a photographing unit for photographing pieces of wood and an image processing unit programmed to carry out the above described method is also disclosed.