Method, apparatus and program product for searching knots in wood
First Claim
1. A method executed by a programmed processor for searching knots in wood, the method comprising:
- 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 said knot candidate from said at least one figure;
varying threshold levels of gray value for said clipped partial image such that an image is obtained at each of said threshold levels, said image including said knot candidate;
performing a second calculation, said second calculation comprising calculating a degree of circularity and stability of said knot candidate at each of said threshold levels;
identifying one of said images from said plurality of images comprising a selected threshold level, said selected threshold level corresponding to a level at which said circularity and said size stability of said knot candidate is a maximum value with respect to said circularity and said size stability values of said knot candidate in said other images;
determining a configuration of said knot candidate at said selected threshold level;
detecting said knot candidate as a knot when said degree of said circularity of said knot candidate is greater than a predetermined circularity degree at said selected threshold level.
1 Assignment
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Accused Products
Abstract
The photographing means of the present apparatus photographs a piece of wood, while the image processing means calculates degrees of circularity from the photographed images of the piece of wood, and detects images with significant degrees of circularity as knots. In addition, the image processing means 1 clips a portion including a knot from the photographed image of the piece of wood, deems a portion clipped at a predetermined threshold among the color spaces of each pixel of the clipped portions to be a blackened portion, and determines black portions with a high proportion of a number of pixels of the blackened portion to the number of pixels of the clipped portion of the knot as dead knots.
17 Citations
16 Claims
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1. A method executed by a programmed processor for searching knots in wood, the method comprising:
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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 said knot candidate from said at least one figure; varying threshold levels of gray value for said clipped partial image such that an image is obtained at each of said threshold levels, said image including said knot candidate; performing a second calculation, said second calculation comprising calculating a degree of circularity and stability of said knot candidate at each of said threshold levels; identifying one of said images from said plurality of images comprising a selected threshold level, said selected threshold level corresponding to a level at which said circularity and said size stability of said knot candidate is a maximum value with respect to said circularity and said size stability values of said knot candidate in said other images; determining a configuration of said knot candidate at said selected threshold level; detecting said knot candidate as a knot when said degree of said circularity of said knot candidate is greater than a predetermined circularity degree at said selected threshold level. - View Dependent Claims (2, 3, 4, 13, 14)
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5. An apparatus for searching knots in wood, comprising:
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a photographing unit for photographing pieces of wood; an image processing unit, said image processing unit being programmed for; 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 said knot candidate from said at least one figure; varying threshold levels of gray value for said clipped partial image such that an image is obtained at each of said threshold levels, said image including said knot candidate; performing a second calculation, said second calculation comprising calculating a degree of circularity and stability of said knot candidate at each of said threshold levels; selecting one of said images from said plurality of images, said one of said images comprising a selected threshold level, said selected threshold level corresponding to a level at which said circularity and said size stability of said knot candidate is a maximum value with respect to said circularity and said size stability values of said knot candidate in said other images; determining a configuration of said knot candidate at said selected threshold level; detecting said knot candidate as a knot when said degree of said circularity of said knot candidate is greater than a predetermined circularity degree at said selected threshold level. - View Dependent Claims (6, 7, 8, 15)
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9. A non-transitory computer-readable storage medium storing a program for enabling a computer to function as an image processing apparatus comprising:
a unit programmed for; performing a first calculation, said 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 said knot candidate from said at least one figure; varying threshold levels of gray value for said clipped partial image such that an image is obtained at each of said threshold levels, said image including said knot candidate; performing a second calculation, said second calculation comprising calculating a degree of circularity and stability of said knot candidate at each of said threshold levels; identifying one of said images from said plurality of images, said one of said images comprising a selected threshold level, said selected threshold level corresponding to a level at which said circularity and said size stability of said knot candidate is a maximum value with respect to said circularity and said size stability values of said knot candidate in said other images; determining a configuration of said knot candidate at said selected threshold level; detecting said knot candidate as a knot when said degree of said circularity of said knot candidate is greater than a predetermined circularity degree at said selected threshold level. - View Dependent Claims (10, 11, 12, 16)
Specification