Contour extraction apparatus, contour extraction method, and contour extraction program
First Claim
1. A contour extraction apparatus extracting at least one contour of a target object from images obtained by an image pickup of the target object by cameras, the contour extraction apparatus comprising:
- a node locator locating a plurality of nodes on a periphery of a region, which includes the target object, within the image;
a contour deformation unit deforming the contour, which is formed by connecting nodes at a predetermined connection order, by shifting the position of each node to the position where a predefined energy function becomes minimum;
an internode distance calculator measuring internode distances about all combination of nodes constituting the contour excepting the internode distance between adjacent nodes; and
a connection creator creating a connection line to divide the contour when a combination of nodes whose internode distance is below a first threshold value exists, whereinthe connection line connects one of nodes in the combination with the node adjacent to the other node in the combination,the node adjacent to the other node is the node being positioning upstream or downstream in the predetermined connection order with respect to the other node, andthe first threshold value is determined in accordance with the distance to the target object.
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Accused Products
Abstract
To provide a contour extraction apparatus which can perform much more quickly the contour division when required while reducing the cost for computing. In contour extraction unit 32: a plurality of nodes are located on a periphery of the target object by the node locator 32A; the contour, which is formed by connecting nodes at a predetermined connection order, is deformed by the contour deformation unit 32B; an internode distance about all combination of nodes excepting the inter node distance between adjacent nodes is computed by the internode distance calculator 32C; it is checked by the connection creator 32D whether or not the combination of nodes whose internode distance is below a first threshold value exists, a connection line to divide the contour is created, the connection line connects one of nodes in the combination with the node adjacent to the other node in the combination, and the node adjacent to the other node is the node being positioning upstream or downstream in the predetermined connection order with respect to the other node.
13 Citations
10 Claims
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1. A contour extraction apparatus extracting at least one contour of a target object from images obtained by an image pickup of the target object by cameras, the contour extraction apparatus comprising:
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a node locator locating a plurality of nodes on a periphery of a region, which includes the target object, within the image; a contour deformation unit deforming the contour, which is formed by connecting nodes at a predetermined connection order, by shifting the position of each node to the position where a predefined energy function becomes minimum; an internode distance calculator measuring internode distances about all combination of nodes constituting the contour excepting the internode distance between adjacent nodes; and a connection creator creating a connection line to divide the contour when a combination of nodes whose internode distance is below a first threshold value exists, wherein the connection line connects one of nodes in the combination with the node adjacent to the other node in the combination, the node adjacent to the other node is the node being positioning upstream or downstream in the predetermined connection order with respect to the other node, and the first threshold value is determined in accordance with the distance to the target object.
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2. A contour extraction apparatus for extracting at least one contour of a target object from images obtained by an image pickup of the target object by cameras, the contour extraction apparatus comprising:
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a node locator locating a plurality of nodes on a periphery of a region, which includes the target object, within the image; a contour deformation unit deforming the contour, which is formed by connecting nodes at a predetermined connection order, by shifting the position of each node to the position where a predefined energy function becomes minimum; an internode distance calculator measuring internode distances about all combination of nodes constituting the contour excepting the internode distance between adjacent nodes; and a connection creator creating a connection line to divide the contour when a combination of nodes whose internode distance is below a first threshold value exists, wherein the connection line connects one of nodes in the combination with the node adjacent to the other node in the combination, the node adjacent to the other node is the node being positioning upstream or downstream in the predetermined connection order with respect to the other node, and the first threshold value is determined in accordance with the distance to the target object and is set large as the distance to the target object becomes short. - View Dependent Claims (3, 4, 5, 6, 7, 8)
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9. A method for extracting at least one contour of a target object from images obtained by an image pickup of the target object by cameras, the method comprising the steps of:
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a node locating step locating a plurality of nodes on a periphery of a region, which includes the target object, within the image; a contour deforming step deforming the contour, which is formed by connecting nodes at a predetermined connection order, by shifting the position of each node to the position where a predefined energy function becomes minimum; an internode distance calculating step measuring internode distances about all combination of nodes constituting the contour excepting the internode distance between adjacent nodes; and a connection creating step creating a connection line to divide the contour when a combination of nodes whose internode distance is below a first threshold value exists, wherein the connection line connects one of nodes in the combination with the node adjacent to the other node in the combination, the node adjacent to the other node is the node being positioning upstream or downstream in the predetermined connection order with respect to the other node, and the first threshold value is determined in accordance with the distance to the target object.
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10. A computer program encoded on a computer-readable medium for extracting at least one contour of a target object from images obtained by an image pickup of the target object by cameras, the program controlling the functions comprising:
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a node locator locating a plurality of nodes on a periphery of a region, which includes the target object, within the image; a contour deformation unit deforming the contour, which is formed by connecting nodes at a predetermined connection order, by shifting the position of each node to the position where the predefined energy function becomes minimum; an internode distance calculator measuring internode distances about all combination of nodes constituting the contour excepting the internode distance between adjacent nodes; and a connection creator creating a connection line to divide the contour when a combination of nodes whose internode distance is below a first threshold value exists, wherein the connection line connects one of nodes in the combination with the node adjacent to the other node in the combination, the node adjacent to the other node is the node being positioning upstream or downstream in the predetermined connection order with respect to the other node, and the first threshold value is determined in accordance with the distance to the target object.
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Specification