COMPUTER-READABLE STORAGE MEDIUM, IMAGE RECOGNITION APPARATUS, IMAGE RECOGNITION SYSTEM, AND IMAGE RECOGNITION METHOD

• US 20120219228A1
• Filed: 08/04/2011
• Published: 08/30/2012
• Est. Priority Date: 02/24/2011
• Status: Active Grant

• Current Assignee: Nintendo Company Limited
• Original Assignee: Nintendo Company Limited
• Inventors: Osako, Satoru, Maruko, Ryota
• Granted Patent: US 8,625,898 B2
• Time in Patent Office: Days
• US Class Current: 382/199
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06V 10/243 by compensating for image skew or non-uniform image deformations
• CPC Class Codes: G06V 10/247 by affine transforms, e.g. correction due to perspective effects; Quadrilaterals, e.g. trapezoids
• CPC Class Codes: G06V 10/44 Local feature extraction by analysis of parts of the pattern, e.g. by detecting edges, contours, loops, corners, strokes or intersections; Connectivity analysis, e.g. of connected components

Abstract

First, a plurality of vertices of a contour of an object or of a design are detected from an image. Then, a predetermined number of division points are generated on each of sides connecting the plurality of detected vertices, so as to divide each side of at least one pair of two opposing sides into unequal parts. Then, a plurality of sample points are determined on the basis of straight lines connecting the division points on the two opposing sides to one another, and on the basis of pixel values of the sample points, it is determined whether or not a predetermined object or design is displayed in an area surrounded by the plurality of vertices in the image.

Claims

1. A computer-readable storage medium having stored thereon an image recognition program causing a computer of an information processing apparatus to function as:

image acquisition means for acquiring an image;

vertex detection means for detecting from the image a plurality of vertices of a contour of an object or of a design;

division point generation means for generating a predetermined number of division points on each of sides connecting the plurality of vertices to each other, so as to divide each side of at least one pair of two opposing sides into unequal parts;

sample point determination means for determining a plurality of sample points on the basis of straight lines connecting the division points on the two opposing sides to one another; and

distinction means for, on the basis of pixel values of the sample points, determining whether or not a predetermined object or design is displayed in an area surrounded by the plurality of vertices in the image.

2. The computer-readable storage medium according to claim 1, wherein

the division point generation means generates the division points on each side of at least one pair of two opposing sides such that the closer to one end of each side of the two opposing sides, the denser the division points.

3. The computer-readable storage medium according to claim 1, wherein

the division point generation means divides each side of at least one pair of two opposing sides into unequal parts in accordance with a ratio of a distance between one end of one side of the two opposing sides and a corresponding one end of the other side;

to a distance between the other ends.

4. The computer-readable storage medium according to claim 1, the image recognition program further causing the computer to function as:

determination means for determining whether or not, among the plurality of sides connecting the plurality of vertices to each other, given two opposing sides are parallel to each other, wherein

the division point generation means includes;

equal division means for, when the determination means has determined that any two opposing sides are parallel to each other, generating the division points so as to divide each side of the two opposing sides into equal parts; and

unequal division means for, when the determination means has determined that any two opposing sides are not parallel to each other, generating the division points so as to divide each side of the two opposing sides into unequal parts.

5. The computer-readable storage medium according to claim 1, wherein

the division point generation means includes:

first vanishing point calculation means for calculating a first vanishing point, the first vanishing point being an intersection of straight lines extending from a first side and a second side, respectively, the first side and the second side opposing each other;

second vanishing point calculation means for calculating a second vanishing point, the second vanishing point being an intersection of straight lines extending from a third side and a fourth side, respectively, the third side and the fourth side opposing each other;

second straight line calculation means for calculating a second straight line, the second straight line being parallel to a first straight line connecting the first vanishing point to the second vanishing point, the second straight line passing through the vertex furthest from the first straight line;

first equal division means for, on a line segment connecting an intersection of the straight line passing through the first side and the second straight line to an intersection of the straight line passing through the second side and the second straight line, generating a plurality of first equal division points so as to divide the line segment into equal parts;

second equal division means for, on a line segment connecting an intersection of the straight line passing through the third side and the second straight line to an intersection of the straight line passing through the fourth side and the second straight line, generating a plurality of second equal division points so as to divide the line segment into equal parts;

first generation means for, on the basis of straight lines connecting the first vanishing point to the first equal division points, generating the division points on each of the third side and the fourth side so as to divide each of the third side and the fourth side into unequal parts; and

second generation means for, on the basis of straight lines connecting the second vanishing point to the second equal division points, generating the division points on each of the first side and the second side so as to divide each of the first side and the second side into unequal parts.

6. The computer-readable storage medium according to claim 1, wherein

the image acquisition means repeatedly acquires images, and

the vertex detection means detects the plurality of vertices from the images repeatedly acquired by the image acquisition means.

7. The computer-readable storage medium according to claim 1, wherein

the distinction means determines, by comparing the pixel values of the sample points with pixel values corresponding to the predetermined object or design that are stored in advance, whether or not the predetermined object or design is displayed in the area surrounded by the plurality of vertices in the image.

8. An image recognition apparatus comprising:

image acquisition means for acquiring an image;

vertex detection means for detecting from the image a plurality of vertices of a contour of an object or of a design;

division point generation means for generating a predetermined number of division points on each of sides connecting the plurality of vertices to each other, so as to divide each side of at least one pair of two opposing sides into unequal parts;

sample point determination means for determining a plurality of sample points on the basis of straight lines connecting the division points on the two opposing sides to one another; and

distinction means for, on the basis of pixel values of the sample points, determining whether or not a predetermined object or design is displayed in an area surrounded by the plurality of vertices in the image.

9. An image recognition method comprising:

an image acquisition step of acquiring an image;

a vertex detection step of detecting from the image a plurality of vertices of a contour of an object or of a design;

a division point generation step of generating a predetermined number of division points on each of sides connecting the plurality of vertices to each other, so as to divide each side of at least one pair of two opposing sides into unequal parts;

a sample point determination step of determining a plurality of sample points on the basis of straight lines connecting the division points on the two opposing sides to one another; and

a distinction step of, on the basis of pixel values of the sample points, determining whether or not a predetermined object or design is displayed in an area surrounded by the plurality of vertices in the image.

10. An image recognition system comprising:

image acquisition means for acquiring an image;

vertex detection means for detecting from the image a plurality of vertices of a contour of an object or of a design;

division point generation means for generating a predetermined number of division points on each of sides connecting the plurality of vertices to each other, so as to divide each side of at least one pair of two opposing sides into unequal parts;

sample point determination means for determining a plurality of sample points on the basis of straight lines connecting the division points on the two opposing sides to one another; and

distinction means for, on the basis of pixel values of the sample points, determining whether or not a predetermined object or design is displayed in an area surrounded by the plurality of vertices in the image.

11. An image recognition system including an image recognition apparatus and a marker in which a design is drawn, the image recognition apparatus comprising:

a capturing section for capturing the marker;

image acquisition means for acquiring an image from the capturing section;

vertex detection means for detecting from the image a plurality of vertices of a contour of the marker or of the design;

division point generation means for generating a predetermined number of division points on each of sides connecting the plurality of vertices to each other, so as to divide each side of at least one pair of two opposing sides into unequal parts;

sample point determination means for determining a plurality of sample points on the basis of straight lines connecting the division points on the two opposing sides to one another; and

distinction means for, on the basis of pixel values of the sample points, determining whether or not a predetermined design is displayed in an area surrounded by the plurality of vertices in the image.