Graphics identification program

• US 20050270289A1
• Filed: 08/10/2004
• Published: 12/08/2005
• Est. Priority Date: 06/03/2004
• Status: Active Grant

• Current Assignee: Nintendo Company Limited
• Original Assignee: Nintendo Company Limited
• Inventors: Momose, Hiroshi
• Granted Patent: US 7,535,460 B2
• Time in Patent Office: Days
• US Class Current: 345/443
• CPC Class Codes: A63F 2300/1075 using a touch screen
• CPC Class Codes: A63F 2300/301 using an additional display connected to the game console, e.g. on the controller
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text
• CPC Class Codes: G06T 11/203 Drawing of straight lines or curves
• CPC Class Codes: G06V 30/1423 the instrument generating sequences of position coordinates corresponding to handwriting preprocessing or recognising digital ink G06V30/32

Abstract

An information processing device executing a graphics identification program detects a trace drawn on an input surface as coordinate points in chronological order. Coordinate points for representing the trace are selected from a group of coordinate points arranged in chronological order. Lengths of line segments obtained by connecting the selected coordinate points in chronological order are calculated. Also, for each line segment, an absolute angle and a relative angle are calculated. A trace graph in an orthogonal coordinate system, whose first axis indicates a line segment distance and whose second axis indicates an angle of a line segment whose start point is one of the selected coordinate points, is compared with a reference graphic graph representing a reference graphic in the orthogonal coordinate system, thereby identifying a reference graphic represented by a reference graphic graph which most closely resembles the trace graph as a shape of the trace.

Claims

1. A computer readable storage medium for storing a graphics identification program to be executed by a computer for identifying a graphical shape of a trace drawn by a user on an input surface of an input device, wherein

the graphics identification program causes the computer to execute:

a detection step of detecting the trace drawn on the input surface as coordinate points in chronological order;

a coordinate point selection step of selecting coordinate points for representing the trace from among a group of the coordinate points in which the detected coordinate points are arranged in chronological order;

a length calculation step of calculating lengths of line segments obtained by connecting the selected coordinate points in chronological order;

an angle calculation step of calculating, for each line segment, an absolute angle which the line segment forms with a previously determined reference straight line or a relative angle which the line segment forms with a line segment adjacent thereto; and

a graphics identification step of comparing a trace graph in an orthogonal coordinate system, whose first axis indicates a distance from a starting point or an ending point of the selected coordinate points to each coordinate point along the line segment and whose second axis indicates an angle of the line segment whose start point is one of the selected coordinate points, with reference graphic graphs respectively representing a plurality of types of previously prepared reference graphics in the orthogonal coordinate system, and identifying a reference graphic represented by a reference graphic graph which most closely resembles the trace graph as a shape of the trace.

2. The storage medium according to claim 1, wherein the trace graph and the reference graphic graph are represented as a step graph in which a portion corresponding to the line segment is composed of a straight line component parallel to the first axis.

3. The storage medium according to claim 1, wherein

the graphics identification step includes:

an area calculation step of calculating an area of a region surrounded by line segments which are not shared by the trace graph and the reference graphic graph in the orthogonal coordinate system for each reference graphic; and

an identification step of identifying a reference graphic having a smallest area among the areas calculated at the area calculation step as a shape of the trace.

4. The storage medium according to claim 3, wherein the trace graph and the reference graphic graph are represented as a step graph in which a portion corresponding to the line segment is composed of a straight line component parallel to the first axis.

5. The storage medium according to claim 1, wherein the graphics identification program further causes the computer to execute a normalization step of normalizing, before comparison between the trace graph and the reference graphic graph is performed at the graphics identification step, a cumulative length of the trace graph while keeping a percentage of a length of each line segment of the trace graph so that a cumulative length of the line segments of the trace graph is equal to a cumulative length of the reference graphic graph.

6. The storage medium according to claim 1, wherein the coordinate point selection step selects coordinate points by thinning out a coordinate point lying within a predetermined distance from a straight line connecting two predetermined coordinate points from the group of the detected coordinate points.

7. The storage medium according to claim 1, wherein the coordinate point selection step selects all of the detected coordinate points.

8. The storage medium according to claim 1, wherein the detection step detects the trace which is drawn without lifting a stylus from the input surface as coordinate points in chronological order.

9. The storage medium according to claim 1, wherein

a display device is connected to the computer, and

the graphics identification program further causes the computer to execute:

a game image display step of displaying a scene of at least a portion of a game space on the display device as a game image; and

a game process step of causing the game image to change by executing a game process associated with the reference graphic identified as a shape of the trace at the graphics identification step depending on a type of the reference graphic.

10. A game apparatus for identifying a graphical shape of a trace drawn by a user on an input surface of an input device, changing game progress based on the identification results, and displaying the change on a display device, comprising:

reference graphic storing means for storing a distance from a starting point or an ending point of vertices of each of a plurality of reference graphics, which is composed of a plurality of vertices and line segments connecting between the vertices, to each vertex along each line segment, and an absolute angle which the line segment forms with a previously determined reference straight line or a relative angle which the line segment forms with a line segment adjacent thereto;

detection means for detecting the trace drawn on the input surface as coordinate points in chronological order;

coordinate point selection means for selecting coordinate points for representing the trace from a group of the coordinate points in which the detected coordinate points are arranged in chronological order;

length calculation means for calculating lengths of line segments obtained by connecting the selected coordinate points in chronological order;

angle calculation means for calculating, for each line segment, an absolute angle which the line segment forms with a previously determined reference straight line or a relative angle which the line segment forms with a line segment adjacent thereto; and

graphics identification means for comparing a trace graph in an orthogonal coordinate system, whose first axis indicates a distance from a starting point or an ending point of the selected coordinate points to each coordinate point along the line segment and whose second axis indicates an angle of the line segment whose start point is one of the selected coordinate points, with a reference graphic graph representing each of a plurality of types of reference graphics stored in the reference graphic storing means in the orthogonal coordinate system, and identifying a reference graphic represented by a reference graphic graph which most closely resembles the trace graph as a shape of the trace.

11. The game apparatus according to claim 10, wherein the trace graph and the reference graphic graph are represented as a step graph in which a portion corresponding to the line segment is composed of a straight line component parallel to the first axis.

12. The game apparatus according to claim 10, wherein

the graphics identification means includes:

area calculation means for calculating an area of a region surrounded by line segments which are not shared by the trace graph and the reference graphic graph in the orthogonal coordinate system for each reference graphic; and

identification means for identifying a reference graphic having a smallest area among the areas calculated by the area calculation means as a shape of the trace.

13. The game apparatus according to claim 12, wherein the trace graph and the reference graphic graph are represented as a step graph in which a portion corresponding to the line segment is composed of a straight line component parallel to the first axis.

14. The game apparatus according to claim 10, further comprising normalization means for normalizing a cumulative length of the trace graph while keeping a percentage of a length of each line segment of the trace graph so that a cumulative length of the line segments of the trace graph is equal to a cumulative length of the reference graphic graph before comparison between the trace graph and the reference graphic graph is performed by the graphics identification means.

15. The game apparatus according to claim 10, wherein the coordinate point selection means selects coordinate points by thinning out a coordinate point lying within a predetermined distance from a straight line connecting two predetermined coordinate points from the group of the detected coordinate points.

16. The game apparatus according to claim 10, wherein the coordinate point selection means selects all of the detected coordinate points.

17. A graphics identification method executed by a computer for identifying a graphical shape of a trace drawn by a user on an input surface of an input device, comprising:

a detection step of detecting the trace drawn on the input surface as coordinate points in chronological order;

a coordinate point selection step of selecting coordinate points for representing the trace from among a group of the coordinate points in which the detected coordinate points are arranged in chronological order;

a length calculation step of calculating lengths of line segments obtained by connecting the selected coordinate points in chronological order;

an angle calculation step of calculating, for each line segment, an absolute angle which the line segment forms with a previously determined reference straight line or a relative angle which the line segment forms with a line segment adjacent thereto; and

a graphics identification step of comparing a trace graph in an orthogonal coordinate system, whose first axis indicates a distance from a starting point or an ending point of the selected coordinate points to each coordinate point along the line segment and whose second axis indicates an angle of the line segment whose start point is one of the selected coordinate points, with a reference graphic graph representing each of a plurality of types of previously prepared reference graphics in the orthogonal coordinate system, and identifying a reference graphic represented by a reference graphic graph which most closely resembles the trace graph as a shape of the trace.