INFORMATION PROCESSING METHOD AND INFORMATION PROCESSING APPARATUS

• US 20090245681A1
• Filed: 03/23/2007
• Published: 10/01/2009
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kobayashi, Kazuhiko
• Granted Patent: US 8,335,400 B2
• Time in Patent Office: Days
• US Class Current: 382/275
• CPC Class Codes: G06T 2207/30244 Camera pose
• CPC Class Codes: G06T 7/74 involving reference images or patches
• CPC Class Codes: G06T 7/80 Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration

Abstract

Markers are laid out to express a predetermined code string by a plurality of continuous markers. The markers which form a marker string include at least two types of markers having different features which can be identified by image processing. Markers detected in the captured image are converted into numerical information, and are collated based on the numerical information and the predetermined code string. Using information associated with the markers, the coordinate information of each collated marker is calculated. The position and orientation of an image capturing device are calculated using the coordinate information. With a simple arrangement, the position and orientation of an image capturing device can be calculated.

Claims

1. An information processing method for calculating a position and orientation of an image capturing device which captures an image of a physical space on which a plurality of markers are one-dimensional set, comprising:

a marker detection step of detecting the plurality of markers from a captured image;

a conversion step of converting the plurality of markers detected in the marker detection step into corresponding numerical information;

a collating step of collating a part, which matches the numerical information, of a predetermined code string;

a coordinate calculation step of calculating coordinate values of the plurality of detected markers on the physical space using the collating result and information associated with a layout of the markers; and

a position and orientation calculation step of calculating the position and orientation of the image capturing device using a detection result in the marker detection step and the coordinate values.

2. The method according to claim 1, further comprising a correction step of correcting a distortion of an image region which includes the plurality of markers detected in the marker detection step, and

in that the conversion step includes a step of performing the conversion using an image after the correction is made.

3. The method according to claim 1, characterized in that the conversion step includes a step of performing the conversion by identifying a type of each of the plurality of markers.

4. The method according to claim 3, characterized in that the conversion step includes a step of classifying the plurality of markers into types, and converting each type of marker into numerical information.

5. The method according to claim 1, wherein the information associated with the layout of the markers includes at least one of information associated with a layout direction of markers, information associated with an interval between neighboring markers, and coordinates of a reference marker.

6. The method according to claim 1, wherein the predetermined code string is a code string in which only one autocorrelation function yields “

1”

within a cycle.

7. A computer-readable recording medium storing a program for making a computer apparatus execute steps in an information processing method according to claim 1.

8. An information processing apparatus for calculating a position and orientation of an image capturing device which captures an image of a physical space on which a plurality of markers are one-dimensional set, characterized by comprising:

marker detection unit which detects the plurality of markers from the captured image;

conversion unit which converts the plurality of markers detected by said marker detection unit into corresponding numerical information;

collating unit which collates a part, which matches the numerical information, of a predetermined code string;

coordinate calculation unit which calculates coordinate values of the plurality of detected markers on the physical space using the collating result and information associated with a layout of the markers; and

position and orientation calculation unit which calculates the position and orientation of the image capturing device using a detection result of said marker detection unit and the coordinate values.