Apparatus and method

Abstract

Apparatus and method of automatic detection of position and orientation of one or more game pieces within the bounds of a game surface, the or each game piece carrying a unique identification marker, optically monitoring said game surface with an optical sensing device including optically monitoring for the unique identification marker of the or each game piece, said monitoring further including controlling the illumination of said game surface with electromagnetic radiation and receiving image data of the or each unique identification marker from said optical sensing device, and processing said image data to detect position and orientation of said one or more game pieces relative to said optical sensor device.

Description

[0001] APPARATUS AND METHOD

[0002] This invention relates to an automatic tracking system for a game which includes moving objects.

[0003] According to a first aspect of the present invention, there is provided apparatus comprising a game surface over which one or more game pieces are movable, the one or more game pieces carrying a unique identification marker, an optical sensor device directed toward said game surface, a controller device, illuminating means serving to emit electromagnetic radiation towards said game surface, and a data processing device, the arrangement being such that said optical sensor device is arranged to receive image data of the game surface including the unique identification marker of the or each game piece on the game surface, the game surface being illuminated by said illuminating means, wherein the controller device is connected to the optical sensor device and the illuminating means and serves to control the illuminating means in response to the image data received by the optical sensor device, said data processing device serving to detect from said image data of the or each unique identification marker a position and orientation of said one or more game pieces relative to said optical sensor device.

[0004] According to a second aspect of the present invention, there is provided a method of automatic detection of position and orientation of one or more game pieces within the bounds of a game surface, the or each game piece carrying a unique identification marker, optically monitoring said game surface with an optical sensing device including optically monitoring for the unique identification marker of the or each game piece, said monitoring further including controlling the illumination of said game surface with electromagnetic radiation and receiving image data of the or each unique identification marker from said optical sensing device, and processing said image data to detect position and orientation of said one or more game pieces relative to said optical sensor device.

[0005] Owing to these two aspects, the detection of the position and orientation of the or each game pieces and their unique identification markers can be both scalable and robust against partial occlusion, offering reliable detection even in challenging lighting conditions and at varying distances or angles. Furthermore, the unique identification marker provides a highly efficient, low-cost method for 3-dimensional localization and orientation detection in machine vision systems.

[0006] Two-dimensional representation of binary information, is primarily used for pose estimation and location identification in computer vision applications.

[0007] The optical sensor device is preferably a camera device advantageously equipped to detect light in the visible and / or infrared electromagnetic spectrum.

[0008] The game pieces are used for carrying a unique identification marker which the optical sensor device captures in a digital form.

[0009] The environment in which the game surface exists requires illumination via the illumination means which are preferably in the form of a lighting array emitting electromagnetic radiation in the visible and / or infrared spectrum to ensure marker visibility to the optical sensor device.

[0010] Advantageously, a software subsystem is engineered to operate on the data processing device to interpret the digital form of the unique identification marker of the game piece and to accurately detect and decode the game piece marker.

[0011] The controller device is arranged to automatically adjust the illumination of the game surface to effectively handle contrast and brightness variations within the visible and / or infrared spectrum.

[0012] In order that the present invention can be clearly and completely disclosed, reference will now be made, by way of example only to the accompanying drawings, in which:-

[0013] Figure l is a plan view of four game pieces, each carrying a unique identification marker, Figure 2 is a schematic diagram of a first embodiment of a system for the detection of the position and orientation of one or more game pieces on a game board relative to an optical sensing device,

[0014] Figure 3 is a flow diagram of the operation of the apparatus of Figure 1, Figure 4 is a view similar to Figure 1, but of a second embodiment of the system, and Figure 5 is a flow diagram of the operation of the apparatus of Figure 2.

[0015] Referring to Figure 1, a game piece 120 comprises a unique identification marker in the form of a square fiducial emblem 2 comprised of a binary matrix residing within a black boundary. This emblem 2 serves as the unique identification marker in a variety of machine vision contexts, including, but not limited to, camera calibration, game piece orientation and location detection.

[0016] The binary matrix grid of the emblem 2 can have variable sizes such as 4x4, 5x5, 6x6, up to 7x7, where each cell within the grid corresponds to either a binary one or zero, represented by black or white squares respectively. The matrix codifies unique identification information, allowing each individual emblem 2 to be distinctly recognizable by an appropriately trained machine vision system. To ensure rotational invariance, a distinct arrangement of cells, for example three black corners and one white corner, is designed into the unique identification marker, allowing the machine vision system to discern the marker's orientation in 3- dimensional space, even when the game piece is rotated.

[0017] A vast number of unique emblems 2 are possible, each emblem 2 being identifiable through a vision algorithm capable of recognizing and decoding this form of binary pictographic symbology.

[0018] Referring to Figures 2 and 3, a first embodiment of a system 4 for the detection of the position and orientation of the one or more game pieces 120 on a game surface or board 121 is shown and utilizes the two-dimensional fiducial emblems 2 for machine vision applications. The system 4 further comprises a data processing device or server 100, an optical sensor device 105 in the form of a camera device and preferably a tracking camera device, a controller device 110 in the form of a lighting control unit and a plurality of illumination devices 115a and 115b in the form of light-emitting devices which are capable of emitting electromagnetic radiation in the visible and / or infrared spectrum.

[0019] In use, at the start of a game and throughout the game period, the tracking camera 105, which has its field of vision covering substantially the whole of the game surface 121, captures real-world video or image data to be converted into a digital form. This capture also includes video or image data relating to the emblems 2 carried by the game piece(s) 120. There tracking camera 105 does not need to have a single field of vision covering substantially the whole of the game surface as a plurality of tracking cameras may be used with the their respective fields of vision can be electronically stitched together to form a field of vision covering substantially the whole of the game surface 121.

[0020] The captured video or image data is fed to the lighting controller unit 110 connected to the tracking camera 105 by way of the data processing server 100. The lighting control unit 110 dynamically adjusts the lighting conditions of a game environment in real-time, such as by making adjustments to brightness, contrast, and exposure, based on feedback from the tracking camera 105 and the video or image data. In this way, the system 4 continuously monitors performance and adapts the lighting conditions 12 in the game environment in order to maximize visibility and distinctiveness of the or each tracked game piece 120, enhancing the overall tracking accuracy and robustness. This adaptive illumination greatly assists in locations where lighting conditions may impede tracking.

[0021] The data processing device 100 and a computer vision sub-system analyses 14 the video or image data to identify and extract the unique identification marker patterns of the emblems 2. The computer vision sub-system implements a series of image processing steps of the video or image data captured by the tracking camera 105, such as edge detection, feature extraction, and pattern matching. In this way, following data capture, the computer vision sub-system analyses the video or image data, identifying and extracting game piece features from the scene rather than recognising specially designed game pieces specific to the game being played. As a result of the image processing steps carried out by the computer vision subsystem, the unique identification marker patterns of the emblems 2 relative to the tracking camera 105 are detected 16. The computer vision sub-system then calculates the transformation matrix for the emblem 2 that relates the individual emblem's coordinate system relative to the tracking camera's coordinate system, thus determining the position and orientation of the emblem 2 relative to the tracking camera 105. The transformation matrix provides information about the translation (position) and rotation (orientation) of the emblem 2 in three-dimensional space.

[0022] By continuously analysing the video or image data feed and continuously updating the position and orientation of the emblems 2, continuous tracking of the movement of the game pieces 120 is achieved in real-time.

[0023] Advantageously, displaying the real-time tracking information and displaying it on a user interface allows the ability to overlay 18 the real world video or image data with virtual objects in the form of computer-generated graphics, thereby creating a live association between the physical and digital world, and enhancing a user experience.

[0024] Referring to Figures 4 and 5, a second embodiment of the system 4 deploys an infrared (IR) system that relies on the or each emblem 2 being either constructed from IR-reflective material or the or each game piece being retrofitted with IR-emitting devices, such as LEDs. This IR-based system is designed to operate outside of the human visible electromagnetic spectrum, providing an unobtrusive solution for real-world contexts and comprises the data processing server 100, the tracking camera 105, the lighting controller unit 110, the illuminating devices 115a and 115b emitting electromagnetic radiation in the visible spectrum, the game board 121 and the game piece(s) 120 as with the first embodiment, but further includes an IR illuminating device 117 emitting electromagnetic radiation in the IR spectrum towards the game board 121.

[0025] In this embodiment, the tracking camera 105 is also arranged to operate within the IR spectrum to capture reflected IR radiation from the game board 121. Captured IR radiation including that reflected from the IR emblems is then translated into digital information. Alternatively, the tracking camera 105 from Figures 2 and 3 can be used if equipped with an IR-pass filter, allowing only the IR wavelengths through while blocking the radiation in the visible spectrum.

[0026] The IR illuminating device 117 forms the IR light source for the game environment and preferably take the form of and IR LED array to ensure emblem visibility to the IR camera 105. The IR light source 117 casts an IR illumination throughout the game environment to allow for effective detection of the emblems 2.

[0027] The software sub-system of the server 100 is specifically engineered to interpret the unique IR image input to accurately detect and decode the binary matrix inscribed within the emblems 2, similar to the first embodiment of Figures 2 and 3. The lighting controller unit 110, as with the first embodiment, automatically makes adjustments to the IR illumination to effectively handle contrast and brightness variations within the IR spectrum, differing from those in the visible light spectrum.

[0028] The emblems 2 are preferably either made from IR-reflective materials or fitted with IR- emitting LEDs as already mentioned and such emblems are designed to be highly responsive to the IR illumination device 117, thereby providing clear, detectable signals to the IR tracking camera 105.

[0029] Potential IR interference and presence from other IR light sources from other devices operating within the IR spectrum in or around the game environment, such as specific security cameras may cause those other devices to detect the emblems 2. Thus, the system 4 is to be designed and implemented to provide precautions to ensure system integrity and effectiveness in diverse operational environments.

[0030] In use, the system 4 incorporating marker-based tracking methodology within computer vision monitors the location and alignment of the game piece(s) in the game environment. The system 4 of Figures 4 and 5 utilizes IR emblems 2, reflecting and / or emitting electromagnetic radiation outside the visible spectrum, thereby rendering the tracking process invisible to the naked eye. The system also integrates the lighting controller unit 110 that adjusts illumination conditions of the game environment in real-time.

[0031] The specifically designed emblems, made of IR-reflective material or IR-emitting LEDs, are strategically placed on the or each game piece. These emblems consist of unique visual patterns that the computer vision sub-system is able to detect and identify, even within the IR spectrum.

[0032] Initiating the IR tracking operation involves the acquisition 6 of an image or video feed using the data captured from the tracking camera 105, which is capable of detecting the IR emblems. Such data is directed 8 into the lighting controller unit 110 which acts to dynamically fine-tune lighting parameters 10 such as brightness, contrast, and exposure, utilizing feedback from the camera 105. Through continuous evaluation of the tracking performance and real-time adaptation of the lighting conditions 12, the lighting control unit 110 ensures optimal visibility and distinction of the or each tracked game piece in the IR spectrum, boosting overall tracking precision and reliability.

[0033] Subsequently, the computer vision sub-system scrutinizes the image or video data 14 to locate and isolate the emblem patterns within the game environment scene. This process involves various image processing procedures such as edge detection, feature extraction, and pattern matching; all engineered to work with IR imagery.

[0034] Upon detection of the emblem patterns, the computer vision sub-system calculates their position and orientation 16 relative to the tracking camera 105. This is achieved by determining the transformation matrix linking the emblem's coordinate system with that of the tracking camera. The transformation matrix yields information on the translation (position) and rotation (orientation) of the emblem in three-dimensional space.

[0035] By constantly analysing the image or video feed and updating the position and orientation of the marker, the technology is capable of real-time tracking of game piece movement. The resultant data is leveraged to overlay 18 physical objects with computer-generated graphics, establishing a dynamic correlation between the 30 physical and digital realms. By utilizing the lighting controller unit 110 to dynamically adjust illumination conditions in the game environment, the system 4 recognizes and tracks the uniquely marked game piece(s), eliminating the need for specially designed game pieces specific to the game being played.

Claims

CLAIMS1. Apparatus comprising a game surface over which one or more game pieces are movable, the one or more game pieces carrying a unique identification marker, an optical sensor device directed toward said game surface, a controller device, illuminating means serving to emit electromagnetic radiation towards said game surface, and a data processing device, the arrangement being such that said optical sensor device is arranged to receive image data of the game surface including the unique identification marker of the or each game piece on the game surface, the game surface being illuminated by said illuminating means, wherein the controller device is connected to the optical sensor device and the illuminating means and serves to control the illuminating means in response to the image data received by the optical sensor device, said data processing device serving to detect from said image data of the or each unique identification marker a position and orientation of said one or more game pieces relative to said optical sensor device.

2. Apparatus according to claim 1, wherein the or each unique identification marker in the form of a square fiducial emblem.

3. Apparatus according to claim 1 or 2, wherein the optical sensor device has its field of vision covering substantially the whole of the game surface.

4. Apparatus according to any preceding claim, wherein the optical sensor device is a camera device equipped to detect light in the visible and / or infrared electromagnetic spectrum.

5. Apparatus according to any preceding claim, wherein the illumination means are in the form of a lighting array emitting electromagnetic radiation in the visible spectrum to ensure marker visibility to the optical sensor device.

6. Apparatus according to any preceding claim, wherein the illumination means are in the form of a lighting array emitting electromagnetic radiation in the infrared spectrum to ensure marker visibility to the optical sensor device.

7. Apparatus according to any preceding claim, wherein the controller device dynamically adjusts lighting conditions of a game environment including the game surface in real-time, by adjusting conditions including brightness, contrast, and exposure, based on feedback from the optical sensor device.

8. Apparatus according to any preceding claim, and further comprising a software subsystem arranged to operate on the data processing device to interpret a digital form of the unique identification marker of the or each game piece and to accurately detect and decode the or each game piece marker.

9. Apparatus according to claim 8, wherein the software sub-system is a computer vision sub-system arranged to implement a series of image processing steps of data captured by the optical sensor device, including edge detection, feature extraction, and pattern matching.

10. Apparatus according to claim 9 as appended to claim 7, wherein the computer vision sub-system analyses the data, identifying and extracting game piece features from the game environment.

11. Apparatus according to claims 9 or 10, wherein the computer vision sub-system serves to calculate a transformation matrix for the or each unique identification marker that relates a coordinate system for each unique identification marker relative to a coordinate system of the optical sensor device, and thereby determine a position and orientation of the unique identification marker relative to the optical sensor device.

12. Apparatus according to claim 11, wherein the transformation matrix provides information about a position and orientation of the unique identification marker in three-dimensional space.

13. Apparatus according to any preceding claim, and further comprising a user interface serving to display real world captured data with virtual objects.

14. A method of automatic detection of position and orientation of one or more game pieces within the bounds of a game surface, the or each game piece carrying a unique identification marker, optically monitoring said game surface with an optical sensing device including optically monitoring for the unique identification marker of the or each game piece, said monitoring further including controlling the illumination of said game surface with electromagnetic radiation and receiving image data of the or each unique identification marker from said optical sensing device, and processing said image data to detect position and orientation of said one or more game pieces relative to said optical sensor device.

15. A method according to claim 14, wherein the illumination is with light in the visible electromagnetic spectrum.

16. A method according to claim 14 or 15, wherein the illumination is with light in the infrared electromagnetic spectrum.

17. A method according to any one of claims 14 to 16, and further comprising the optical sensor device capturing in digital form the or each unique identification marker of respective game pieces.

18. A method according to claim 17, wherein a software subsystem operates on the data processing device to interpret the digital form of the or each unique identification marker and detecting and decoding the or each unique identification marker.

19. A method according to any one of claims 14 to 18, and further comprising automatically adjusting the illumination of the game surface using the controller device.

20. A method according to claim 19, wherein the adjusting comprises making adjustments to brightness, contrast, and exposure, based on feedback from the optical sensor device.

21. A method according to any one of claims 14 to 20, and continuously monitoring the or each game piece and adapting the illuminating.

22. A method according to any one of claims 18 to 21, wherein the software sub-system is a computer vision sub-system analysing data captured by the optical sensor device to identify and extract the or each unique identification marker.

23. A method according to claim 22, wherein the computer vision sub-system implements a series of image processing steps of the data captured by the optical sensor device, such steps including edge detection, feature extraction, and pattern matching.

24. A method according to claim 22 or 23, wherein following data capture, the computer vision sub-system analyses the captured data, thereby identifying and extracting game piece features from a game environment including the game surface.

25. A method according to claim 23 or 24, wherein the image processing steps carried out by the vision subsystem, identifies the unique identification marker relative to the optical sensor device.

26. A method according to claim 25, and subsequently calculating a transformation matrix for the or each unique identification marker that relates the individual unique identification marker coordinate system relative to the coordinate system of the optical sensor device, thereby determining the position and orientation of the unique identification marker relative to the optical sensor device.

27. A method according to any one of claims 17 to 26, wherein continuously analysing the captured data and continuously updating the position and orientation of the or each unique identification marker results in continuous tracking of the movement of the or each game piece in real-time.

28. A method according to claim 27, and further comprising displaying the real-time movement tracking on a user interface allowing overlaying real world data with virtual objects.

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