U.S. patent application number 12/259181 was filed with the patent office on 2012-11-15 for controller having visually trackable object for interfacing with a gaming system.
This patent application is currently assigned to Sony Computer Entertainment Inc.. Invention is credited to Richard Marks, Anton Mikhailov.
Application Number | 20120289334 12/259181 |
Document ID | / |
Family ID | 41139137 |
Filed Date | 2012-11-15 |
United States Patent
Application |
20120289334 |
Kind Code |
A9 |
Mikhailov; Anton ; et
al. |
November 15, 2012 |
CONTROLLER HAVING VISUALLY TRACKABLE OBJECT FOR INTERFACING WITH A
GAMING SYSTEM
Abstract
Methods, systems and computer programs for determining the
location in a field of play of a game controller are provided. A
ball section is attached to the game controller to locate the
controller using visual information. The method obtains an image of
the field of play where the game controller is present, and then
finds pixels in the image associated with the ball section. The
method further establishes an area encompassing the found pixels
and determines a geometric shape based on the area associated with
the ball. The location of the controller is calculated based on the
geometric shape, with the center of the geometric shape indicating
the horizontal and vertical location of the controller, and the
size of the geometric shape determining the depth of the controller
within the field of play. The location is stored in memory, which
is used to drive an action by the computer.
Inventors: |
Mikhailov; Anton; (Campbell,
CA) ; Marks; Richard; (Pleasanton, CA) |
Assignee: |
Sony Computer Entertainment
Inc.
Tokyo
JP
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20100105475 A1 |
April 29, 2010 |
|
|
Family ID: |
41139137 |
Appl. No.: |
12/259181 |
Filed: |
October 27, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11588779 |
Oct 26, 2006 |
8062126 |
|
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12259181 |
|
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60730659 |
Oct 26, 2005 |
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Current U.S.
Class: |
463/33 ; 463/37;
463/57 |
Current CPC
Class: |
A63F 2300/1093 20130101;
G06F 3/017 20130101; G06F 3/0304 20130101; A63F 13/42 20140902;
A63F 2300/6045 20130101; G06F 3/0346 20130101; A63F 2300/1043
20130101; A63F 13/10 20130101; A63F 13/24 20140902; A63F 13/213
20140902; A63F 13/06 20130101 |
Class at
Publication: |
463/33 ; 463/57;
463/37 |
International
Class: |
A63F 13/04 20060101
A63F013/04; A63F 13/06 20060101 A63F013/06 |
Claims
1. A computer implementing a method to determine a location in a
field of play of a game controller, the method comprising:
obtaining an image of the field of play where the game controller
is present; finding pixels in the image associated with a ball
section connected to the game controller; establishing an area
encompassing the pixels that were found; determining a geometric
shape based on the area associated with the ball; calculating the
location of the controller based on the geometric shape, the center
of the geometric shape indicating the horizontal and vertical
location of the controller, a size of the geometric shape
determining a depth of the controller within the field of play;
storing the location in memory associated with the computer; and
driving an action by the computer based on the stored location.
2. The method as recited in claim 1, wherein determining a
geometric shape further includes, calculating a largest possible
straight line fitting in the area, wherein the geometric shape is a
circle with the largest possible straight line as the circle's
diameter.
3. The method as recited in claim 2, wherein determining a
geometric shape further includes, finding a circle that best
contains the area, wherein the geometric shape is the circle that
best contains the area.
4. The method as recited in claim 1, wherein determining a
geometric shape further includes, making the geometric shape equal
to the area, and calculating a centroid of the geometric shape as
an arithmetic mean of coordinates of pixels in the area, wherein
the centroid is the center of the geometric shape.
5. The method as recited in claim 1, wherein obtaining an image of
the field of play further includes, blurring the image by an image
capture device, wherein more pixels are found in the image
associated with the ball section when blurring the image.
6. The method as recited in claim 1, further including, obtaining
additional images of the field of play, calculating an additional
location of the controller for each additional image, and tracking
movement of the controller based on the additional locations.
7. The method as recited in claim 6, wherein calculating an
additional location further includes, comparing the each additional
image with previously obtained images, averaging the information
from the each additional image and the previously taken images to
calculate the additional location corresponding to the each
additional image.
8. The method as recited in claim 7, wherein weights associated
with ages of the previously obtained images and the each additional
image are used for averaging the information.
9. The method as recited in claim 1, further including, obtaining a
second image with a higher resolution of a reduced area around the
location calculated, calculating a refined location of the
controller based on the second image.
10. The method as recited in claim 1, further including, increasing
a camera resolution before obtaining the image.
11. The method as recited in claim 1, wherein finding pixels
further includes, analyzing subpixels associated with each pixel to
determine if the each pixel is associated with the ball
section.
12. The method as recited in claim 1, wherein the ball section is
illuminated under a first lighting condition and not illuminated
under a second lighting condition.
13. A computer implementing a method to determine a location in a
field of play of a game controller, the method comprising:
obtaining an image of the field of play where the game controller
is present; finding pixels in the image associated with a ring in a
ball section connected to the game controller; establishing an area
encompassing the pixels that were found; determining an ellipse
based on the area associated with the ring; calculating the
location of the controller based on the ellipse, the center of the
ellipse indicating the horizontal and vertical location of the
controller, a size of the ellipse determining a depth of the
controller within the field of play; storing the location in memory
associated with the computer; and driving an action by the computer
based on the stored location.
14. The method of claim 13, wherein determining an ellipse further
includes, determining whether a part of the ring is occluded in the
image, estimating a second area corresponding to a full ring when
the ring is occluded, and determining the ellipse based on the
second area when the ring is occluded.
15. The method as recited in claim 13, wherein the ring is fixed
within the ball section, wherein the length of axes in the ellipse
are used to determine the depth of the controller within the field
of play.
16. The method as recited in claim 15, wherein an orientation of
the axes is used to determine an orientation of the game
controller.
17. The method of claim 13, wherein the ring is illuminated,
wherein finding pixels further includes determining whether pixels
correspond to the illuminated ring.
18. The method of claim 17, wherein the ball section moves in
response to game controller moves in order to place the ring facing
an image capturing device.
19. The method of claim 18, wherein the moves of the ball section
are used to determine an orientation of the controller.
20. A computer implementing a method to determine a location in a
field of play of a game controller, the method comprising:
obtaining an image of the field of play where the game controller
is present; receiving status information from the game controller;
determining a geometric shape associated with a ball section
connected to the game controller; calculating the location of the
controller based on a combination of the status information and
properties of the geometric shape; storing the location in memory
associated with the computer; and driving an action by the computer
based on the stored location.
21. The method of claim 20, wherein the game controller can be held
in different ways, wherein the status information includes buttons
being pressed in the controller to determine the controller
orientation.
22. The method of claim 20, wherein the ball section is enclosed in
a translucid shell enabling an image capturing device to capture
the image of the ball section.
23. The method of claim 22, wherein the translucid shell only
allows the light to pass in the direction from the spherical
section to the image capturing device and not pass in the opposite
direction.
24. The method of claim 20, wherein the ball section vibrates to
increase a number of pixels associated with the ball section,
wherein the status information indicates that the ball is
vibrating.
25. The method of claim 20, wherein the ball section expands to
increase a number of pixels associated with the ball section,
wherein the status information includes a size of the ball
section.
26. The method of claim 20, wherein the status information includes
information from at least one of an accelerometer, a gyroscope or a
magnetometer.
27. The method of claim 26, further including, analyzing sensor
information and the calculated location of the controller over
several frames to determine an orientation of the controller.
28. The method of claim 26, wherein calculating the location
further includes, detecting when the ball section is visible, using
image information for determining the location when the ball
section is visible, and switching to dead reckoning for determining
the location when the ball section is not visible.
29. The method of claim 20, wherein the controller includes a wheel
located around a portion of a body circumference of the controller
and oriented horizontally relative to a holding portion of the
body, the wheel providing controlled directional movement.
30. The method of claim 20, wherein the controller further includes
a wheel input in the controller, wherein driving an action further
includes, detecting an x, y, or z orientation of the game
controller, and moving an item associated with the controller in a
direction of the orientation of the game controller when the wheel
is activated.
31. The method of claim 30, wherein the game controller when
oriented in the y direction causes traversal of a vertical menu,
wherein the game controller when oriented in the x direction causes
traversal of a horizontal menu.
32. A system for determining the location in a field of play of a
game controller, the system comprising: a game controller present
in the field of play; a ball section connected to the controller;
an image capturing device to obtain an image of the field of play;
a computer device connected to the image capturing device, the
computer device including a processor and a memory, the memory
including, an image captured by the image capturing device, a
location corresponding to the image captured, and an image analysis
program to calculate the location, wherein program instructions
from the image analysis program include, program instructions for
finding pixels in the image associated with the ball section;
program instructions for establishing an area encompassing the
pixels that were found; program instructions for determining a
geometric shape based on the area associated with the ball; program
instructions for calculating the location of the controller based
on the geometric shape; and program instructions for driving an
action by the computer device based on the location.
33. A computer program embedded in a computer-readable storage
medium, when executed by one or more processors, for determining
the location in a field of play of a game controller, the computer
program comprising: program instructions for obtaining an image of
the field of play where the game controller is present; program
instructions for finding pixels in the image associated with a ring
in a ball section connected to the game controller; program
instructions for establishing an area encompassing the pixels that
were found; program instructions for determining an ellipse based
on the area associated with the ring; program instructions for
calculating the location of the controller based on the ellipse,
the center of the ellipse indicating the horizontal and vertical
location of the controller, a size of the ellipse determining a
depth of the controller within the field of play; program
instructions for storing the location in memory associated with the
computer; and program instructions for driving an action by the
computer based on the stored location.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to U.S. patent application Ser.
No. 12/145,455, filed Jun. 24, 2008, and entitled "DETERMINATION OF
CONTROLLER THREE-DIMENSIONAL LOCATION USING IMAGE ANALYSIS AND
ULTRASONIC COMMUNICATION", which is incorporated herein by
reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates generally to tracking the
location of a game controller in a field of play, and more
specifically to tracking the location and the movement of a game
controller, which includes a ball attachment, using visual
information.
[0004] 2. Description of the Related Art
[0005] The video game industry has seen many changes over the
years. As computing power has expanded, developers of video games
have likewise created game software that takes advantage of these
increases in computing power. To this end, video game developers
have been coding games that incorporate sophisticated operations
and mathematics to produce a very realistic game experience.
[0006] Example gaming platforms, may be the Sony Playstation.RTM.,
Sony Playstation2.RTM. (PS2), and Sony Playstation3.RTM. (PS3),
each of which is sold in the form of a game console. As is well
known, the game console is designed to connect to a monitor
(usually a television) and enable user interaction through handheld
controllers. The game console is designed with specialized
processing hardware, including a CPU, a graphics synthesizer for
processing intensive graphics operations, a vector unit for
performing geometry transformations, and other glue hardware,
firmware, and software. The game console is further designed with
an optical disc tray for receiving game compact discs for local
play through the game console. Online gaming is also possible,
where a user can interactively play against or with other users
over the Internet.
[0007] As game complexity continues to intrigue players, game and
hardware manufacturers have continued to innovate to enable
additional interactivity and computer programs. A growing trend in
the computer gaming industry is to develop games that increase the
interaction between user and the gaming system. One way of
accomplishing a richer interactive experience is to use wireless
game controllers whose movement is tracked by the gaming system in
order to track the player's movements and use these movements as
inputs for the game. Generally speaking, gesture input refers to
having an electronic device such as a computing system, video game
console, smart appliance, etc., react to some gesture captured by a
video camera that tracks an object.
[0008] However, current object tracking suffers in capture
accuracy. This problem arises because conventional image analysis
can only produce somewhat reliable measurements of the location of
the user in two dimensions, as slight variations in the perceived
shape of the controller makes determining the horizontal and
vertical position of the controller unreliable and very susceptible
to noise. In addition, determining the distance between the camera
and the object being tracked is difficult, as the slight changes in
shape due to movement towards or away from the camera do not
provide enough information to reliably calculate distances between
the camera and the controller.
[0009] It is within this context that embodiments of the invention
arise.
SUMMARY
[0010] Embodiments of the present invention provide methods,
systems and computer programs for determining the location in a
field of play of a game controller. A ball section attached to the
game controller aids in locating the controller using visual
information.
[0011] It should be appreciated that the present invention can be
implemented in numerous ways, such as a process, an apparatus, a
system, a device or a method on a computer readable medium. Several
inventive embodiments of the present invention are described
below.
[0012] In one embodiment, a computer implements a method to
determine a location in a field of play of the game controller. The
method obtains an image of the field of play where the game
controller is present, and then finds pixels in the image
associated with the ball section. The method further establishes an
area encompassing the found pixels and determines a geometric shape
based on the area associated with the ball. The location of the
controller is calculated based on the geometric shape, with the
center of the geometric shape indicating the horizontal and
vertical location of the controller, and the size of the geometric
shape determining the depth of the controller within the field of
play. The location is stored in memory, which is used to drive an
action by the computer.
[0013] In another embodiment, a method is presented to determine
the location in a field of play of a game controller. The method
obtains an image of the field of play and finds pixels in the image
associated with a ring in the ball section connected to the game
controller. Further, the method establishes an area that
encompasses the pixels found associated with the ring. An ellipse
is determined based on the area previously established, and the
location of the controller is calculated based on the ellipse,
where the center of the ellipse indicates the horizontal and
vertical coordinates of the controller, and the size of the ellipse
determines the depth of the controller within the field of play.
The location is stored in memory, which is used to drive an action
by the computer.
[0014] In another embodiment, a method is presented to determine a
location in a field of play of a game controller using a
combination of information sources with respect to the location and
movement of the controller. The method obtains an image of the
controller and receives status information from the game
controller. The status information can be originated in an
accelerometer, a gyroscope or a magnetometer. The method determines
a geometric shape associated with the ball section connected to the
game controller, and calculates the location of the controller by
combining the status information with information about the
geometric shape.
[0015] Other aspects of the invention will become apparent from the
following detailed description, taken in conjunction with the
accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention may best be understood by reference to the
following description taken in conjunction with the accompanying
drawings in which:
[0017] FIGS. 1A-B show embodiments of a game controller with a ball
section attached.
[0018] FIGS. 1C-E depict different operational modes for the game
controller of FIGS. 1A-B.
[0019] FIGS. 2A-2B shows other embodiments of a game controller
with a ball attached.
[0020] FIGS. 3A-3B depict different embodiments of a ball-attached
game controller.
[0021] FIGS. 4A-D show an embodiment of a ball-attached game
controller with interchangeable face-plates.
[0022] FIG. 5 shows a schematic diagram of a multiplayer
environment and the use of visual information to determine the
locations of the different controllers held by the players,
according to one embodiment.
[0023] FIGS. 6A-6D illustrate different embodiments for assigning a
geometric shape to a perceived shape from a captured image.
[0024] FIG. 7 illustrates how to use subpixel analysis to find
pixels corresponding to the ball section in accordance with one
embodiment.
[0025] FIG. 8 shows the effects of blurring an image to improve
shape detection according to one embodiment of the invention.
[0026] FIG. 9 depicts the use of several consecutive captured
images to determine ball location according to one embodiment.
[0027] FIG. 10 illustrates one embodiment for taking an image from
a reduced area of the playing field to increase accuracy.
[0028] FIG. 11 depicts image recognition of a ball with a small
number of pixels, according to one embodiment.
[0029] FIG. 12 depicts one embodiment for image recognition using a
high resolution camera.
[0030] FIGS. 13A-C illustrate ball detection using an illuminated
ring movable to face the camera in accordance with one
embodiment.
[0031] FIGS. 14A-H illustrate detection of a distinguishable ring
in the ball section, according to one embodiment.
[0032] FIGS. 15A-B depict a method to estimate a complete ring area
from a partial arc section.
[0033] FIG. 16 shows and embodiment where the ball vibrates to
increase the perceived ball surface.
[0034] FIGS. 17A-B depict embodiments of a ball that can change
size or appearance to improve detection.
[0035] FIG. 18 shows an embodiment of a game controller with a ball
section enclosed in a shell.
[0036] FIGS. 19A-B describe a controller with sensors for improving
movement tracking, according to one embodiment.
[0037] FIG. 20 depicts using different sources of information to
assess controller position in accordance with one embodiment.
[0038] FIGS. 21A-C describe the use of a wheel in a controller to
initiate computer actions, according to one embodiment.
[0039] FIG. 22 illustrates hardware and user interfaces that may be
used to determine controller location, in accordance with one
embodiment of the present invention.
[0040] FIG. 23 illustrates additional hardware that may be used to
process instructions, in accordance with one embodiment of the
present invention.
[0041] FIG. 24 shows a flow chart describing an embodiment for a
method to determine a location in a field of play of a
ball-attached game controller.
[0042] FIG. 25 includes a flow chart for a method to determine a
location in a field of play of a ball with a distinguishable ring,
according to one embodiment.
DETAILED DESCRIPTION
[0043] The following embodiments describe methods, systems and
computer programs for determining the location in a field of play
of a game controller. A ball section is attached to the game
controller to locate the controller using visual information. The
method obtains an image of the field of play where the game
controller is present, and then finds pixels in the image
associated with the ball section. The method further establishes an
area encompassing the found pixels and determines a geometric shape
based on the area associated with the ball. The location of the
controller is calculated based on the geometric shape, with the
center of the geometric shape indicating the horizontal and
vertical location of the controller, and the size of the geometric
shape determining the depth of the controller within the field of
play. The location is stored in memory, which is used to drive an
action by the computer.
[0044] It will be obvious, however, to one skilled in the art, that
the present invention may be practiced without some or all of these
specific details. In other instances, well known process operations
have not been described in detail in order not to unnecessarily
obscure the present invention.
[0045] FIGS. 1A-B show embodiments of a game controller with a ball
section attached. The ball attached to the controllers can be of
different colors, and in one embodiment, the ball can light up. The
color in the ball can be driven by RGB (Red Green Blue)
Light-Emitting Diodes (LEDs) inside the ball. Additionally, the
brightness of the illuminated ball can be controlled in order to
track the ball under different camera exposure settings. In one
embodiment, the color of the ball is used to differentiate
controllers from different users and among controllers held by the
same user on different hands.
[0046] Although a spherical ball is shown in the controllers of
FIGS. 1A and 1B, the ball can have other shapes for visual tracking
purposes, such as a partial sphere, an imperfect sphere, an
elongated ball (like one used in American football or in rugby), a
cube-like shape, etc.
[0047] The controllers of FIGS. 1A and 1B are designed for one-hand
use, but ball-attached two-hand controllers can also be tracked
using embodiments described herein. In one embodiment, the two
controllers held by the user on different hands are identical, and
in another embodiment the controllers are different. Typically, the
controllers will be very similar, being different just in the
buttons at each controller. In one embodiment, the controller
includes a Universal Serial Bus (USB) connection for charging the
controller, Bluetooth for wireless communication with the console,
and buttons such as start, select and PS.
[0048] In one embodiment, the ball or sphere is 4 cm. in diameter,
but other sizes are also possible. Bigger sizes help with visual
recognition. A ball with a 5 cm. diameter provides about 55 percent
more pixels for image recognition than a 4 cm. ball.
[0049] FIGS. 1C-E depict different operational modes for the game
controller of FIGS. 1A-B. FIG. 1C shows a "reverse wand" operation,
where the ball section is located at the bottom of the controller,
and the top includes input buttons. In this configuration, the
controller can be used as an arcade flight stick by pivoting on the
sphere. In one embodiment, an inertial unit provides the angle of
the "stick" (controller) and the twist, and the top surface
includes a directional pad. In another embodiment, the top surface
holds removable plates to change button configuration, as described
below with respect to FIGS. 4A-4D. This mode of operation can be
used in firing, driving, flying games, etc.
[0050] In one embodiment, the controller includes buttons for the
index and middle finger in the reverse wand configuration. As a
result, two reverse wand controllers provide the same functionality
as a Sony DualShock.RTM.2 controller from Sony Computer
Entertainment America Inc.
[0051] FIG. 1D shows a controller behind held in a "pencil"
configuration. The ball faces the camera for visual identification,
and buttons in the body of the controller enable user input. This
mode can be use in games where the controller is a paint brush, a
flashlight, a pointer, a firing weapon, etc. FIG. 1E illustrate the
use of a controller in wand mode. In one embodiment, the wand
includes two thumb buttons at the top of the handle and a trigger
for the index finger, but other configurations are also possible.
The wand mode can be used as a magic-wand, a music director's
baton, a tennis racket, a hatchet or similar weapon, a tool such as
a pick, an umbrella, a rope, etc.
[0052] FIGS. 2A-2B shows other embodiments of a game controller
with a ball attached. The body of controllers in FIGS. 2A and 2B
are spherical like the attached balls. The controllers have
different button configurations and are intended for use in
different hands. In one embodiment, the controllers are identical,
and can be used either with the left or the right hand. The
controllers of FIGS. 2A and 2B are held in a "baseball"
configuration, that is, the controller is about the size of a
baseball or a tennis ball and is held as a baseball in the palm of
the hand. Similar to the configurations in FIGS. 1C to 1E, the
controllers in 2A and 2B can be held with the ball attachment
pointing in different directions, such as towards the camera, the
floor, or the ceiling.
[0053] FIGS. 3A-3B depict different embodiments of a ball-attached
game controller. The controllers are slimmer and designed for light
weight applications.
[0054] FIGS. 4A-D show an embodiment of a ball-attached game
controller with interchangeable face-plates. FIG. 4A shows a
controller, similar to the controllers in FIGS. 1A-B, but with
interchangeable face-plates. The face-plates for FIGS. 4B-4D can be
attached to the controller, either at the top or at the side. In
another embodiment, the sizes of the face plates are different for
the slots on the top and the side, and the face plates for the top
are not exchangeable with the face plates for the side. FIGS. 4B-4D
show a D-pad attachment, an action-buttons pad, and a touch pad,
respectively. The attachments include electrical connections and a
mechanical grip that snaps the attachments securely when placed on
the controller.
[0055] FIG. 5 shows a schematic diagram of a multiplayer
environment and the use of visual information to determine the
locations of the different controllers held by the players,
according to one embodiment. Image capture device 508 obtains an
image of playing field 518 and the image is analyzed to obtain the
location of ball-attached controllers C.sub.1, C.sub.2, C.sub.4 and
C.sub.5. Distances d.sub.z1, d.sub.z2, d.sub.z4, and d.sub.z5 are
estimated by analyzing the shape of the respective balls in the
captured image. Computing system 502, uses the obtained coordinates
and distances to produce representations of the players in screen
504, avatars 512a and 512b respectively. A typical distance for
good image recognition is about 10 ft (3 mtr). One advantage of
using visual recognition is that improvements in image capture and
image recognition can be included in the system without having to
change the controller.
[0056] FIGS. 6A-6D illustrate different embodiments for assigning a
geometric shape to a perceived shape from a captured image. FIG. 4A
shows some of the problems with determining where the "true"
geometric shape (i.e. the ball) given a captured image. Since the
ball is a sphere, the goal is to determine the circle that
corresponds to the ball in the image captured by the camera. There
are different ways of assigning a circle to a perceived shape, such
as the one in FIG. 6A, depending on the methodology. For example, a
circle inside the received shape could be selected in order to
assure that all pixels in the circle are pixels corresponding to
the ball, or a circle could be selected that would contain all the
shape pixels and the minimum amount of non-shape pixels.
Alternatively, the algorithm may focus on detecting the outside
curves delimiting the captured shape and then fit a circle that
approximates those curves.
[0057] In many cases, the number of pixels captured associated with
the ball is small. In one embodiment, a ball located at 10 ft. (3
mt.) generates an image where the radius of the circle is 4 pixels.
In other words, each pixel corresponds to a depth of 2.5 ft. If a
pixel is missed because of noise or because of an inaccurate
algorithm, then the location of the player jumps 2.5 ft. As a
result, pixel counting by itself does not provide an accurate
measure of depth. Additionally, if the ball gets occluded due to
the movement of the controller, only a partial image may be
captured by the camera. Curve fitting becomes critical to analyze
the perceived shape and determine the best location and shape of
the ball.
[0058] FIG. 6B illustrates estimating the center and the radius r
of the circle. The depth, also known herein as z, is related to the
area of the ball, and is proportional to 1/r. In one embodiment,
the method finds the pixels that correspond to the visual
identification of the ball. The pixels associated with the ball are
counted to determine the area, and then the center and the r are
calculated based on the size.
[0059] In another embodiment, the periphery of the shape in FIG. 6B
is analyzed to determine the curve surrounding the shape. The curve
is analyzed in order to determine the circle that best fits the
curve. In one embodiment, the circle chosen is the circle that
would have the smallest sum of the unique areas delimited by the
circle and the curve surrounding the perceived shape.
[0060] FIG. 6C illustrates the difficulty in finding an associated
circle given an imperfect shape. Visually inspecting the shape, it
can be inferred that only a partial section of the ball has been
captured. Doing a straight pixel count to determine the area would
not produce an accurate result. In one embodiment, the method
checks for the "fuzzy" boundaries around the edges, which may be
caused by shadows, light variations, etc., and determines the shape
of the outside curve. The perimeter curve of the shape is analyzed
to determine the center, also referred to herein as "centroid", and
to determine the radius that best fits the area and the outside
curve.
[0061] FIG. 6D illustrates the "fit the longest stick" method. As
previously described, the image is analyzed and a shape of the
captured ball is determined. The method determines the longest
straight segment, or "stick," that fits inside the shape. The
longest segment is then considered the diameter of the circle
associated with the ball.
[0062] FIG. 7 illustrates how to use subpixel analysis to find
pixels corresponding to the ball section in accordance with one
embodiment. In many display and image-acquisition systems are, the
pixel grid is divided into single-color regions that contribute to
the displayed or sensed color when viewed at a distance. In some
displays, such as LCD, LED, and plasma displays, these single-color
regions are separately addressable elements, which have come to be
known as subpixels. For example, LCDs typically divide each pixel
702 into three subpixels 704, 706, and 708.
[0063] In one embodiment, the pixel analysis focuses on just one
color, such as blue. In other embodiments, the analysis focuses on
the combination of two subpixels, improving accuracy but requiring
more computation. Additionally, the analysis of one pixel is not
constrained to analyzing the pixel, or the subpixels in the pixel,
and nearby pixels are analyzed to improve accuracy and reduce the
effects of noise or other conditions such as inconsistent
lighting.
[0064] FIG. 8 shows the effects of blurring an image to improve
shape detection according to one embodiment of the invention. The
image is taking with the camera slightly out of focus causing a
blurring effect on the ball, which causes the perceived area of the
ball to be bigger than an image taken without blurring. A larger
area means more pixels for analysis and improved accuracy.
[0065] FIG. 9 depicts the use of several consecutive captured
images to determine ball location according to one embodiment,
referred to herein as smoothing. In one embodiment, the captured
images are not analyzed in isolation. The information from one
image is compared with previously taken images. If the image-taking
frequency is high enough, consecutive images will be similar, even
after factoring the movement of the controller. As a result, the
information from previous images can be used to detect sudden
anomalous pixel variations, which are likely caused by noise, bad
lighting, ball occlusion, etc.
[0066] In one embodiment, the information from previous images is
weighted in inverse proportion to their age, that is, older images
are given smaller weights, as the information that they convey
becomes less relevant.
[0067] FIG. 10 illustrates one embodiment for taking an image from
a reduced area 156 of the playing field 152 to increase accuracy.
The computer system keeps track of the movement of the ball,
together with the controller attached to the ball, and has the
expectation that the ball will be in about the same place as the
last time an image was taken, assuming the video taking frequency
is adequate to allow for small movements of the controller between
images. In one embodiment, the video taking camera as zoom
capabilities and takes image 154 of reduced area 156 where the ball
was in the last image and a buffer area around the ball to allow
for movement of the controller. The image of the reduced area has
higher resolution and provides more pixels associated with the ball
for better location determination.
[0068] As a result, the field of play where the ball is present is
reduced when taking the image of the reduced area, but this can be
easily compensated by tracking the movement of the ball in order to
capture zoomed-in images centered around the last known position of
the ball.
[0069] In another embodiment, the camera is able to zoom-in only in
the center of the field of play. In this case, the zoom-in function
is only used when the ball is located towards the center of the
field of play. This will cause the resolution to be better when the
player is located around the center of the field of play and worse
when the ball is located in the periphery of the field of play.
[0070] FIG. 11 depicts image recognition of a ball with a small
number of pixels, according to one embodiment. As previously
described with respect to FIG. 6A, recognition of a ball when few
pixels are available can cause big changes in the perceived shape
when even one pixel is missed or miscalculated. The problem of
few-pixel availability can be aggravated when the ball moves across
pixel boundaries. In a first position 160 of the ball, the method
perceives the ball as having four pixels. In one embodiment, the
method determines that a pixel is associated with the color of the
ball when at least fifty percent of the pixel corresponds to the
ball, but other embodiments may use other percentages as the
threshold. As the ball moves to second position 162, the method
perceives 7 pixels associated with the ball. Because the ball
corresponds to a few pixels, the position of the ball in the pixel
grid is a factor under the scenario in FIG. 11. In addition, the
problem can be compounded with other factors such as noise and
rasterization.
[0071] One embodiment solves the small number of pixels problem by
using a higher resolution camera. FIG. 12 depicts one embodiment
for image recognition using a high resolution camera. Because the
ball includes a larger number of pixels, small movements of the
ball across the pixel grid will have a smaller impact on shape
recognition than when using a lower resolution camera.
[0072] FIGS. 13A-C illustrate ball detection using an illuminated
ring movable to face the camera in accordance with one embodiment.
Controller 170 has a ball section 172 attached for visual
recognition based on images taken with image capture device 180.
Ball section 172 includes an inner sphere or ball 174. Ball 174 has
a plurality of light sources 178a-n that form a visual ring facing
image capture device 180. In one embodiment, the light sources
correspond to the ends of optical wires that shine the light
received from the corresponding optic wire. In another embodiment,
the light sources correspond to LEDs.
[0073] Inside ball 174 is configured to move inside ball 172 in
order to substantially face capture device 180. In one embodiment,
ball 174 is suspended in a liquid to facilitate the movement. FIG.
13B shows the same controller 170 of FIG. 13A after the controller
has moved his orientation about 45 degrees. Although controller 170
has moved, inside ball 174 has rotated with respect to controller
170 so the illuminated ring still faces capture device 180. As a
result, the image captured will be a ring, which aids in
determining the location of the ball, as described below with
respect to FIGS. 15A-B.
[0074] In another embodiment, the ring can be illuminated with
different color lights to enhance image recognition, or to
differentiate different controllers in the field of play. In yet
another embodiment, more than one ring are available for
illumination, where only one ring is illuminated at one time, or
where a plurality of rings are illuminated at the same time for
image recognition. FIG. 13C illustrates a frontal view of the ball
section, as seen by image capture device 180.
[0075] FIGS. 14A-H illustrate detection of a distinguishable ring
in the ball section, according to one embodiment. FIG. 14A includes
controller 190 with ball 192 attached, which includes inside ball
194 with illuminated ring 196. Unlike the controllers of FIGS.
13A-C, the controllers in FIGS. 14A-C do not have a ball that moves
with respect to the controller. Thus, as the controller moves from
the substantially vertical position in FIG. 14A to a different
orientation, as in FIG. 14B, ring 196 goes from facing image
capture device 180 straight, to facing the image capture device at
an angle with respect to the line connecting the ball with capture
device 180. In FIG. 14A, the image captures an illuminated circle,
and in FIG. 14B, the image captures an elliptical ring. In most
controller positions where the ring is not facing the camera
straight, the image will only capture about half of the ring
because the other half section is hidden in the posterior
non-visible side of the ball.
[0076] FIG. 14C shows the image captured by the camera when the
controller is in the position shown in FIG. 14B. FIG. 14D
illustrates the effects of changing the orientation of the
controller with respect to the camera, according to different axis
x, y, and z. The controller at position 250 is facing the camera,
thus the camera only "sees" the ball. The rest of the positions
correspond to changing the orientation of the controller within a
different axis. This can be visualized by having a player holding
the controller aiming directly at the camera in position 250. Then
the player changes the position of the controller, just by rotating
the elbow in the x, y, or z direction.
[0077] As the controller turns in the x direction (horizontally), a
bigger part of the controller will be visible (the actual hand of
the player is ignored), and the ring will rotate until the
controller is oriented horizontally 256, and the ring will be
perceived sideways as a line. The similar effect can be observed
when the controller rotates in the y direction (vertically).
Movement in the z (depth) direction will cause the perceived ring
to change also. The effect of the size of the ball becoming smaller
as the ball moves away from the camera is ignored in FIG. 14D.
[0078] FIG. 14E shows the shape of the ring, as perceived by the
camera, according to the movement of the controller as discussed in
FIG. 14D. The perfect circle 250 shown when the ball faces the
camera gets distorted as the ball moves and becomes an ellipse,
where the small axis becomes smaller and smaller as the ring moves
further away from the position facing the camera.
[0079] It should be noted that an ellipse is a collection of points
in a plane such that the sum of the distances to two fixed points
is a constant. The two fixed points are called foci. If the two
foci coincide, then the ellipse is a circle. In other words, a
circle is a special case of an ellipse. The embodiments described
herein referring to an ellipse are designed to cover the case where
the ellipse is a circle, because the circle is just one form of an
ellipse, such as circle 250 of FIG. 14E.
[0080] FIG. 14F depicts a controller facing the camera and moving
away in the z direction. As expected, the ring becomes smaller as
the ball gets further away from the camera.
[0081] In another embodiment, the ball includes different
illuminated patterns, such as the three rings of FIG. 14G. FIG. 14H
shows a ball with two rings perpendicular to each other. In yet
another embodiment, the ball has an illuminated ring, such as the
one in FIG. 14E, however the ring has a different orientation when
the controller is aiming straight at the camera. The circle formed
by the illuminated ring is perpendicular to the camera, where the
camera would perceive a straight line when the controller is
oriented straight towards the camera, such as any of the rings
shown in FIG. 14H. In yet another embodiment, the ring is not
completely illuminated because the part of the ring facing the
controller would rarely be captured by the camera, resulting in
savings in manufacturing of the ring, as well as in battery
consumption. In one embodiment, the ring is only illuminated along
a 270 degrees arc of the ring, but other values are also
possible.
[0082] FIGS. 15A-B depicts a method to estimate a complete ring
area from a partial arc section. FIG. 15A shows a captured ring
350, where only about half of ring 352 has been detected, such as
when the ball is occluded. In general, it is easier to find the
center of an arc with partial information, than finding the center
of a circle with partial information. As described hereinabove with
respects to FIGS. 6A-6D, determining the center of a circle is not
a straightforward task with less than perfect information. On the
other hand, it is relatively easy to find the center of an arc with
information about half the arc, as in FIG. 15A.
[0083] By analyzing the curve corresponding to the ring, radius 354
can be estimated together with the center of the arc. FIG. 15B
shows a scenario where a small section 356 of the ring has been
captured. However, the same method used in FIG. 15A can be used to
determine a circle with a high level of accuracy. Although less
information is available, the analysis of the curve detected
produces accurate results because only a small number of circles
would fit this curve, and the variation between the circles is
small, that is, the circles produce similar values of r and centers
not far apart from each other.
[0084] In the case where the angle of the ring with respect to the
camera can change, such as the ones corresponding to FIGS. 14A-D,
the analysis is extended to cover ellipses. For example, given a
perceived ring such as the half ellipse 252 of FIG. 14E, the method
analyses the ellipse to estimate the long and the short axis of the
ellipse, as well as the center of the ellipse.
[0085] FIG. 16 shows and embodiment where the ball vibrates to
increase the perceived ball surface. As the ball vibrates, a longer
perceived area is captured by the camera. This method can be
combined with smoothing, such as the algorithm depicted in FIG. 9,
to improve location determination. Because the ball vibrates from
respect to each center, the comparison or averaging of consecutive
images will help determine the true center with higher
accuracy.
[0086] FIGS. 17A-B depict embodiments of a ball that can change
size or appearance to improve detection. FIG. 17A depicts a ball
that can change size. When player 450a is closer to camera 456
sitting atop display 458, ball 454a attached to controller 452 has
a predetermined size. When the player is in location 450b,
controller 452 and attached ball are farther away from the screen.
As the ball gets relatively smaller in the image captured by the
camera, determining the ball's location becomes harder. In order to
improve detection, ball 454b is expanded to improve accuracy. The
bigger ball translates into more pixels in the images captured,
making determining the location of the controller more accurate.
Several ways to inflate the ball are possible, such as inflation, a
motor, etc.
[0087] In one embodiment, controller 452 is in communication with
computing device 460 to convey the size of the ball. In another
embodiment, computing device 460 sends commands to the controller
to make the ball bigger as the number of pixels detected in the
ball become lower than a predetermined threshold.
[0088] FIG. 17B shows controller with ball 460 that can change,
modify or improve its appearance to improve detection depending on
the lighting conditions in the field of play. If the field of play
is nearby a source of light (natural or artificial), such as a
window that can receive light from sun 462, then visual detection
may be affected depending on the time of the day or night and the
amount of light in the field of play. The appearance of the ball
also is affected by the angle of impact from the sun rays. For
example, the appearance of the ball will be different if the
sunlight hits the ball at the front, back, or side. Similarly, lamp
464 (or the like) can affect visual detection depending on whether
the lamp is on or off.
[0089] In one embodiment, ball 460 includes a light source inside
that can be turned on or off to improve ball 460 visibility. The
light source can be turned on by the player or by the computer
system in communication with the controller including ball 460. In
another embodiment, ball 460 can include a clear shell. In another
embodiment, the shell can be frosted. Still further, the shell
(either clear or frosted), can take on any shade, color or texture.
For example, if the shell is frosted or has a shade, then the ball
460 can be made to appear darker when not illuminated. An example
shade can be a gray, black, silver, or combinations of colors, so
long as the color or shade provides good differentiating contrast,
when placed in a particular environment. The shell can be made from
many materials, such as plastics, rubber, glass, foam, molded
materials, etc. And, these materials can take on any color, whether
applied, dyed or molded.
[0090] Still further, the light source inside ball 460 can make
ball 460 illuminated in different colors, such as white or yellow,
while other colors are also possible. The illuminated ball can
improve detection in low ambient light conditions, while a darker
color ball improves detection in situations with bright light.
[0091] FIG. 18 shows an embodiment of game controller 470 with a
ball section 472 enclosed in shell 478. Shell 478 lets light go
thorough so the ball can be detected visually. In one embodiment,
shell 478 lets light 474 come out in the direction from the ball
towards the camera, but shell 478 does not let light 476 coming
from the outside to go through. This way, there is less
interference with the illuminated ball inside.
[0092] In another embodiment, shell 478 can selectively filter the
light passing thorough, such as for example letting blue light go
through in order to identify a blue ball.
[0093] FIGS. 19A-B describe a controller with sensors for improving
movement tracking, according to one embodiment. Different
embodiments include different combinations of sensors, such as
magnetometers, accelerometers, gyroscopes, etc.
[0094] An accelerometer is a device for measuring acceleration and
gravity induced reaction forces. Single and multiple axis models
are available to detect magnitude and direction of the acceleration
in different directions. The accelerometer is used to sense
inclination, vibration, and shock. In one embodiment, three
accelerometers are used to provide the direction of gravity, which
gives an absolute reference for 2 angles (world-space pitch and
world-space roll). Controllers can suffer accelerations exceeding 5
g, therefore accelerometers able to operate with forces exceeding 5
g are used inside controller 550.
[0095] A magnetometer measures the strength and direction of the
magnetic field in the vicinity of the controller. In one
embodiment, three magnetometers 552 are used within the controller,
ensuring an absolute reference for the world-space yaw angle. The
magnetometer is designed to span the earth magnetic field, which is
.+-.80 microtesla. Magnetometers are affected by metal, and provide
a yaw measurement that is monotonic with actual yaw. The magnetic
field may be warped due to metal in the environment, which causes a
warp in the yaw measurement. If necessary, this warp can be
calibrated using information from the gyros (see below) or the
camera. In one embodiment, accelerometer 554 is used together with
magnetometer 552 to obtain the inclination and azimuth of the
controller.
[0096] A gyroscope is a device for measuring or maintaining
orientation, based on the principles of angular momentum. In one
embodiment, three gyroscopes provide information about movement
across the respective axis (x, y and z) based on inertial sensing.
The gyroscopes help in detecting fast rotations. However, the
gyroscopes can drift overtime without the existence of an absolute
reference. This requires, resetting the gyroscopes periodically,
which can be done using other available information, such as visual
tracking of ball 558, accelerometer, magnetometer, etc. A hand-held
device can rotate faster than 500 degrees/sec, so a gyroscopes with
an spec of more than 1000 degrees/sec is recommended, but smaller
values are also possible.
[0097] The information from the different sources can be combined
for improved location and orientation detection. For example, if
the ball disappears from view, the accelerometer's orientation
sensing is used to detect that the controller is facing away from
the camera. In one embodiment, controller 550 includes a speaker to
provide audio feedback to the player. For example, the controller
can produce a beep when the ball is not visible by the camera,
prompting the player to orientate the controller in the right
direction, or to come back into the field of play.
[0098] In the embodiment shown in FIG. 19B, the visual and
sensor-originated information from several frames is analyzed to
determine the location of the controller as well as the
controller's orientation. By analyzing the information from several
frames, the sensor information related to movement and orientation
of the controller is "smoothed" over several frames. Once the
trajectory of the ball is determined over several frames, the
sensor information is analyzed to find the corresponding
orientation of the controller that produces the given trajectory
given the corresponding sensor information for those frames.
[0099] FIG. 20 depicts using different sources of information to
assess controller position in accordance with one embodiment.
Controller 570 includes a ball section attached, as well as
accelerometers, as previously described with respect to FIG. 19.
The computing system uses visual tracking of the ball in controller
570. When the ball gets occluded, such as when the controller
follows trajectory 582 that causes occlusion when the ball is
behind the player's head, the system uses dead reckoning. Dead
reckoning (DR) is the process of estimating a current position
based upon a previously determined position, or fix, and advancing
that position based upon known speed, elapsed time, and course.
[0100] As the controller's ball follows path 582, the computing
system tracks the controller under curve 580. Once the ball gets
occluded, the accelerometers are reset and the system begins using
dead reckoning. It should be noted, that dead reckoning loses
accuracy over time, thus complementing dead reckoning with other
location information is desirable for accurate tracking. Data from
the accelerometers is always being captured, but may not be always
used by the system.
[0101] Dead reckoning is used while the ball is occluded (region
574). Once the ball is back on sight, visual tracking takes over in
region 578. In one embodiment, dead reckoning can be combined at
times with visual tracking, such as the region when the ball is
coming out of invisibility and visual information is still not very
accurate because of partial occlusion, or because of the lack of
visual history to track the ball's movement.
[0102] FIGS. 21A-C describe the use of an input wheel in the
controller to initiate computer actions, according to one
embodiment. Controller orientation is combined with wheel movement
to generate actions in the computing system. For example, a player
may place the controller in the x, y, or z direction and then
rotate the wheel, causing an icon in the screen to move in that
direction. In fact, the controller does not have to be orientated
along an axis, and any orientation can cause a corresponding
movement on the screen. For example, a controller placed at 45
degrees between the x and y axis, will cause an icon on display 654
to move in that direction. Additionally, the wheel can be used to
navigate menus. For example, to move vertically or horizontally
across menus, according to the orientation of the controller. FIG.
21A shows controller 650 including wheel 658A in a vertical or
longitudinal orientation. FIG. 21B shows controller 670 including
wheel 672 in a horizontal or latitudinal orientation. The top part
of wheel 672 is used by the player to input commands. FIG. 21C
shows controller 674 that also includes wheel 676 in a horizontal
or latitudinal orientation. Wheel 676 wraps around the controller
and moves perpendicularly 680 relative to the holding portion 678
of the body of the controller. The complete circumference of wheel
676 is available to the user which can operate the wheel from the
top, the sides, the bottom, or any other angle, and with the
possibility of operating the wheel using different fingers.
[0103] FIG. 22 illustrates hardware and user interfaces that may be
used to determine controller location, in accordance with one
embodiment of the present invention. FIG. 22 schematically
illustrates the overall system architecture of the Sony.RTM.
Playstation 3.RTM. entertainment device, a console that may be
compatible for implementing a three-dimensional controller locating
system in accordance with one embodiment of the present invention.
A system unit 1400 is provided, with various peripheral devices
connectable to the system unit 1400. The system unit 1400
comprises: a Cell processor 1428; a Rambus.RTM. dynamic random
access memory (XDRAM) unit 1426; a Reality Synthesizer graphics
unit 1430 with a dedicated video random access memory (VRAM) unit
1432; and an I/O bridge 1434. The system unit 1400 also comprises a
Blu Ray.RTM. Disk BD-ROM.RTM. optical disk reader 1440 for reading
from a disk 1440a and a removable slot-in hard disk drive (HDD)
1436, accessible through the I/O bridge 1434. Optionally the system
unit 1400 also comprises a memory card reader 1438 for reading
compact flash memory cards, Memory Stick.RTM. memory cards and the
like, which is similarly accessible through the I/O bridge
1434.
[0104] The I/O bridge 1434 also connects to six Universal Serial
Bus (USB) 2.0 ports 1424; a gigabit Ethernet port 1422; an IEEE
802.11b/g wireless network (Wi-Fi) port 1420; and a Bluetooth.RTM.
wireless link port 1418 capable of supporting of up to seven
Bluetooth connections.
[0105] In operation, the I/O bridge 1434 handles all wireless, USB
and Ethernet data, including data from one or more game controllers
1402-1403. For example when a user is playing a game, the I/O
bridge 1434 receives data from the game controller 1402-1403 via a
Bluetooth link and directs it to the Cell processor 1428, which
updates the current state of the game accordingly.
[0106] The wireless, USB and Ethernet ports also provide
connectivity for other peripheral devices in addition to game
controllers 1402-1403, such as: a remote control 1404; a keyboard
1406; a mouse 1408; a portable entertainment device 1410 such as a
Sony Playstation Portable.RTM. entertainment device; a video camera
such as an EyeToy.RTM. video camera 1412; a microphone headset
1414; and a microphone 1415. Such peripheral devices may therefore
in principle be connected to the system unit 1400 wirelessly; for
example the portable entertainment device 1410 may communicate via
a Wi-Fi ad-hoc connection, whilst the microphone headset 1414 may
communicate via a Bluetooth link.
[0107] The provision of these interfaces means that the Playstation
3 device is also potentially compatible with other peripheral
devices such as digital video recorders (DVRs), set-top boxes,
digital cameras, portable media players, Voice over IP telephones,
mobile telephones, printers and scanners.
[0108] In addition, a legacy memory card reader 1416 may be
connected to the system unit via a USB port 1424, enabling the
reading of memory cards 1448 of the kind used by the
Playstation.RTM. or Playstation 2.RTM. devices.
[0109] The game controllers 1402-1403 are operable to communicate
wirelessly with the system unit 1400 via the Bluetooth link, or to
be connected to a USB port, thereby also providing power by which
to charge the battery of the game controllers 1402-1403. Game
controllers 1402-1403 can also include memory, a processor, a
memory card reader, permanent memory such as flash memory, light
emitters such as LEDs or infrared lights, microphone and speaker
for ultrasound communications, an acoustic chamber, a digital
camera, an internal clock, a recognizable shape such as a spherical
section facing the game console, and wireless communications using
protocols such as Bluetooth.RTM., WiFi.TM., etc.
[0110] Game controller 1402 is a controller designed to be used
with two hands, and game controller 1403 is a single-hand
controller with a ball attachment, as previously described in FIGS.
1A-4A. In addition to one or more analog joysticks and conventional
control buttons, the game controller is susceptible to
three-dimensional location determination. Consequently gestures and
movements by the user of the game controller may be translated as
inputs to a game in addition to or instead of conventional button
or joystick commands. Optionally, other wirelessly enabled
peripheral devices such as the Playstation.TM. Portable device may
be used as a controller. In the case of the Playstation.TM.
Portable device, additional game or control information (for
example, control instructions or number of lives) may be provided
on the screen of the device. Other alternative or supplementary
control devices may also be used, such as a dance mat (not shown),
a light gun (not shown), a steering wheel and pedals (not shown) or
bespoke controllers, such as a single or several large buttons for
a rapid-response quiz game (also not shown).
[0111] The remote control 1404 is also operable to communicate
wirelessly with the system unit 1400 via a Bluetooth link. The
remote control 1404 comprises controls suitable for the operation
of the Blu Ray.TM. Disk BD-ROM reader 1440 and for the navigation
of disk content.
[0112] The Blu Ray.TM. Disk BD-ROM reader 1440 is operable to read
CD-ROMs compatible with the Playstation and PlayStation 2 devices,
in addition to conventional pre-recorded and recordable CDs, and
so-called Super Audio CDs. The reader 1440 is also operable to read
DVD-ROMs compatible with the Playstation 2 and PlayStation 3
devices, in addition to conventional pre-recorded and recordable
DVDs. The reader 1440 is further operable to read BD-ROMs
compatible with the Playstation 3 device, as well as conventional
pre-recorded and recordable Blu-Ray Disks.
[0113] The system unit 1400 is operable to supply audio and video,
either generated or decoded by the Playstation 3 device via the
Reality Synthesizer graphics unit 1430, through audio and video
connectors to a display and sound output device 1442 such as a
monitor or television set having a display 1444 and one or more
loudspeakers 1446. The audio connectors 1450 may include
conventional analogue and digital outputs whilst the video
connectors 1452 may variously include component video, S-video,
composite video and one or more High Definition Multimedia
Interface (HDMI) outputs. Consequently, video output may be in
formats such as PAL or NTSC, or in 720p, 1080i or 1080p high
definition.
[0114] Audio processing (generation, decoding and so on) is
performed by the Cell processor 1428. The Playstation 3 device's
operating system supports Dolby.RTM. 5.1 surround sound, Dolby.RTM.
Theatre Surround (DTS), and the decoding of 7.1 surround sound from
Blu-Ray.RTM. disks.
[0115] In the present embodiment, the video camera 1412 comprises a
single charge coupled device (CCD), an LED indicator, and
hardware-based real-time data compression and encoding apparatus so
that compressed video data may be transmitted in an appropriate
format such as an intra-image based MPEG (motion picture expert
group) standard for decoding by the system unit 1400. The camera
LED indicator is arranged to illuminate in response to appropriate
control data from the system unit 1400, for example to signify
adverse lighting conditions. Embodiments of the video camera 1412
may variously connect to the system unit 1400 via a USB, Bluetooth
or Wi-Fi communication port. Embodiments of the video camera may
include one or more associated microphones and also be capable of
transmitting audio data. In embodiments of the video camera, the
CCD may have a resolution suitable for high-definition video
capture. In use, images captured by the video camera may for
example be incorporated within a game or interpreted as game
control inputs. In another embodiment the camera is an infrared
camera suitable for detecting infrared light.
[0116] In general, in order for successful data communication to
occur with a peripheral device such as a video camera or remote
control via one of the communication ports of the system unit 1400,
an appropriate piece of software such as a device driver should be
provided. Device driver technology is well-known and will not be
described in detail here, except to say that the skilled man will
be aware that a device driver or similar software interface may be
required in the present embodiment described.
[0117] FIG. 23 illustrates additional hardware that may be used to
process instructions, in accordance with one embodiment of the
present invention. Cell processor 1428 has an architecture
comprising four basic components: external input and output
structures comprising a memory controller 1560 and a dual bus
interface controller 1570A, B; a main processor referred to as the
Power Processing Element 1550; eight co-processors referred to as
Synergistic Processing Elements (SPEs) 1510A-H; and a circular data
bus connecting the above components referred to as the Element
Interconnect Bus 1580. The total floating point performance of the
Cell processor is 218 GFLOPS, compared with the 6.2 GFLOPs of the
Playstation 2 device's Emotion Engine.
[0118] The Power Processing Element (PPE) 1550 is based upon a
two-way simultaneous multithreading Power 1470 compliant PowerPC
core (PPU) 1555 running with an internal clock of 3.2 GHz. It
comprises a 512 kB level 2 (L2) cache and a 32 kB level 1 (L1)
cache. The PPE 1550 is capable of eight single position operations
per clock cycle, translating to 25.6 GFLOPs at 3.2 GHz. The primary
role of the PPE 1550 is to act as a controller for the Synergistic
Processing Elements 1510A-H, which handle most of the computational
workload. In operation the PPE 1550 maintains a job queue,
scheduling jobs for the Synergistic Processing Elements 1510A-H and
monitoring their progress. Consequently each Synergistic Processing
Element 1510A-H runs a kernel whose role is to fetch a job, execute
it and synchronized with the PPE 1550.
[0119] Each Synergistic Processing Element (SPE) 1510A-H comprises
a respective Synergistic Processing Unit (SPU) 1520A-H, and a
respective Memory Flow Controller (MFC) 1540A-H comprising in turn
a respective Dynamic Memory Access Controller (DMAC) 1542A-H, a
respective Memory Management Unit (MMU) 1544A-H and a bus interface
(not shown). Each SPU 1520A-H is a RISC processor clocked at 3.2
GHz and comprising 256 kB local RAM 1530A-H, expandable in
principle to 4 GB. Each SPE gives a theoretical 25.6 GFLOPS of
single precision performance. An SPU can operate on 4 single
precision floating point members, 4 32-bit numbers, 8 16-bit
integers, or 16 8-bit integers in a single clock cycle. In the same
clock cycle it can also perform a memory operation. The SPU 1520A-H
does not directly access the system memory XDRAM 1426; the 64-bit
addresses formed by the SPU 1520A-H are passed to the MFC 1540A-H
which instructs its DMA controller 1542A-H to access memory via the
Element Interconnect Bus 1580 and the memory controller 1560.
[0120] The Element Interconnect Bus (EIB) 1580 is a logically
circular communication bus internal to the Cell processor 1428
which connects the above processor elements, namely the PPE 1550,
the memory controller 1560, the dual bus interface 1570A,B and the
8 SPEs 1510A-H, totaling 12 participants. Participants can
simultaneously read and write to the bus at a rate of 8 bytes per
clock cycle. As noted previously, each SPE 1510A-H comprises a DMAC
1542A-H for scheduling longer read or write sequences. The EIB
comprises four channels, two each in clockwise and anti-clockwise
directions. Consequently for twelve participants, the longest
step-wise data-flow between any two participants is six steps in
the appropriate direction. The theoretical peak instantaneous EIB
bandwidth for 12 slots is therefore 96B per clock, in the event of
full utilization through arbitration between participants. This
equates to a theoretical peak bandwidth of 307.2 GB/s (gigabytes
per second) at a clock rate of 3.2 GHz.
[0121] The memory controller 1560 comprises an XDRAM interface
1562, developed by Rambus Incorporated. The memory controller
interfaces with the Rambus XDRAM 1426 with a theoretical peak
bandwidth of 25.6 GB/s.
[0122] The dual bus interface 1570A,B comprises a Rambus
FlexIO.RTM. system interface 1572A,B. The interface is organized
into 12 channels each being 8 bits wide, with five paths being
inbound and seven outbound. This provides a theoretical peak
bandwidth of 62.4 GB/s (36.4 GB/s outbound, 26 GB/s inbound)
between the Cell processor and the I/O Bridge 700 via controller
170A and the Reality Simulator graphics unit 200 via controller
170B.
[0123] Data sent by the Cell processor 1428 to the Reality
Simulator graphics unit 1430 will typically comprise display lists,
being a sequence of commands to draw vertices, apply textures to
polygons, specify lighting conditions, and so on.
[0124] FIG. 24 shows flow chart 2400 describing an embodiment for a
method to determine a location in a field of play of a
ball-attached game controller. In operation 2402, the method
obtains an image of the field of play where the game controller is
present, and then finds pixels in the image associated with the
ball connected to the game controller. In one embodiment, the image
is scanned to find pixels that correspond to the color of the ball,
and in another embodiment, subpixels analysis is used to find
pixels associated with the ball, as previously described with
respect to FIG. 7.
[0125] In operation 2406, the method establishes an area
encompassing the pixels that were found. A geometric shape is
determined in operation 2408 based on the area associated with the
ball. See FIGS. 6A-6D, 9, and 12 for different embodiments of
methods to perform area recognition. Once the geometric shape is
determined, the method, in operation 2410, calculates the location
of the controller based on the geometric shape, where the center of
the geometric shape indicates the horizontal and vertical location
of the controller, and the size of the geometric shape determines
the depth of the controller within the field of play. The
calculated location is stored in a memory associated with the
computer in operation 2412, and the computer drives an action based
on the stored location in operation 2414.
[0126] FIG. 25 includes a flow chart for a method to determine a
location in a field of play of a ball with a distinguishable ring,
according to one embodiment. This method is similar to the method
previously described with respect to FIG. 24, but the method of
FIG. 25 adds new considerations regarding the changes in shape of
the ring as the controller moves within the three-dimensional
space.
[0127] In operation 2502, the method obtains an image of the field
of play where the game controller is present, as seen in FIG. 5.
The image is scanned in operation 2504 to find pixels associated
with a ring in the ball section connected to the game controller.
See FIGS. 13A-15B for different embodiments related to location
determination based on the ring in the ball attached to the
controller.
[0128] In operation 2506, the method establishes an area
encompassing the pixels found in operation 2504, and, in operation
2508, the method determines an ellipse based on the area associated
with the ring. The location of the controller is calculated, in
operation 2510, based on the ellipse. The center of the ellipse
indicates the horizontal and vertical location of the controller,
and the size of the ellipse determines the depth of the controller
within the field of play. The location is stored, during operation
2212, in a memory associated with the computer. The computer drives
an action in response to the location stored in operation 2514.
[0129] Embodiments of the present invention may be practiced with
various computer system configurations including hand-held devices,
microprocessor systems, microprocessor-based or programmable
consumer electronics, minicomputers, mainframe computers and the
like. The invention can also be practiced in distributed computing
environments where tasks are performed by remote processing devices
that are linked through a wire-based or wireless network.
[0130] With the above embodiments in mind, it should be understood
that the invention can employ various computer-implemented
operations involving data stored in computer systems. These
operations are those requiring physical manipulation of physical
quantities. Any of the operations described herein that form part
of the invention are useful machine operations. The invention also
relates to a device or an apparatus for performing these
operations. The apparatus can be specially constructed for the
required purpose, or the apparatus can be a general-purpose
computer selectively activated or configured by a computer program
stored in the computer. In particular, various general-purpose
machines can be used with computer programs written in accordance
with the teachings herein, or it may be more convenient to
construct a more specialized apparatus to perform the required
operations.
[0131] The invention can also be embodied as computer readable code
on a computer readable medium. The computer readable medium is any
data storage device that can store data, which can be thereafter be
read by a computer system. Examples of the computer readable medium
include hard drives, network attached storage (NAS), read-only
memory, random-access memory, CD-ROMs, CD-Rs, CD-RWs, magnetic
tapes and other optical and non-optical data storage devices. The
computer readable medium can include computer readable tangible
medium distributed over a network-coupled computer system so that
the computer readable code is stored and executed in a distributed
fashion.
[0132] Although the method operations were described in a specific
order, it should be understood that other housekeeping operations
may be performed in between operations, or operations may be
adjusted so that they occur at slightly different times, or may be
distributed in a system which allows the occurrence of the
processing operations at various intervals associated with the
processing, as long as the processing of the overlay operations are
performed in the desired way.
[0133] Although the foregoing invention has been described in some
detail for purposes of clarity of understanding, it will be
apparent that certain changes and modifications can be practiced
within the scope of the appended claims. Accordingly, the present
embodiments are to be considered as illustrative and not
restrictive, and the invention is not to be limited to the details
given herein, but may be modified within the scope and equivalents
of the appended claims.
* * * * *