U.S. patent application number 09/801441 was filed with the patent office on 2002-01-24 for method and apparatus for video surveillance with defined zones.
Invention is credited to Broemmelsiek, Raymond M., Scott, Mark A..
Application Number | 20020008758 09/801441 |
Document ID | / |
Family ID | 22692026 |
Filed Date | 2002-01-24 |
United States Patent
Application |
20020008758 |
Kind Code |
A1 |
Broemmelsiek, Raymond M. ;
et al. |
January 24, 2002 |
Method and apparatus for video surveillance with defined zones
Abstract
In the field of motion video object tracking, environmental
noise and other such sources of movement can lead to false tracking
and tracking of unimportant objects. The present invention uses
user-defined exclusion regions within a motion video camera's field
of view to ignore the origination of object track data. Therefore,
the user defines in advance, those regions that may generate false
alarms within a motion video camera's field of view. The use of
user-defined zones in conjunction with object detection and
tracking techniques provides a video surveillance system that has
greater object tracking accuracy than existing systems.
Inventors: |
Broemmelsiek, Raymond M.;
(San Diego, CA) ; Scott, Mark A.; (San Diego,
CA) |
Correspondence
Address: |
Rick F. Comoglio
Sensormatic Electronics Corporation
951 Yamato Road
Boca Raton
FL
33431-0700
US
|
Family ID: |
22692026 |
Appl. No.: |
09/801441 |
Filed: |
March 7, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60188171 |
Mar 10, 2000 |
|
|
|
Current U.S.
Class: |
348/143 ;
348/155; 348/E7.09 |
Current CPC
Class: |
G08B 13/19686 20130101;
G01S 11/12 20130101; G01S 3/7864 20130101; G01S 5/16 20130101; H04N
7/188 20130101 |
Class at
Publication: |
348/143 ;
348/155 |
International
Class: |
H04N 007/18 |
Claims
1. A method for defining a control zone in a field of view of a
motion video camera, said method comprising the steps of:
displaying motion video data representative of the field of view of
the motion video camera; receiving indication of a control zone
type; and receiving indication of a control zone size within the
field of view of the motion video camera.
2. The method according to claim 1 further including the step of
displaying graphics representative of the control zone size in
association with the field of view and the motion video data.
3. The method according to claim 1 wherein the control zone type is
selected from the group consisting of tracking, black-out,
exclusion, entry and privacy.
4. A video surveillance method executed according to the control
zone defined in claim 1, said method comprising the steps of: (a)
detecting movement in a field of view of the motion video camera;
(b) determining if a moving object is in a tracking origination
zone; (c) defining the moving object if the moving object is in a
tracking origination zone; and (d) tracking the defined moving
object.
5. The video surveillance method according to claim 4 further
comprising the steps of: (e) determining if the defined moving
object has entered a new control zone type; (f) determining if the
new control zone type is a tracking continuation zone; and (g)
repeating step (d) to (f) if the new control zone type is a
tracking continuation zone.
6. The video surveillance method according to claim 4 further
comprising the steps of: (e) determining if the defined moving
object has entered a new control zone type; (f) determining if the
new control zone type is a tracking continuation zone; and (g)
ceasing tracking of the defined moving object if the new control
zone type is not a tracking continuation zone.
7. The video surveillance method according to claim 4 wherein the
control zone type is selected from the group consisting of
tracking, black-out, exclusion, entry and privacy.
8. The video surveillance method according to claim 7 wherein a
tracking zone is a tracking origination zone and a tracking
continuation zone and defines a region in which motion is monitored
in the field of view of the motion video camera.
9. The video surveillance method according to claim 7 wherein a
privacy zone only monitors movement.
10. The video surveillance method according to claim 7 wherein an
exclusion zone is a tracking continuation zone.
11. The video surveillance method according to claim 7 wherein an
entry zone is a tracking origination zone and a tracking
continuation zone.
12. The video surveillance method according to claim 7 wherein a
black-out zone is not monitored for movement.
13. A system for defining control zones of different types in a
field of view of a motion video camera, said system comprising: a
database containing a description for each of a plurality of
control zone types; means for defining a control zone in a selected
area of the field of view of the motion video camera, said control
zone being of a type selected from one of said plurality of control
zone types in said database; and means for displaying a received
motion video signal from the motion video camera including an
indication of said defined control zone.
14. The system according to claim 13 wherein said means for
displaying includes means for providing a graphical representation
of a size of said selected area of the field of view with the
received motion video signal.
15. A video surveillance system using a motion video camera having
control zones in the field of view thereof as defined in claim 13,
said system comprising: means for detecting movement in the field
of view of the motion video camera; means for determining a current
control zone of the moving object; means for defining the moving
object dependent on the current control zone of the moving object;
and means for performing a tracking operation the defined moving
object dependent on a control zone type of the current control
zone.
16. A computer readable medium having stored thereon
computer-executable instructions for defining a control zone in a
field of view of a motion video camera performing the steps
comprising: displaying motion video data representative of the
field of view of the motion video camera; receiving indication of a
control zone type; and receiving indication of a control zone size
within the field of view of the motion video camera.
17. The computer readable medium according to claim 16 further
including the step of displaying graphics representative of the
control zone size in association with the motion video data.
18. The computer readable medium according to claim 16 wherein the
control zone type is selected from the group consisting of
tracking, black-out, exclusion, entry and privacy.
19. A computer readable medium having stored thereon
computer-executable instructions for executing motion video camera
surveillance according to the control zone defined in claim 16
performing the steps comprising: (a) detecting movement in a field
of view of a motion video camera; (b) determining if a moving
object is in a tracking origination zone; (c) defining the moving
object if the moving object is in a tracking origination zone; and
(d) tracking the defined moving object.
20. The computer readable medium according to claim 19 further
comprising the steps of: (e) determining if the defined moving
object has entered a new control zone type; (f) determining if the
new control zone type is a tracking continuation zone; and (g)
repeating step (d) to (f) if the new control zone type is a
tracking continuation zone.
21. The computer readable medium according to claim 19 further
comprising the steps of: (e) determining if the defined moving
object has entered a new control zone type; (f) determining if the
new control zone type is a tracking continuation zone; and (g)
ceasing tracking of the defined moving object if the new control
zone type is not a tracking continuation zone.
22. The computer readable medium according to claim 19 wherein the
control zone type is selected from the group consisting of
tracking, black-out, exclusion, entry and privacy.
23. The computer readable medium according to claim 22 wherein a
tracking zone is a tracking origination zone and a tracking
continuation zone and defines a region in which motion is monitored
in the field of view of the motion video camera.
24. The computer readable medium according to claim 22 wherein a
privacy zone only monitors movement.
25. The computer readable medium according to claim 22 wherein an
exclusion zone is a tracking continuation zone.
26. The computer readable medium according to claim 22 wherein an
entry zone is a tracking origination zone and a tracking
continuation zone.
27. The computer readable medium according to claim 22 wherein a
black-out zone is not monitored for movement.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of United States
provisional patent application Ser. No. 60/188,171 filed on Mar.
10, 2000. United States Patent applications, also claiming the
benefit of U.S. Provisional application Ser. No. 60/188,171, and
entitled "Method and Apparatus for Object Tracking and Detection"
and "Method and Apparatus for Object Surveillance with a Movable
Camera" were filed concurrently herewith.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of video
surveillance systems using motion video cameras.
BACKGROUND OF THE INVENTION
[0003] There are several shortcomings in current video surveillance
systems that need to be overcome for widespread use of automatic
detection and collection of relevant video data in response to
scene stimulus without the need of a human operator present. When
viewing a scene from a video camera a large amount of data is
generated. The vast amount of data created produces a data
reduction problem. Automatically detecting and accurately and
reliably collecting image information of a moving object using a
motion video camera is a difficult task. This task is made even
more difficult when trying to detect, track and maintain camera
line-of-sight using a single motion video camera without requiring
human intervention.
[0004] U.S. Pat. No. 5,473,369 (Abe) describes the use of a camera
to detect and track a moving object without using conventional
block matching. In the system described in Abe single object
tracking is performed only after an object is placed within a frame
on a screen; however, there is no user input device for manual
target selection Moreover, Abe does not provide for camera movement
to maintain line-of-site.
[0005] Other prior art solutions provide for image stabilization
for a camera in arbitrary motion without object tracking
functionality. U.S. Pat. No. 5,629,988 (Burt) teaches electronic
stabilization of a sequence of images with respect to one another
but provides no tracking facility.
[0006] Still other prior art solutions control camera movement to
maintain line-of-sight between camera and object but lack arbitrary
motion compensation or do not provide for automatic and user
selected object tracking. U.S. Pat. No. 5,434,621 (Yu) teaches a
method for automatic zooming and automatic tracking of an object
using a zoom lens but does not provide for reorienting the camera's
line-of-sight.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide a video
surveillance method and system having increased accuracy.
[0008] It is an object of the present invention to provide a method
and system for reducing false alarms in motion video object
detection and surveillance.
[0009] It is an object of the present invention to provide a method
and system for identifying user-defined zones to control motion
video tracking.
[0010] In accordance with one aspect of the present invention there
is provided a method for defining a control zone in a field of view
of a motion video camera, said method comprising the steps of:
displaying motion video data representative of the field of view of
the motion video camera; receiving indication of a control zone
type; and receiving indication of a control zone size within the
field of view of the motion video camera.
[0011] In accordance with another aspect of the present invention
there is provided a system for defining control zones of different
types in a field of view of a motion video camera, said system
comprising: a database containing a description for each of a
plurality of control zone types; means for defining a control zone
in a selected area of the field of view of the motion video camera,
said control zone being of a type selected from one of said
plurality of control zone types in said database; and means for
displaying a received motion video signal from the motion video
camera including an indication of said defined control zone.
[0012] In accordance with a further aspect of the present invention
there is provided a computer readable medium having stored thereon
computer-executable instructions for defining a control zone in a
field of view of a motion video camera performing the steps
comprising: displaying motion video data representative of the
field of view of the motion video camera; receiving indication of a
control zone type; and receiving indication of a control zone size
within the field of view of the motion video camera.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is an exemplary configuration of a video surveillance
system having user-defined zones according to an embodiment of the
present invention;
[0014] FIG. 2 shows an exemplary field of view for a camera
highlighting user-defined zones according to the present
invention;
[0015] FIG. 3 is a system diagram of a zone defining processing
system the video surveillance system of FIG. 1 according to an
embodiment of the present invention;
[0016] FIG. 4 is a flow chart illustrating a method of identifying
user-defined zones according to the present invention; and
[0017] FIG. 5 is a flow chart illustrating a general method for
video surveillance using the user-defined zones identified by the
method in FIG. 4.
DETAILED DESCRIPTION
[0018] Object tracks, derived from motion video data, are a very
useful way to automatically detect alarm conditions within a
camera's field of view for purposes such as security and
surveillance. However, in the field of motion video object
tracking, environmental noise and other such sources of movement
can lead to false tracking and tracking of unimportant objects such
as leaves falling from a tree.
[0019] The present invention uses user-defined regions within a
motion video camera's field of view to ignore the origination of
object track data but allow tracking of objects already being
tracked before they entered that region. Therefore, the user
defines in advance those regions that may generate false alarms
within a motion video camera's field of view. The use of
user-defined zones in conjunction with object detection and
tracking techniques provides a video surveillance system that has
greater object tracking accuracy than existing systems.
[0020] FIG. 1 illustrates a video surveillance system 100 according
to an embodiment of the present invention. A motion video camera
108 has a field of view 118. A computer 102 receives and processes
a video signal 112 from the motion video camera 108 and performs
object tracking and detection to determine if there was movement in
the field of view 118. The computer 102 contains a zone defining
processing system (FIG. 3) for defining surveillance zones in the
camera's 108 field of view.
[0021] For a moveable motion video camera 108, the computer 102
generates a control signal 114 for servo controlled pan-tilt-zoom
assembly 110. The control signal 114 is based on the current
position of the servo controlled pan-tilt-zoom assembly 110 and
information contained in the video signal 112. Such movement allows
the motion video camera 108 to capture an object of interest in
greater detail or improve the camera's 108 line of sight with the
object of interest. The object detection and tracking techniques
that are used can be, for example, those taught in Applicant's
related applications entitled "Method and Apparatus for Object
Tracking and Detection" and "Method and Apparatus for Remote Object
Tracking and Detection", filed concurrently herewith, both of which
are incorporated herein by reference.
[0022] Object detection may be accomplished using any number of
methods for image segmentation known in the art. For example,
motion detection may be performed by frame differencing sequential
pairs of video frames and applying thresholding techniques thereby
yielding pixels within the processed image that reflect motion of
objects with the field of view of the camera 108. Additional image
processing techniques such as centroid analysis may then be applied
to remove spurious motion. Kalman filtering may be applied over
time to further remove random motion and to estimate motion of
objects for the purpose of anticipating camera 108 repositioning
and maintaining tracking when moving objects are temporarily
occluded by stationary ones. Object tracking and detection is
discussed in greater detail in applicant's co-pending related
applications entitled "Method and Apparatus for Object Tracking and
Detection" and "Method and Apparatus for Object Surveillance with a
Movable Camera" filed concurrently herewith and incorporated herein
by reference.
[0023] For a fixed motion video camera 108 (not shown) not having a
servo controlled pan-tilt-zoom assembly 110, the computer 102 uses
the video signal and the current magnification of the camera 108 to
create a control signal similar to the control signal of the
moveable camera 114. However, the control signal for a fixed camera
only uses a zoom function already on the camera 108 to capture the
object of interest in greater detail.
[0024] The video signal 112 received from video camera 108 is
passed out from the computer 102 as video signal out 106 either
directly to a display 104 or modified to include graphic
information that may be used to set up response parameters of a
tracking program, indicate an object that is actively being tracked
or identify (or allow identification of) user-defined zones for
tracking. A pointing device 116 may be a mouse or trackball and is
the user input for modifying said response parameters or defining
the tracking zones. The pointing device 116 may also be used by the
user to select an object that appears within the field of view 118
such that tracking program residing on the computer 102
acknowledges user's selection and initiates tracking of the
selected object.
[0025] FIG. 2 is an illustration of an exemplary field of view 200
for a camera highlighting user-defined zones according to the
present invention. In this illustration, the environment that the
motion video camera 108 is receiving within its field of view 200
is shown. For the purpose of illustration, the environment contains
a house 220, a tree 230, a walkway 240, and a pond 250. There are
five different types of zones 202, 204, 206, 208, and 210 that
control tracking behavior and subsequent video output. These zones
are defined as follows:
1 Zones Definition Application Tracking Zone Sets the overall
surveillance Include only the region region defining pan and tilt
in which tracking is limits of camera. The tracker required. does
not track nor does it move the camera beyond the tracking zone.
Black-out Zone Sets regions within the Reflections, high traffic
tracking zone in which areas, machinery, other tracker will not
track. The unwanted distractions. tracker does not track any target
that moves into a black-out zone, nor does it originate a target
within a blackout zone. Exclusion Zone Sets regions within the
Trees, machinery, water tracking zone in which tracker and other
stationary will not originate a new track reflective surfaces. but
that tracked objects may enter and exit. The tracker maintains a
track that enters an exclusion zone. Entry Zone Sets region within
the tracking Watch doors, windows, zone in which tracker will
vehicles and other automatically originate a new assets. track and
follow. When the tracker is programmed to search only the entry
zone, then this is the only region in which tracks can originate.
Privacy Zones Sets regions in the tracking Areas within tracker
zone not viewable by the field of view but operator. The tracker
requiring privacy from maintains tracking passing camera such as
office into and out of privacy zones. windows and homes.
[0026] The tracking zone 208 is shown on the display encompassing
the house 220, the tree 230, the walkway 240, and the pond 250.
Only for the purpose of illustration is the tracking zone 208
contained within a single field of view 118. For embodiments using
a moveable camera 108, the tracking zone 208 may span several
fields of view. An exclusion zone 250 is shown encompassing that
portion of the pond 250 that is within the tracking zone 208. A
black-out zone 202 is shown encompassing the leafy portion of the
tree 230 which may generate tracking events when the leaves move in
the wind. Since in this field of view 200, it is not anticipated
that tracks will not enter into the perimeter, the entire region
receives a black-out zone 202 rather than an exclusion zone 204. An
entry zone 206 is shown encompassing the door of the house 220. A
privacy zone 210 is shown encompassing the window of the house
220.
[0027] FIG. 3 is a zone defining processing system 120 for defining
surveillance zones in the camera's 108 field of view according to
an embodiment of the present invention. The zone defining
processing system 120 has a field of view (FOV) area definer 132
that connects interfaces to various devices (i.e. camera 108, input
device 116, and display 104), a zone type database 128 and a
tracking/monitoring controller 130. A camera interface 122 receives
the video signal in from the motion video camera 108 and passes
this signal to the FOV area definer 132. The FOV area definer 132
can pass this signal directly to a display interface 126 to be
shown on the display 106 or the signal may be modified to include a
graphic overlay containing information on zones within the field of
view.
[0028] The FOV area definer 132 may send a zone type selection menu
to the display interface 126 to prompt a user to select a zone type
using the input device 116. The zone type database 128 contains
definitions for the different types of zones as well as
corresponding actions for each zone type (i.e. do not initiate
tracking objects but continue following previous tracks).
Indication of a selected zone type is received at a input device
interface 124.
[0029] After a zone type has been selected the FOV area definer 132
provides the display interface 126 with a graphic overlay for the
field of view to assist the user in drawing a zone of the selected
type. After an indication of a drawn zone has been received through
the input device interface 124, the FOV area definer 132 provides
the display interface 126 with a graphic overlay indicating the
defined zone.
[0030] The tracking/monitoring controller 130 tracks and monitors
defined objects within the field of view. Given a field of view the
tracking/monitoring controller 130 consults the FOV area definer
132 to determine a mapping between defined zones and the field of
view. The FOV area definer 132 provides the tracking/monitoring
controller 130 with the mapping between defined zones and the field
of view as well as a definition of the zone types and the
corresponding actions for each zone type.
[0031] FIG. 4 is a flow chart illustrating a method 300 of
identifying user-defined zones according to the present invention.
All of these zones are shown on the display 104 as graphic overlays
to the video signal in 112 received from the camera 108 in step
302. An input device such as a mouse 116 is provided for selecting
a zone type in step 304. The type of zone may be selected, for
example, from a menu listing all zone types or applicable zone
types given other settings. These zones may be selected and resized
in step 306 by a user with a mouse 116 or similar pointing device
by holding down a mouse button and moving the mouse 116 to resize a
rectangular region over some portion of the display's image. If the
extent of a rectangular region exceeds a single field of view, the
mouse 116 is moved to any of the four edges or corners of the
display which results in the tracking program residing on the
computer 102 sending control signal 114 to the pan-tilt-zoom
assembly 110 resulting in an altered field of view. The mouse
button is released when the desired region is encompassed by a
rectangle. After the size of the zone has been drawn in step 306,
the method 300 is repeated for multiple instances of zones of a
single type, as applicable, as for other types of zones. Multiple
overlapping and non overlapping shapes may be used to define more
complex zones. Once these regions are defined, the tracker performs
in its environment according to the rules that are defined for each
type of region.
[0032] FIG. 5 is a flow chart illustrating a general method 400 for
video surveillance using the user-defined zones identified by the
method 300 in FIG. 4. The video surveillance system continuously
monitors a tracking zone (except for any black-out zones) in the
field of view for movement 402. When movement is detected 404
subsequent video frames are compared 406 to determine what zone the
movement occurred in 408. If the movement is not in a black-out
zone or exclusion zone the object is isolated 410 and tracking
starts 412. If the movement is in a black-out zone or exclusion
zone tracking is not initiated and the video surveillance system
continues to monitor the tracking zone for movement 402. While an
object is being tracked if it leaves the current field of view and
enters a new field of view 414 the camera 108 may be moved 418 to
center the tracked object in the camera's 108 field of view.
Movement of the camera 108 to maintain a moving object in the field
of view is discussed in more detail in applicant's co-pending
application related applications entitled "Method and Apparatus for
Object Surveillance with a Movable Camera" filed concurrently
herewith and incorporated herein by reference. If the object enters
a black-out zone or exits the tracking zone 416 then tracking stops
and the system continues to monitor the tracking zone for movement
402. If the object has not entered a black-out zone or exited the
tracking zone then the object continues to be tracked.
[0033] If movement is not detected in step 404 then the camera 108
is moved to the next field of view 403 to continue searching for
movement 402.
[0034] It is apparent to one skilled in the art that numerous
modifications and departures from the specific embodiments
described herein may be made without departing from the spirit and
scope of the invention.
* * * * *