Abstract:
A system and method for automated operation of a camera system is disclosed. A positioning system moves the camera system to a field of view to search for objects or events of interest to track. If objects or events of interest are detected prior to the expiration of a dwell timer, the dwell timer is interrupted and tracking of the objects or events of interest is initiated. To prevent the security camera from being distracted indefinitely by unimportant objects, the positioning system changes the field of view of the security system upon expiration of a track timer. Alternatively, if the security camera does not identify an object to track prior to expiration of a dwell timer, then the positioning system changes the field of view of the camera system to search for other objects or events of interest.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Security systems are often installed within residential, commercial, industrial, or governmental buildings. Some examples of these buildings include offices, hospitals, casinos, warehouses, academic institutions, or shopping malls. The security systems are generally comprised of security devices such as security camera systems (or camera systems), motion sensors, alarms, fingerprint scanners, and access control readers, to a list a few examples. 
         [0002]    Many of the security systems utilize motorized security camera systems to capture images, such as video content (or data), of scenes. One example of a motorized security camera system is a pan-tilt-zoom (or PTZ) camera system. Typically, PTZ camera systems are manually operated by an operator (e.g., security personnel) via a control mechanism, such as a joystick. 
         [0003]    One problem with manually operated security camera systems is that when the security camera systems are not in use, they are often left facing in a “wrong” direction when events of interest are occurring. Thus, the camera systems often fail to capture objects or events of interest. 
         [0004]    To alleviate the problem of potentially missing objects or events of interest, many security camera systems implement automated guard tours. A guard tour is comprised of a series of preset fields of view (camera or lens orientations) and zoom levels, which are referred to as set points. In operation, a positioning system of the security camera system automatically moves the camera system from one set point to another in a predefined order or at random. This movement from one set point to another changes the lens orientation of the camera system and thus also changes the field of view of the camera system. 
         [0005]    Even when an automated guard tour is running, the security camera systems may still miss events of interest. This is because the guard tour is often comprised of set points and the security camera systems may be positioned at a “wrong” set point when the event is occurring. Alternatively, the events of interest could occur in a field of view that is not covered by any of the set points of the camera systems. Additionally, if objects or events of interest are in motion, the objects or events may move out of the field of view of the security camera system. Yet another problem with the guard tours is that the set points include predefined zoom levels. Thus, the security camera systems may be zoomed out too far to capture details of the object or event. Similarly, the security camera systems may be zoomed in too far and miss events due to a narrow field of view of the set point. 
         [0006]    Recently, video content analysis tools have been developed for security camera systems to enable the security camera systems to automatically identify and track objects or events of interest. This feature may even be combined with guard touring. Once the motion is detected, the security camera systems suspend the guard tour and initiate tracking of the objects or events of interest. 
       SUMMARY OF THE INVENTION 
       [0007]    Security camera systems that implement automatic tracking still suffer from several problems. The first problem occurs when multiple objects or events of interest are detected (e.g., when the camera systems detect multiple cars moving in different directions at the same time). In this case, the camera systems must determine which of the objects to follow. Occasionally, the camera systems choose the wrong object to track. The second problem is that the security camera systems may become distracted by “uninteresting” objects or events (e.g., leaves blowing in the wind). These uninteresting objects or events cause the camera systems to indefinitely track uninteresting objects or events while interesting events are occurring elsewhere. 
         [0008]    The present system is directed to automated camera system operation that includes video analytics. More specifically, the system provides for security camera systems that implement intelligent guard tours, which enable the camera systems to automatically track events or objects of interest, but also prevent the security camera systems from being distracted indefinitely by unimportant objects or events. 
         [0009]    In more detail, the security camera systems search for objects or events of interest to track and dwell timers are initiated. If the dwell timer expires before objects of interest are detected, then the positioning system of the security camera move changes the field of view of the camera system to search for other objects or events of interest to track. Alternatively, if objects or events of interest are identified prior to the expiration of the dwell timer, the dwell timers are interrupted and automatic tracking of the objects or events of interest is initiated. To prevent the security camera system from being distracted indefinitely by unimportant objects, the lens system is moved to a different position (i.e., set point) after a predefined period of time (e.g., the expiration of a track timer). 
         [0010]    In general, according to one aspect, the invention features a method of automated operation of a motorized camera system. The method includes tracking objects of interest by controlling a positioning system of the camera system. Additionally, the method includes suspending tracking of the objects and controlling the positioning system to change the field of view of the camera system and then searching for new objects of interest to track when the objects have been tracked for a time. 
         [0011]    In embodiments, the method further comprises starting a track timer in response to detecting new objects of interest to track, tracking the new objects by controlling the positioning system, and controlling the positioning system to change the field of view of the camera system to search for new objects of interest to track upon the expiration of the track timer. 
         [0012]    Generally, the next field of view of the camera system is determined by retrieving a set point from a series of stored set points. Alternatively, the next field of view of the camera system is based on a current field of view of the camera system after suspending tracking a current object. 
         [0013]    Typically, if objects of interest are not identified prior to expiration of a dwell timer, the positioning system changes the field of view of the camera system to search for new objects of interest. Alternatively, if new objects of interest are identified, the new objects of interest are tracked by controlling the positioning system of the camera system. 
         [0014]    Preferably, the tracking the objects of interest further includes controlling the positioning system and a zoom actuator of the lens system to ensure that the objects of interest are zoomed and centered in the field of view of the camera system. 
         [0015]    In a typical implementation, objects of interest are prioritized when multiple objects of interest are identified and then tracking is initiated for the object of interest with the highest priority. 
         [0016]    In embodiments, searching for the objects of interest includes detecting objects of interest based on motion, biometric information, and/or license plate information of vehicles, to list a few examples. 
         [0017]    Generally, the camera system is programmed with a series of set points that correspond to different fields of view of the camera system. 
         [0018]    In general, according to another aspect, the invention features a security camera system, which includes a positioning system that moves a field of view of the camera system. Additionally, the system includes a lens system and imaging sensor that generate images of the field of view of the camera system. 
         [0019]    The system further includes a video analysis system that identifies objects of interest within the images, tracks the objects for a time, and then suspends the tracking to search for new objects of interest to track after the positioning system changes the field of view of the camera system. 
         [0020]    In one embodiment, the video analysis system is implemented internally on the security camera system. In an alternative embodiment, the video analysis system is implemented on an external system that accesses images stored possibly to a network video recorder system. 
         [0021]    The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings: 
           [0023]      FIG. 1A  is a schematic diagram of a security system, which includes motorized security camera systems installed on a network. 
           [0024]      FIG. 1B  is a block diagram illustrating a camera system. 
           [0025]      FIG. 1C  is a block diagram illustrating an alternative embodiment of the camera system, which includes an external camera positioning system. 
           [0026]      FIG. 2  is a block diagram illustrating an alternative embodiment of the security system in which the video analysis system is external to the security camera system. 
           [0027]      FIG. 3  is a flowchart illustrating the steps performed by the security camera systems to identify and track objects of interest. 
           [0028]      FIG. 4  illustrates an example security camera systems installed on the exterior of a building to monitor areas around the building. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
         [0030]    As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Further, the singular forms including the articles “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms: includes, comprises, including and/or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Further, it will be understood that when an element, including component or subsystem, is referred to and/or shown as being connected or coupled to another element, it can be directly connected or coupled to the other element or intervening elements may be present. 
         [0031]      FIG. 1A  is a block diagram of a security system  100 , which includes security camera systems (camera systems)  104 - 1  to  104 - n  installed on a network  106 . 
         [0032]    In the illustrated embodiment, the security system  100  is installed within or around a building  50 , such as an office, hospital, casino, warehouse, academic institution, or shopping mall, to list a few examples. 
         [0033]    The camera systems  104 - 1  to  104 - n  capture a series of images as video data. Alternatively, the camera systems  104 - 1  to  104 - n  may capture a series images at predefined intervals (e.g., once every 30 seconds). In a preferred embodiment, the camera systems  104 - 1  to  104 - n  use motorized or scanning positioning system such as pan-tilt or pan-tilt-zoom (PTZ) systems. 
         [0034]    In a typical implementation, the camera systems  104 - 1  to  104 - n  or the controller  108  store set points, which are preset positions of the lens or the camera defined as the triple of a pan angle, a tilt angle, and a zoom level that correspond to different fields of view. In the illustrated example, these set points are shown as arrows  105 - 1  to  105 - n.    
         [0035]    While not illustrated, the security system  100  typically includes additional security devices such as motion sensors, alarms/sirens, fingerprint scanners, door controllers, and access control system, (e.g., readers), to a list a few examples. 
         [0036]    In a typical implementation, the camera systems  104 - 1  to  104 - n  are moved from one set point to another in a predefined order. Alternatively, the camera systems may be repositioned at random. This movement from one set point to the next enables the camera systems to capture video data (e.g., a series of images) in different fields of view. In general, the repositioning of the security camera system to the different set points is often referred to as a guard tour, which is executed automatically by the camera systems  104 - 1  to  104 - n  after a period if inactivity or when the operator is not manually controller or steering the camera systems. In an alternative embodiment, the guard tour is an operation mode that is selected by an operator (e.g., security personnel)  118 . 
         [0037]    In the preferred embodiment, the security camera systems  104 - 1  to  104 - n  identify and track objects of interest. In the illustrated example, people  102 - 1  to  102 - n  are examples of objects of interest. Other objects of interest include vehicles or unattended items (e.g., boxes or luggage) for example. Additionally, the dog  103  represents a possible distraction (or “uninteresting” object). 
         [0038]    In the illustrated embodiment, the camera systems  104 - 1  to  104 - n  are connected to the network  106 , which is typically a public and/or private data network. The network may also include an enterprise network, university network, government network, and/or mobile broadband data network, to list a few examples. In some embodiments, the security network  106  includes wireless portions. 
         [0039]    The system controller  108 , which is potentially housed in a control room  52  or other secure location, monitors and controls the camera systems  104 - 1  to  104 - n  via the security network  106 . Additionally, the images, such as video data captured by the security camera systems  104 - 1  to  104 - n  are sent to the system controller  108 . The system controller  108  forwards the received video data to a network video recorder (NVR)  110  for storage. The network video recorder (NVR)  110  typically adds time and date information in addition to other meta data to allow the video data to be indexed and reviewed at a later date. 
         [0040]    Additionally, the control room or other monitoring location  52  also includes one or more workstations  114 , which are operated by one or more operators (e.g., security personnel)  118 . In the illustrated example, the workstations  114  include input devices (e.g., joysticks) that enable the operators  118  to manually control the field of view including zoom of the security camera systems  104 - 01  to  104 - n.    
         [0041]      FIG. 1B  is a block diagram illustrating a camera system  104  according to the present invention. 
         [0042]    In the illustrated embodiment, the camera system  104  includes a camera controller  152 , which controls an integrated or separate memory  154  and a network interface controller  150 . 
         [0043]    The security camera system  104  includes an adjustable lens system  170 , which typically has one or more optical elements, such as lenses, for zooming and a focusing the camera system. In the illustrated example, the lens system  170  includes a zoom actuator  155  that controls the level of zoom of the lens system  170 . 
         [0044]    The lens system  170  of the security camera system  104  may include different optics depending on the installation location. For example, the lens system  170  may utilize a wide angle lens, a fisheye lens, or telephoto lens, to list a few examples. 
         [0045]    In still other examples, the zoom capability is not provided or a digital zoom is used. 
         [0046]    The lens system  170  captures light and directs the captured light to an imaging sensor  168 , which converts the captured light into a series of electronic images that form video data. Generally, the imaging sensor  168  is a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) device. The imaging sensor  168  is directly behind the lens system  170  in order to receive the light captured by the lens system  170 . 
         [0047]    The security camera system  104  further includes a lens positioning system (positioning system)  156 , such as a motorized gimbal. In the illustrated example, this positioning system  156  controls the direction and orientation of the lens system  170 . The positioning system  156  receives positioning commands from the camera controller  152  and moves the lens system  170  in order to change the field of view of the camera system in response to those received commands. The lens positioning system  156  is typically comprised one or more motors, which adjust a lens orientation (e.g., pan and tilt) of the security camera system  104  and move the lens system  170  to receive light from different fields of view. 
         [0048]    The image information captured by the imaging sensor  168  is sent to the camera video analysis system  158 . In some examples, this analysis is implemented on a separate video or digital signal processor. In other examples, it is implemented on the camera controller  152 . 
         [0049]    In the illustrated example, the camera video analysis system  158  includes a content analyzer  160 , object tracker  162 , dwell timer  164 , and track timer  166 . Typically, these components are processes executing on a processor or functionality provided by one or more processes executing on the processor. Additionally, the camera video analysis system  158  also stores or accesses a series of set points  165 . 
         [0050]    The content analyzer  160  utilizes video or image content analysis to detect and track objects or detect events of interest. Some examples of these video content analysis techniques include object identification, motion detection, biometric detection (e.g., human detection or face detection), vehicle detection, and license plate detection. 
         [0051]    The object tracker  162  tracks the objects or events of interest and sends positioning commands for the lens positioning system  156 . The positioning commands keep the object or event of interest centered in the field of view and fully zoomed, in one implementation. 
         [0052]    The dwell timer  164  is a predefined or programmable length of time that the security camera system will remain at a set point (without identifying objects or events of interest) before the security camera system  104  moves to a different set point in the course of performing a guard tour. Similarly, the track timer  166  is a predefined length of time that the security camera system will track an object or event of interest before the positioning system of the security camera system  104  breaks off the tracking of the object and potentially moves to a different set point or position. 
         [0053]    The stored set points  165  are preset camera positions that are programmed into the security camera systems  104 - 1  to  104 - n.  These set points define fields of view, which are based on the lens orientations, and zoom levels of the camera systems  104 - 1  to  104 - n.  In the preferred embodiment, each set point is the triple of a pan angle, a tilt angle, and a zoom level. Often the set points are defined at the time of installation and will typically define fields of view within the camera system&#39;s range of movement that are associated potential areas of activity such as doorways, desks, or hallways, for example. 
         [0054]    The memory  154  is typically a non-volatile data storage element. In general, the memory  154  stores software code executed by the camera controller  152  and/or video analysis system  158  (e.g., software to control the lens position system  156  and drivers for the network interface controller  150 ). Additionally, the memory  154  may also buffer and/or store captured video data and/or the set points. 
         [0055]    The network interface controller (NIC)  150  enables the security camera system  104  to communicate over the network  106  and allows the image data be transmitted to the system controller  108 , the workstation  114 , and/or the network video recorder (NVR)  110 . Additionally, the network interface controller  150  allows for information or instructions to be received from the system controller  108  or workstation  114 , for example. 
         [0056]    While not illustrated, the camera systems may include additional components (or features). For example, the security camera systems may include a microphone and amplifier circuit to capture, filter, or enhance captured audio. Additionally, the camera system may further include infrared illumination to allow the camera systems operate in darkness or low-light conditions (i.e., “night vision”). 
         [0057]      FIG. 1C  is a block diagram illustrating an alternative embodiment of the camera system  104 , which is comprised of a security camera  107  and an external camera positioning system  159 . 
         [0058]    In general, the illustrated embodiment is nearly identical  FIG. 1B . However, in this embodiment, the positioning system is an external camera positioning system  157 . That is, the positioning system  157  is external to the security camera  107  and controls the pan and tilt of the camera  107  from the exterior of the security camera  107 . 
         [0059]    In one embodiment, the external camera positioning system  157  is a motorized gimbal system. In another embodiment, the external camera positioning system  157  is a rail system, which moves the camera system  104  along one or more rails to keep objects of interest in the field of view. In yet another embodiment, the external camera positioning system  157  is a cable system from which the camera is suspended. This system typically has two or more wires to move the camera over different areas. 
         [0060]    Typically, the external camera positioning system  157  is secured to a mounting point  159 , which enables the camera system to be installed on poles, walls, or ceilings for example. 
         [0061]      FIG. 2  is a block diagram illustrating an alternative embodiment of the security system  100  in which the video analysis system  112  is external to the security camera systems  104 - 1  to  104 - n.    
         [0062]    The embodiment illustrated is nearly identical to the embodiment illustrated with respect to  FIG. 1A . In this embodiment, however, video analysis is performed by an external video analysis system  112 , which analyzes the video data in real time as the video data are received from the camera systems and/or stored to the network video recorder  110 . In this example, the video analysis system analyzes the image information from one or more camera systems simultaneously and then sends back positioning and tracking commands. 
         [0063]      FIG. 3  is a flowchart illustrating the steps performed by the security camera systems  104 - 1  to  104 -and to identify and track objects of interest. 
         [0064]    In the first step  304 , the positioning system (e.g., reference numeral  156  or  157 ) and zoom actuator  155  move the camera system to the position of a first or initial set point (e.g., field of view), which is often defined by a pan angle, tilt angle, and zoom level. Next, the dwell timer  164  is started in step  306 . This dwell timer defines the length of time that the security camera system remains at the set point before moving to a different set point. Then, the video content analysis is started for the set point in step  308  and the video analysis system (e.g., camera video analysis system  158  or the external video analysis system  112 ) performs analysis of the captured video content in step  310 . 
         [0065]    If the dwell timer  164  has expired (step  312 ), then the video analysis system stops the analysis of the video data in step  314 . In the next step  315 , the positioning system and zoom actuator  155  move the camera system to the next set point. Alternatively, if the dwell timer  164  has not expired, then the video analysis system determines whether objects or events of interests have been detected in step  316 . 
         [0066]    If objects or events of interest have not been detected, then the video analysis system continues to analyze the video data captured by the security camera system  104  at the current set point in step  310 . If, however, objects or events of interest are detected, then the video analysis system prioritizes the detected objects or events in step  317 . Additionally, the dwell timer is stopped in step  318 . Next, the video analysis system suspends the video data analysis for objects unrelated to the objects or events of interest in step  320 . In the next step  322 , a track timer  166  is started. In general, this track timer  166  defines the length of time that the security camera systems  104 - 1  to  104 - n  track an object or event of interest before breaking off the tracking of the object and moving to a different set point or new position. 
         [0067]    In the next step  324 , the object tracker  162  initiates tracking of the objects or events of interest. In step  326 , positioning commands are generated, which are then sent to the positioning system and the zoom actuator  155 . These positioning commands enable the camera system  104  to follow the objects or events of interest and maintain those object or events within the field of view of the camera system. In a preferred embodiment, the positioning commands are used to keep the objects or events of interest zoomed and centered in a field of view of the security camera system in step  327 . 
         [0068]    If the track timer  166  has not expired (in step  328 ), then the video analysis system continues to track the objects or events of interest. Conversely, if the track timer has expired, then tracking is stopped in step  330 . The positioning system and zoom actuator  155  then move the camera system  104  to the next set point. 
         [0069]      FIG. 4  illustrates an example of security camera systems  104 - 2 ,  104 - 3  installed on the exterior of a building  50  to monitor areas around the building  50 . 
         [0070]    In the illustrated example, the security camera systems  104 - 2 ,  104 - 3  monitor a parking lot  200  and an entrance area of the building  50 . While only two camera systems are illustrated in the example, a typical security system may include additional camera systems and/or security devices (e.g., motion detectors, microphones) located around the perimeter of the building  50 . Additionally, security systems often include multiple camera systems installed at the same location. This allows the security system  100  to simultaneously track multiple objects or events of interest from the same vantage point. Alternatively, one or cameras may be used to track objects or events of interest while the other cameras continue operating in guard tour mode. 
         [0071]    Each of the camera systems  104 - 2 ,  104 - 3  stores a series of set points, which are illustrated as the dotted arrows  105 - 5  to  105 - 8  and  105 - 9  to  105 - 12 . In operation, the positioning systems of the camera systems  104 - 2 ,  104 - 3  will move the camera systems from one set point to the next to search for objects or events of interest to track. 
         [0072]    Within the parking lot  200  are “uninteresting” objects (e.g., parked cars  204 - 1  to  204 - n ). Conversely, a group of people  202  moving towards the entrance of the building  50  and moving cars  208 ,  206  are objects of interest. 
         [0073]    In a typical implementation, the objects or events of interest are prioritized. For example, the group of the people  202  might be assigned the highest priority because they are moving towards the entrance of the building and are the closest objects to the building. 
         [0074]    In some embodiments, the system controller  108  provides instructions to each security camera system to indicate which objects or events of interest should be tracked by the camera systems. This prevents multiple camera systems from focusing on the same object or event of interest while other objects or events of interest remained untracked. Illustrated by way of example, the car  208  would likely be identified by both of the security camera systems  104 - 2 ,  104 - 3 . As a result, both camera systems might initiate tracking this object of interest. To prevent both of these camera systems from tracking the same event of interest (and ignoring, for example, the group of people), the system controller  108  (or possibly an operator  118 ) assigns objects of interest to each of security camera systems. 
         [0075]    According to the invention, when the camera systems  104 - 2 ,  104 - 3  are operating in an automated fashion, they will automatically track objects of interest by controlling the positioning system of the camera system to change the fields of view. For example, camera system  104 - 3  may track the group of people  202  as they move toward the building  50 . 
         [0076]    This group  202  will only be tracked for a set time period defined by the track timer. After expiration of that time period, camera system  104 - 3  will suspend tracking of the group  202  and change the field of view (e.g., by moving the lens system or the camera itself) of the camera system to a different position such as the position associated with set point  105 - 6 . In one embodiment, the next set point is the set point in the series of stored set points. In another embodiment the next set point is determined by comparing the different set points to the camera system&#39;s current field of view and choosing a set point that corresponds to a most diametrically opposed field of view to the current set point. 
         [0077]    At the new position associated with, for example, set point  105 - 6 , the camera system begins searching for new objects to track such as car  204 - 2 . In this way, the camera system does not become fixated with only one object of interest (e.g., the group  202 ), but continues to search for new objects to track and perform the guard tour. 
         [0078]    While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.