US20120194357A1 - Traffic violation detection, recording, and evidence processing systems and methods - Google Patents

Abstract

Systems and methods are disclosed for detecting and recording an event, e.g., a traffic accident, using a sound monitor configured to capture ambient sound of a region under surveillance. The ambient sound is processed and compared with a pre-determined sound profile indicative of the event. At least one camera is configured to capture images of the region and a storage means temporarily stores the images. An identifying means identifies stored images associated with the event so that the stored images can be processed to provide evidence of the event. Events may be communicated in real-time between violation detection and recording systems and a server. A database stores information related to the events, and the database may be accessed interactively according to different access preferences of different categories of authorized users and according to a user's level of access and defined functionality.

Description

RELATED APPLICATIONS
• This application is a divisional of U.S. patent application Ser. No. 12/689,294, filed Jan. 19, 2010, which is both a divisional of U.S. patent application Ser. No. 10/555,634, filed Mar. 17, 2006 and a continuation-in-part of U.S. patent application Ser. No. 10/430,032, filed May 5, 2003. U.S. patent application Ser. No. 10/555,634 is both a National Stage Entry of International Application No. PCT/AU2004/000572, filed May 3, 2004 and a continuation-in-part of the aforementioned U.S. patent application Ser. No. 10/430,032. International Application No. PCT/AU2004/000572 also claims the benefit of the aforementioned U.S. patent application Ser. No. 10/430,032. Each aforementioned patent application is hereby incorporated by reference herein in its entirety.
TECHNICAL FIELD
• This disclosure relates to a violation detection and recording system for traffic violations such as red light traffic violations or speed violations, and to a violation evidence management and processing system.
BACKGROUND INFORMATION
• Traffic camera law enforcement has traditionally used 35 mm film-based cameras for the detection of speed and red-light violations.
• In the case of red light violations, the camera is used in conjunction with vehicle detection systems that are usually in-ground (in-road) sensors, e.g., inductive loops, which detect the presence of a vehicle at a particular point on the roadway. The camera system is also connected to the traffic signal controller, generally the red feed for the purpose of co-coordinating to the red signal phase. In principle an image of an offending vehicle is taken when a vehicle is detected about to enter the intersection, and/or in the intersection during the red signal phase. A common practice is to take two images of a vehicle as it progresses through the intersection in order to provide sufficient evidence for a prosecution.
• With speed violations, similar film-based cameras are used with a speed-measuring device—either in-ground loops for fixed-speed traps, or radar commonly used by mobile speed enforcement units. For speed enforcement, a picture of the vehicle is captured when the speed measuring system detects a vehicle traveling at a speed in excess of a preset threshold speed.
• The film-camera systems have required white light illumination generally in the form of flash units, to provide sufficient light to capture violation images in poor ambient light or at night.
• With the advent of digital imaging traffic cameras the film-based cameras are being replaced by digital cameras however the violation detection and recording and illumination systems have remained fundamentally as for film-based operations.
• Similarly while the advent of digital cameras is removing the need to digitize film images to allow automated processing and allows the option of centralized processing, processing software still has to be installed and maintained locally in each processing or user location. Additionally, users other than authorized processing officers must typically request issue of violation information according to standard formats or reports and are barred from interactivity with system data.
• Some fundamental disadvantages of these commonly applied systems are as follows:
• (a) The detection system is invariably unable to provide a trigger point that is sufficiently consistent to ensure that the positioning of vehicles at the time of imaging is identical. To compensate for this a wider angle lens is used with the consequence of reducing the available resolution for effective and efficient license plate recognition during subsequent evidence processing.
• (b) Conventional systems typically capture a single image of the vehicle license plate. If this image is obscured or poorly focused, it may be impossible to identify the vehicle. Likewise, with only one image of the driver, it may be difficult or impossible to provide an identifiable driver image where this is required.
• (c) High construction and maintenance costs (i.e., because of the costs of installing and maintaining in-ground sensors, underground cabling and connections to traffic signal controllers, flash units and in some instances where digital cameras are used, communications lines).
• (d) The use of flash illumination may be detrimental at night to oncoming traffic and has the potential to cause temporary driver blindness and consequent safety risks as well as preventing authorities from deploying systems covertly.
• (e) The requirement to install flash illumination units (often on a separate pole) also incurs additional supply, installation, maintenance and running costs and creates additional visual pollution.
• (f) Where digital cameras are used, systems either require the availability of high-speed communications lines to meet the demands of communicating high-resolution images, or else images and data must be collected manually.
• (g) Purpose built, high-resolution, digital traffic cameras are relatively expensive, adding to costs of traffic program installations and operation.
• (h) Traffic violation evidence collected by conventional systems includes time and data information provided by the camera computer clock which can be subject to error and therefore can prejudice the validity of evidence.
• (i) The requirement that violation processing software be installed and maintained in all computers in all processing offices and on all client computer systems in the various client locations incurs high program implementation and support costs.
• (j) With the exception of authorized processing personnel, users of violation evidence such as courts or police departments have been denied interactive access to information held by the central processing system and have only been able to request and view standard reports prepared for them by the relevant processing office.
• Furthermore, traffic violation systems often use cameras which are housed in dome enclosures. Using low-cost digital video cameras as capture devices places inherent limitations on the resolution of the video-footage. To counter this, a high powered lens is typically utilized. However, the size and weight of high powered lenses makes them impractical for dome enclosures, because much of the space in the enclosure needs to be taken up by a motor and moving mechanism for moving the camera. Thus, a reduced amount of room is provided for the lens. Furthermore, the size of the camera and lens is limited by the power of the motor controlling its movement.
SUMMARY
• A first aspect of embodiments described herein may be said to reside in a traffic violation or event detection, recording, and processing system, including at least one camera for monitoring a region under surveillance; means for supplying independently sourced and verifiable time, date, and location data to provide an indication of the time, date, and location of a violation; a storing means for storing continuous images taken by the at least one camera; a non-intrusive violation detection means for detecting vehicle presence and movement through the region and for providing an indication of a violation; and processing means for identifying images stored in the storage means and which relate to a violation detected by the violation detection means so that images associated with a violation are identifiable and can be processed to provide evidence of the violation and also identify the vehicle associated with the violation.
• This aspect of the embodiments may also be said to be implemented in a method of detecting a traffic violation, including the steps of monitoring a region of a roadway with at least one camera; monitoring vehicle presence and movement through the region using a non-intrusive vehicle detection means; storing images taken by the at least one camera; detecting a traffic violation in the region under surveillance; determining images stored by the storage means which relate to the traffic violation so that images can be used as evidence of the violation and also to identify the vehicle associated with the violation; and stamping the images with time, date, and location data which is independently sourced to provide the time, date, and location of the violation.
• According to another aspect of the embodiments, the cameras continuously take images of the region under surveillance instead of triggering camera imaging of vehicles in that region. Images captured by the at least one camera can be used to show the violation and to identify the vehicle associated with the violation. Since the violation detection means detects when a violation occurs, and the continuous captured images which relate to that violation are determined, lo-lux, relatively inexpensive cameras can be used that do not include flash illumination.
• Thus, the system and method of this aspect of the embodiments do away with the need to provide an intrusive vehicle presence detection system such as inductive loops or other physical sensors and more importantly, the detection system need not provide a trigger point because the region under surveillance is continuously monitored by the cameras and images are continuously stored.
• In one embodiment, the traffic event being detected recorded and processed is a red light violation.
• In one embodiment, the system includes at least one wide angle camera and at least one narrow angle camera. The wide angle camera can provide an image of the area under surveillance, and the narrow angle camera can provide an image which enables a vehicle involved in the violation to be identified.
• In this embodiment the violation detection means comprises image processing means for processing images captured by the said wide angle camera or at least one narrow angle camera to identify changes in the color of the traffic signals to thereby make a determination of the commencement and end of a red light traffic phase and therefore define a violation period. If the violation detection means determines that a vehicle is in the region under surveillance during that period, a set of multiple images stored in the storage means for that period is identified and then processed to provide evidence of the violation event. Another set of multiple images captured by a narrow angle camera during that period is identified and then processed also to identify the vehicle associated with the violation. Optionally, e.g., if required under law, a further set of multiple images captured by an additional narrow angle camera during that period is identified and then processed to identify the driver of the vehicle associated with the violation.
• In this embodiment, a vehicle in the region under surveillance during the red light phase period is determined by the processing means processing images captured by one of the cameras so that by comparing images a change in image can identify a vehicle passing through the region during the red light phase. Thus, in one embodiment, the wide angle camera which captures images of the region under surveillance can also capture images of the traffic signals to enable the red light phase of the signals to be identified. However, in other embodiments separate cameras could be used for capturing images of the region under surveillance and the traffic lights so that one camera is dedicated only to capturing images of the traffic lights and not the region under surveillance.
• The cameras may be off the shelf digital or video cameras with an ability to take images in very low (or close to zero lux) lighting conditions and have an auto iris to adjust for such differing lighting conditions. Such cameras are readily available and made by numerous well known manufactures including Sony, Kodak, Canon, Philips, and others.
• The cameras have a pixel resolution of 768×576 and a sustainable imaging rate of at least twenty five frames per second, according to one embodiment.
• The storage means may include temporary memory buffers for temporarily continuously storing images taken by the wide angle camera and at least one narrow angle camera, and a secondary storage means for storing images associated with a violation so that the images stored in the secondary storage means can be communicated for subsequent processing to provide the evidence of the violation and also the vehicle associated with the violation. All images recorded by the cameras are stamped with GPS-sourced location, date, time information, and other relevant violation data, according to one embodiment.
• In some embodiments, the images stored in the temporary storage means can be deleted, or overwritten, after a predetermined period.
• In some embodiments, the wide angle camera continuously captures images of the traffic signal so that the red traffic signal can be identified to make the determination of the commencement and end of the red light traffic phase.
• In one embodiment, the non-intrusive vehicle detection device that monitors vehicle presence in and movement through the intersection utilizes a camera, mounted perpendicular to the roadway, to continuously capture images of all traffic lanes and apply computer imaging software to analyze these images to track and identify vehicle movement in the region under surveillance.
• In another embodiment, the non-intrusive violation detection means comprises apparatus for determining when a red light phase of a traffic signal is present, and a device for determining when a vehicle has violated the red light phase of the traffic signal whilst the red light phase of the traffic signal is active. In some embodiments, the apparatus may comprise the said processing means for processing an image of the traffic signal to identify when the red light phase of the traffic signal is present. However, in other embodiments, the apparatus comprises an inductive sensor for determining when current is supplied to the traffic signal to thereby provide an indication that the red light phase is active.
• In another embodiment, the device for determining when the vehicle has violated the red light signal comprises a camera mounted perpendicular to the direction of traffic flow for determining when a vehicle crosses a predetermined line whilst the red light phase is active, thereby indicating that the vehicle has committed a violation of the red light phase of the traffic signal. In another embodiment the device may comprise at least one ranging laser for detecting a vehicle.
• In one embodiment, a plurality of narrow angled cameras are utilized for monitoring respective parts of the region so that all parts of the region are monitored by the plurality of narrow angled cameras. In some embodiments, each narrow angled camera monitors a lane of the roadway. In another embodiment, the narrow angled cameras are used to provide a series of images of the vehicle so that the number plate of the vehicle can be identified to thereby identify the vehicle associated with the violation.
• An enhancement of this red light violation detection and recording system may provide an intersection accident monitoring means to monitor and record images of traffic accidents within the region under surveillance during any traffic signal phase.
• In this enhancement, an accident monitoring means is incorporated to monitor and record the ambient sound within the region under surveillance.
• The accident monitoring means may comprise a sound monitoring device or microphone that analyzes sound recordings to detect noise signatures of a traffic accident. When such a noise signature is detected, a set of multiple images taken by the wide angle camera and stored in the storage means for that period is identified to provide a visual record of the traffic accident.
• In another embodiment, the traffic event being detected recorded and processed is a speed violation.
• In this embodiment the violation detection means comprises vehicle speed determining means for determining the speed of a vehicle in the region under surveillance.
• The speed determination means may comprise a non-intrusive Doppler radar system or a laser device.
• In this embodiment when a vehicle is detected exceeding a preset speed threshold by the violation detection means a set of multiple images stored in the storage means and associated with the violation is identified and processed to provide evidence of the violation and also to identify the vehicle associated with the violation.
• The temporary storage means may comprise temporary memory buffers.
• The cameras may be off the shelf digital or video cameras with an ability to take images in very low (or close to zero lux) lighting conditions and have an auto iris to adjust for such differing lighting conditions. Such cameras are readily available and made by numerous well known manufactures including Sony, Kodak, Canon, Philips and others.
• The cameras may have a pixel resolution of 768×576 and a sustainable imaging rate of at least twenty five frames per second.
• The embodiment may also be said reside in a traffic violation detection, recording and evidence processing system, including at least one camera for monitoring a region under surveillance and for viewing a traffic signal which includes traffic lights which change, to control flow of traffic through the region; temporary storage means for continuously storing images taken by the at least one camera; processing means for processing images taken by the at least one camera to determine changes in traffic lights of the traffic signal to determine the commencement and end of a traffic phase of the traffic signal to define a violation period; and processing means for determining that a violation has occurred from the images captured by the at least one camera and for identifying those images in the temporary storage means which are associated with the violation so that those images associated with the violation can be processed to provide evidence of the violation and to identify the vehicle associated with the violation.
• The processing means may include secondary storage means for storing the images originally stored in the temporary storage means and which are associated with the violation.
• The system may include a communication link for communicating images stored in the secondary storage device to a central facility for processing to provide evidence of the violation and identify the vehicle associated with the violation and the driver if required in some jurisdictions.
• In one embodiment at least one camera comprises a wide angle camera which captures an image of the region under surveillance and also of the traffic signal, and a plurality of narrow angle cameras for monitoring different parts of the region under surveillance.
• The secondary storage device may comprise a hard disk of the processing means.
• The communication link may be a wireless and/or Internet enabled communication link for transmission of data including the images relating to a violation from the processing means to a central facility.
• Another aspect of the embodiments may also be said to be implemented in a method of detecting a traffic violation including the steps of detecting a region of a roadway and a traffic signal by at least one camera; continuously capturing images of the region and signal and temporarily storing those images; detecting from the images changes in the traffic signal so that the commencement and end of a particular light traffic phase can be determined to define a violation period; and detecting a traffic violation in the violation period and identifying the stored images associated with the violation so that the stored images can be processed to provide evidence of the violation and identify the vehicle associated with the violation.
• In another embodiment, the traffic event being detected, recorded, and processed is a traffic accident occurring in an intersection.
• In this embodiment the event detection means comprises sound monitoring means for determining the sound level of a vehicle in the region under surveillance.
• The sound monitoring means comprises a microphone and ambient sound measuring device.
• In this embodiment when the sound monitoring means detects a vehicle exceeding a preset noise threshold a set of multiple images recorded by the wide angle camera and corresponding sound recordings associated with the violation are stored in the storage means and are identified and processed to provide a visual record of the accident.
• The temporary storage means may comprise temporary memory buffers.
• The cameras may be off the shelf digital or video cameras with an ability to take images in very low (or close to zero lux) lighting conditions and have an auto iris to adjust for such differing lighting conditions.
• Such cameras are readily available and made by numerous well known manufactures including Sony, Kodak, Canon, Philips and others.
• The cameras may have a pixel resolution of 768×576 and a sustainable imaging rate of at least twenty five frames per second.
• Another aspect of the embodiments may also be said to be implemented in a traffic event detection recording and processing system, including at least one wide angle camera for monitoring a region under surveillance; a sound monitoring means to monitor and record ambient sound in the region under surveillance; temporary storage means for continuously storing images taken by the at least one camera and corresponding sound recordings; and processing means for determining that an intersection accident has occurred by analyzing the sound recordings obtained by the sound monitoring means and identifying those sound recordings and images which are associated with the accident event to provide a visual record of the event.
• The temporary storage means may comprise temporary memory buffers.
• The processing means may include secondary storage means for storing the images and corresponding sound recordings originally stored in the temporary storage means and which are associated with the event.
• At least one wide angle camera continuously monitors the region under surveillance, according to one embodiment
• The sound monitoring means may comprise at least one microphone or sound recording device that records the ambient sound of the region under surveillance.
• The processing means may include secondary storage means for storing the images and corresponding sound recordings originally stored in the temporary storage means and which are associated with the event.
• The secondary storage device may comprise a hard disk of the processing means.
• The communication link may be a wireless and/or Internet enabled communication link for transmission of data including the images relating to the event from the processing means to a central facility.
• An embodiment still further provides a method of storing and managing evidence of traffic violations and events which are detected and recorded by a plurality of violation detection and recording systems comprising the steps of continuously communicating evidence of traffic violations and events to at least one server; providing real-time communications between all violation detection and recording systems and the server(s); providing a database containing information relating to violations detected by the violation detection and recording systems; dividing the database according to the different access preferences of different categories of authorized users with each user's level of access and functionality being automatically defined by their unique password and log-in process; allowing browser-based access to information held in the database or databases at a pre-defined level of authority for any authorized user using a computer with Internet connectivity; allowing interactive access to and operation of the violation processing system for individual users to perform evidence management tasks specified by the authorities operating the system.
• The embodiment also provides a method of detecting and recording an event comprising the steps of continuously capturing and analyzing ambient sound of a region under surveillance to detect a defined event; monitoring the region by at least one camera; continuously capturing images of the region and temporarily storing those images; and detecting a violation from the captured sound and identifying the stored images associated with the event so that the stored images can be processed to provide evidence of the event.
• In a another embodiment, a violation processing solution utilizes Internet connectivity to provide a central database that allows interactive access accessed by authorized users in any location.
• A further aspect of the embodiments is concerned with providing a traffic violation system and camera which is more suitable for dome enclosures.
• The embodiment in a further aspect therefore provides a traffic violation detecting system, comprising a fixed camera for monitoring a plurality of lanes of a road and providing images of vehicles travelling in the lanes; a violation detecting system for detecting a traffic violation in any one of said plurality of lanes; and a reflecting system for selectively directing illumination from said any one of said plurality of lanes to said camera so that when a violation occurs in any one of said lanes, the reflecting system directs illumination from that lane to the camera so the camera can capture images of the violation occurring in that lane.
• Thus, according to this aspect of certain embodiments, a single camera can be used to provide images from a number of lanes without the need to move the camera. A fixed camera can be used because the reflecting system will reflect illumination from the lane in which a violation occurs to the camera. Thus, a motor need not be provided to move the camera and therefore the size of the camera is not limited by the power of a motor needed to control its movement. Because the camera need not be moved, if a mechanism is used to move the reflecting system, the mechanism may be smaller than other mechanisms typically used to move the camera. Thus, less space is taken up in a dome enclosure. A low cost camera can therefore be used and also a high powered lens provided to overcome inherent limitations on the resolution of the images captured by the camera. Thus, the need for a larger motor or a bulkier dome is avoided.
• The reflecting system may comprise a mirror and an adjusting mechanism for moving the mirror so the mirror reflects illumination from the said any one of the lanes to the camera.
• In another embodiment, the violation detecting system provide information relating to the lane in which a traffic violation is occurring, and the system further comprises a processor for receiving that information and for outputting control signals to control the mirror to thereby adjust the position of the mirror so as to reflect illumination from the lane in which the violation is occurring so the camera captures images of the violation in that lane.
• In another embodiment the reflecting system comprises a plurality of fixed mirrors, each for reflecting illumination from one of the plurality of lanes to a portion of an image capture component of the camera.
• The violation detecting system may comprise an inductive sensor for sensing when a red light phase of a traffic signal is present; and a vehicle detector for detecting when a vehicle is present in a specified portion of the road.
• The inductive sensor may be mounted in proximity to an electric wire for supplying electricity to activate the red light phase of the camera.
• Thus, in one embodiment the sensor detects electricity flow through electric wire which supplies current to the red light of a traffic signal. However, the sensor could be for detecting current flow to the green light or the amber light so that the red light phase is determined when there is no sensed current flow to either the green light or amber light of a traffic control signal.
• The vehicle detector may comprise at least one ranging laser per lane for detecting the presence of the vehicle.
• The vehicle detector may comprise at least two ranging lasers per lane so that the lasers cannot only determine the presence of the vehicle, but also the speed at which the vehicle is travelling.
• However, in another embodiment, the vehicle detector may comprise a camera mounted perpendicular to vehicle flow along the road.
• In one embodiment, the camera has a source of illumination for illuminating the said any one of the lanes so that the illumination is reflected back from the said any one of the lanes by the reflecting system.
• The camera may have a fixed lens mounted between the camera and the reflecting system.
• The source of illumination may comprise an infrared laser mounted on the camera and directed at the reflecting system for providing infrared illumination to illuminate the said one of the lanes.
• The system, according to one embodiment, may include storage for storing images captured by the camera and for identifying images which relate to a violation detected by the violation detection means so that the images associated with the violation are identifying and can be processed to provide evidence of the violation and also identify the vehicle associated with the violation.
• The system may include storage for storing images captured by the wide angled camera and for identifying images stored in the storage and which relate to the violation detected by the violation detection means so that the images associated with the violation are identifiable and can be processed to provide a wide angle view of the violation.
• The system may also further include at least one camera for capturing images of a driver of the vehicle, and a storage for storing the images, the processor also being for identifying images captured by the at least one camera and for identifying images captured by the at least one camera and which relate to the violation detected by the violation detection means so that images of the driver of the vehicle associated with a violation are identifiable and can be processed to provide evidence of the identity of the driver of the vehicle associated with the violation.
• The system may further comprise a temporary storage for continuously storing images taken by the fixed camera; and a processor for identifying those images in the temporary storage which are associated with the violation so that those images associated with the violation can be processed to provide evidence of the violation.
• The system may still further comprise a secondary storage for receiving the images associated with the violation from the temporary storage, and for storing the images which are associated with the violation.
• The system may also still further comprise a communication link for communicating images stored in the secondary storage to a central facility for processing to provide evidence of the violation.
• This aspect of the embodiments further provides a dome camera assembly for a traffic violation system comprising a housing having a dome; a fixed camera mounted in the housing for monitoring a plurality of lanes of a road through the dome; and a reflecting system in the housing for selectively reflecting illumination from any one of the plurality of lanes to said fixed camera.
• In one embodiment, the housing has a cool chamber in which the camera is mounted and a warm chamber defined by at least part of the dome, the reflecting system being located in the warm chamber, and a heat transferring medium arranged for transferring heat generated by the camera from the cool chamber into the warm chamber.
• The heat transferring medium may be a Peltier heat transfer layer which separates the cool chamber from the warm chamber.
• According to another embodiment, the camera has a lens which is arranged in the warm chamber and in optical communication with the camera through an opening in the Peltier layer.
• The reflecting system may comprise a mirror and an adjusting mechanism for moving the mirror so that the mirror reflects illumination from the said any one of the lanes to the camera, in response to detection of a traffic violation in any one of the lanes so the camera can capture images of the violation occurring in that lane.
• In another embodiment, the reflecting system comprises a plurality of fixed mirrors, each for reflecting light from one of the plurality of lanes to a portion of an image capture component of the camera.
BRIEF DESCRIPTION OF THE DRAWINGS
• Embodiments will be described, by way of example, with reference to the accompanying drawings in which:
• FIG. 1 is a view illustrating an embodiment of the traffic violation system according to the embodiment which is used for red light traffic violations;
• FIG. 2 is a diagram similar toFIG. 1 of a system used for speed violations;
• FIG. 3 is a schematic diagram of the system used inFIGS. 1 and 2;
• FIG. 4 is a flow chart relating to initial set up or calibration of the system according to the embodiments;
• FIG. 5 is a flow chart illustrating operation of one embodiment of the system applicable to red light violations;
• FIG. 6 is a flow chart illustrating operation of another embodiment;
• FIG. 7 is an overview of a violation processing system of one embodiment;
• FIG. 8 is a block system module diagram of the embodiment ofFIG. 8;
• FIG. 9 is a flow chart illustrating operation of the embodiment ofFIG. 7;
• FIG. 10 is a plan view of an intersection having a traffic violation detecting system according to a further embodiment;
• FIG. 11 is a view of a camera used in the embodiment ofFIG. 10;
• FIG. 12 is a view of part of the components of the camera ofFIG. 11;
• FIG. 13 is a view of an alternative arrangement to that shown inFIG. 12;
• FIG. 14 is a view of a fixed mirror system arrangement according to one embodiment;
• FIG. 15 is a view of the mirrors ofFIG. 14 in plan;
• FIG. 16 is a view of a pixel array of a camera used in one embodiment;
• FIG. 17 is a view of the same array as inFIG. 16 except rotated 90°;
• FIG. 18 is a view of a laser ranging system for detecting the presence of a vehicle according to this embodiment; and
• FIG. 19 is a block circuit diagram of site computer according to this embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
• With reference toFIG. 1 anintersection10 which is controlled by traffic signals12 (only two of the signals shown for ease of illustration) is comprised of intersecting roadways A and B. The roadway is marked withstop lines14 and16 (only those associated with the roadway A being shown) where vehicles will stop when a red light signal is displayed by the traffic signals12. The embodiment shown relates to a left side of the road driving environment such as that which exists in Australia. Obviously, the stop lines14 and16 are on the other side of the roadway in a right of the road driving environment such as that which exists in the United States of America. It should be understood thatFIG. 1 is only showing a system for monitoring traffic flow in one direction along the roadway A. Additional systems can be used to monitor the traffic flow in the opposite direction on the roadway A and also in the two direction of roadway B if desired. The system according to this embodiment is mounted on apole18 and apole90 which may include existing poles or other road infrastructure, or specially installed poles. Thepole18 mounts awide angle camera20 which can monitor the entire intersection of the roadways A and B as shown by thearea22 inFIG. 1, and including at least one of thetraffic signals12 so that the image captured by thewide angle camera20 includes the red light, amber light, and green light associated with the traffic signals12.
• However, if desired, or necessary, not all of the lights of the traffic signal need to be detected. The purpose of detecting the light to thetraffic signal12 is to determine a violation period such as when a red light signal is displayed as will be described in more detail hereinafter. Thus, if desired or necessary, only the red light of one of thetraffic signals12 need be in the field of view of the wideangled camera20. Furthermore, the violation period can be from commencement of an amber light to the end of the red light phase of the traffic signals, or some other desired period defined by changes in the lights of the traffic signals. Further still, thetraffic signals12 need not be monitored by the wide angle camera which also captures images of the region under surveillance. Depending on the size of the intersection or on other circumstances, a separate dedicated camera (not shown) which only captures images of thetraffic signals12 may be provided in order to allow the violation period to be determined.
• Thepole18 also mounts narrow angle orlane cameras30 each of which monitors or images one of the lanes of the roadway A. In the embodiment shown, the roadway A has two lanes in each direction and therefore twolane cameras30 are provided. If more than two lanes are providedadditional lane cameras30 are utilized. Thepole90 mounts afurther camera91 which is directed perpendicular to the flow of traffic along the roadway A.
• Thecameras20 and30 are connected to asite computer40 which is housed in a roadside cabinet or the like.
• Thecameras30 therefore monitor part of the intersection which is monitored by thewide angle camera20 and the parts monitored by the twocameras30 are identified by thereference numerals31 and33. Thecameras20 and30 are off the shelf digital or video cameras which take images in low lighting conditions and have an auto iris to adjust for different lighting conditions. Typically the cameras have a pixel resolution of 768 by 576 and sustainable imaging rate of twenty five frames per second or better.
• Traffic movement through the intersection (of roadways A and B) is monitored by thenarrow angle camera91 mounted onpole90, perpendicular to the roadway A. This camera monitors a section of the roadway identified by numeral92 inFIG. 1. Thecamera91 is also connected to thesite computer40.
• As shown inFIG. 3 the cameras30 (three shown inFIG. 3) and thecamera20 are connected to thesite computer40. Thecomputer40 includes adata controller50 which is powered by amain power supply52.
• Thedata controller50 includesmemory buffer54 which stores images captured by each of thecameras20 and30 and aprocessor56 which determines when a traffic violation has occurred and identifies the images stored in thememory buffer54 and transfers those images tohard disk58 so that only the images associated with the violation are stored on thehard disk58. Thehard disk58 is connected to a wireless communication link60 (or other communication link such as an Internet link) so that the data relating to the images stored on the hard disk can be transmitted to a central facility for further processing to provide a number of images which relate to the violation and also to identify the number-plate of the vehicle associated with the violation so that an appropriate penalty notice can be issued.
• A global positioning system (GPS)93 is connected to the buffer and stamps each image with an independently sourced date, time and location coordinates in order to identify the time and location of the event. The GPS system obviously obtains this data from satellites, as is conventional, in order to provide a location reference and this, together with the time reference produced by theGPS system93, enables independently verified time and location data to be included to precisely identify the location of the event which is recorded by the system, according to one embodiment.
• In the some embodiments, theprocessor60 is equipped withsufficient buffer memory54 for temporary storage of a sufficient number of images taken by both thewide angle camera20 and thelane cameras30 so as to provide sufficient evidence to cover one or a number of simultaneous violations and to provide the image sequence(s) to prove the violation(s). Thewide angle camera20 will capture images showing the violation, that is a vehicle moving through the intersection when the red light signal is displayed and thelane cameras30 will take images of the vehicle in the lane concerned so that those images can be processed to determine the number plate of the vehicle concerned so the vehicle can be identified and the appropriate penalty notice issued.
• In this embodiment theprocessor56 analyzes the images taken by thecamera20 so that a change in the color of the red light of thetraffic signal12 can be determined and therefore the commencement and end of the red light traffic phase of thesignal12 is determined. The system also includes a trafficmovement detection section94 which is also connected toprocessor56. Thedetection section94 analyzes the images taken by thecamera91 to identify movement of traffic through the intersection during the red light phase of the traffic signal. If traffic movement through one of the lanes of the roadway is determined during the period of the red light phase, thesection94 triggers a traffic violation to be captured by thedata controller50. The images which are associated with that violation are then transferred from the memory buffers54 to thehard disk58 so that a sequence of images captured by thewide angle camera20 showing the vehicle moving through the intersection and also at least one image captured by one of thelane cameras30 which show the vehicle in close up are also captured. Those images are transmitted via thewireless communication link60 to a central facility where the images can be developed or printed to provide evidence of the violation and also the images are inspected so that the number-plate of the vehicle concerned can be determined so that the appropriate penalty notice can be issued.
• In other embodiments, rather than detect the vehicle by virtue of analysis of images to determine the movement of a vehicle in the images, the image analysis equipment may be provided for detection or recognizing a license plate of a vehicle, so that if a recognized license plate of a vehicle is seen in the image in the appropriate time zone indicative of the red light phase, a determination is made that a particular vehicle is present.
• Some embodiments enable relatively inexpensive cameras to be used which can operate in effectively very low lux conditions, so supplementary flash illumination is optional even at night. If lighting conditions are insufficient for operation of the cameras for any reason light intensifiers or infrared illuminators could be used in the system to enable images to be captured and processed to identify a violation.
• As is apparent from the above description, afurther camera91 is used to determine movement of traffic through the intersection during the red light phase of the traffic lights. However, one of theother cameras20 or30 could be used to perform this function. Thecamera91 is arranged perpendicular to the flow of traffic, and therefore, is able to more easily monitor movement of traffic because a movement will cross the path of the camera rather than move in the general direction of the field of view of the camera. Thus, processing of images to determine movement of a vehicle through the intersection is easier to perform with thecamera91 rather than by use of thecameras20 or30.
• In order for thecamera91 to determine that a vehicle has crossed thestop line14, a reference image is created based on histogram pixel values over a number of frames. The reference image is built up whilst traffic is moving, thereby minimizing the chance of vehicles becoming part of the reference frame. The reference frame is continuously updated over time with new images captured by thecamera91, adding to the body of data which is used to establish the reference image and earlier images being discarded.
• The reference image is provided with a plurality of predefined trigger points and a violation is determined by comparing a captured image with the reference frame such as by simply subtracting the current image from the reference frame. If the comparison of the current frame with the reference frame determines something in the current frame at the predetermined trigger points, then an event is generated to show a violation has occurred.
• By continuously updating the reference frame over time, changing conditions are automatically compensated for. That is, for example, if ambient light conditions change or a shadow comes over the region, such conditions will be built into the reference frame as the reference frame is continuously updated.
• Furthermore, the way in which the reference frame is built up can change depending on the time of day. For example, at night the reference frame can be built up slightly differently to take into account vehicle headlights. The image which is associated with a violation is determined by thecomputer40 by the time reference which is established by theGPS system93. At the time of determining a violation event, theGPS system93 enables a time reference to be created. The images which are captured by the cameras also have that time reference stamped on them, as has been previously explained. Thus, by knowing the time of the violation, the image which corresponds to that time can be transferred from thebuffers54 to thehard disk58, together with a number of images on either side of that particular image, so that a set of images showing the violation can be retained. The images which are retained are those from thewide angle camera20 and also thenarrow angle cameras30. If desired, the images which are captured by thecamera91 can also be retained.
• FIG. 4 is a flow chart illustrating initial calibration or set up of the system ofFIG. 1. The system ofFIG. 1 is set up via a graphical user interface operating on a laptop that can be connected to thecomputer40. The software will allow the operator to take test shots using thewide angle camera20. On the test image captured by the operator the operator will define the position of the red signal heads (that is a red light) on thesignals12 by drawing a box, and defining the position of each of the red, green and amber signal lights. The operator will also draw a line to define the position of thestop line14 on the image and will draw a series of lines to define each of the lanes of the roadway that are to be monitored.
• Thecamera91 is also calibrated in the same manner as described above and shown inFIG. 4. A test shot is taken by thecamera91, and on the test image which is captured, the operator will define the position of thestop line14 and also each of the lanes which can be seen in that image. The operator will also identify a number of reference locations in the image which define trigger points to enable an indication of movement of a vehicle in captured images by thecamera91 to be determined so that the speed of the vehicle moving past thestop line14 can be estimated.
• FIG. 5 is a flow chart explaining operation of the system ofFIG. 1. Each frame taken by the wide angle camera is examined by the processing software to identify the status of the traffic signal. The color pixels in the area defined by the setup system to identify the position of each of the red, green, and amber signal lights are analyzed and a determination will be made of the current phase. Each of the areas delineated by the setup software to represent the traffic lanes will be compared frame by frame. A determination will be made if movement is present during the red signal phase and if the movement continues past thestop line14. The lane in which the movement is detected will also be recorded.
• In the event that a movement beyond thestop line14 is detected during the red light traffic phase, the images taken by the wide angle camera20 (both before the point of detection and after the point of detection) will be retained and transferred from thebuffer54 to thehard disk58. The images taken by theappropriate lane camera30 are also retained and stored in the same manner. The images of the wide angle camera and the lane camera pertaining to the one event will be linked by a suitable identification code and additional information including the GPS sourced time, date, location, lane, and approximate vehicle speed will be appended to the event images as a total image and data set. The data sets can be encrypted and also digital signature and compression algorithms can be used to compress the data and the data can then be transmitted by thecommunication link60 to processing centre where the images can be decrypted and viewed for adjudication, verification, tamper validation, and traffic penalty notice issuance.
• As shown in the flow chart ofFIG. 5, if the traffic signals are not in the red light phase, then any event which shows traffic movement through the intersection in the appropriate direction is ignored. If the red light phase is current, then any vehicle which moves through the intersection in the direction of the red light triggers an event which causes the captured images to be transferred to thehard disk58. The system may retain at least two of the images prior to triggering of the event. That is, first detection of the vehicle crossing theline14 during the red light phase of the traffic signals, the image associated with that actual event (i.e., the image showing the vehicle crossing the line14), and at least two images subsequent that event so that a number of images are provided, showing the camera approaching theline14, reaching theline14, and then passing into the intersection during the red light phase of the traffic signals. The GPS system, as previously noted, stamps the images with the location, date, and time of the event.
• In another embodiment, the approximate speed of the vehicle, as the vehicle passes through theintersection14, is also recorded. This is done by analysis of the images from thecamera91. The determination of the speed need not be as accurate as would be specified if the violation being detected was actually a speed violation rather than a red traffic light violation. However, even with a red traffic light violation, some indication of the speed of the vehicle may be specified in some jurisdictions. The speed of the vehicle in the embodiment ofFIG. 1 is therefore determined by tracking the vehicle movement from frame to frame in the images captured by thecamera91, over a predefined distance on the road. Assuming that the frame rate is 50 half-fields per second, an estimation of the speed of the vehicle as it runs the red light can be made. The image captured by thecamera91 may have predetermined location points identified in it which can be compared with the position of the vehicle in the images so that an indication of the distance the vehicle has moved from one frame to the next frame can be determined.
• FIG. 2 shows the system used for detecting speed violations. In this embodiment a region of a roadway C is monitored bywide angle camera20 and each of the appropriate lane ways of the road C are monitored bylane cameras30. As in the earlier embodiment thecameras20 and30 are connected tosite computer40. The regions monitored by thecameras20 and30 are shown by thereference numbers81 insofar as thecamera20 is concerned and thereference numbers82 and83 insofar as thecameras30 are concerned.
• Initial set up in this embodiment is the same as that described with reference toFIG. 4 except that obviously thetraffic signals12 are not identified and the regions which are identified are the regions of the roadway monitored by thecamera20 and the specific lanes monitored by thecameras30. Images are captured in the same way as described with reference toFIG. 1 and the determination for a speed event is made by an external speed measuring device such as Doppler radar or laser speed measuring device. The lane in which the vehicle is travelling is determined in the same manner as described with reference toFIGS. 1 and 3 to5. When the speed measuring device detects a vehicle or vehicles exceeding the threshold speed which has been set by an operator, a number of images from both the wide angled camera and the lane cameras30 (both before and after the speed event) are retained and stored together with information that include date, time, event location, direction of travel, and vehicle speed also lane information. This data is transmitted by thelink60 in the same manner as described above so that the images can be processed to produce a penalty notice.
• Since images are continuously captured by thecameras20 and30 in both of the embodiments described above and are stored intemporary buffer memory54, it is not necessary to provide an intrusive vehicle detection system such as detectors in the roadway or to link the system to the traffic signals in order to provide a trigger to commence operation of the system to capture a violation. Rather, images are continuously captured and are processed so that, in the case of red light violation, the violation can be determined from processing, and those images associated with the violation are retained and transmitted for penalty note issuance, and in the case of a speed violation, when the speed detection equipment indicates a violation, images of the continuously captured images are then transferred to thehard disk58 for transmission to the central facility.
• As in the previous embodiment, the time, date, and location of the event are stamped on the images which are captured by theGPS system93.
• FIG. 6 is a flow diagram of a further embodiment in which an accident is detected and which enables images of the accident to be captured to provide evidence of the accident.
• Referring firstly toFIG. 1, adirectional microphone100 is mounted on thepole18 or in any other suitable location for monitoring ambient sound from the intersection. Themicrophone100 is connected to theprocessor56, as is shown inFIG. 19. Theprocessor56 is provided with sound wave patterns indicative of the noise of an accident, and these sound wave patterns are stored in memory to provide reference patterns for determining if an accident has occurred at the intersection. Themicrophone100 continuously monitors the ambient sound from the intersection and the sound wave pattern detected by themicrophone100 is processed and continuously compared with the sample sound patterns stored within thedata controller50.
• As explained with reference toFIG. 6, if the comparison with the ambient sound received by themicrophone100 is not consistent with the stored patterns in thedata controller50, then the event is ignored and images captured by thecameras20 and30 are not passed to thehard disk58. If themicrophone100 detects a sound pattern consistent with one of the stored sound patterns within thedata controller50, this is taken as an indication of an accident within the intersection and an event is triggered, as is shown inFIG. 6. This causes the wide angle image captured by thewide angle camera20 to be transferred to thehard disk58. Also, at least two images prior to that image are also transferred to thehard disk58, and two images subsequent to that image are transferred to thehard disk58. Thus, the sound pattern indicative of a traffic accident causes the retention of images in the same manner as a red light violation or speed violation, as in the earlier embodiments. These images may be captured concurrently with or instead of speed violation images or red light violation images. Thus, the facts of the event are therefore captured and recorded, which can provide information as to the nature and cause of the accident in any further proceedings.
• It will be apparent from the above description that theprocessor56 forms the functions of processing the images taken by the camera in order to determine the red light phase and also to determine whether a vehicle is present in the intersection during the red light phase, as well as processing ambient sound to determine whether an accident has occurred, and then identifying the relevant images for transfer to thehard disk58. Although in one embodiment, asingle processor56 is provided to perform all of these functions, thedata controller50 could include several separate processors, each of which performs only one or some of the functions referred to above. Thedata controller50 may therefore effectively include a single board in which all processing is performed, or a number of separate processing boards which are suitably coupled together if necessary to perform of the above-mentioned functions.
• The images captured by the cameras can also be analyzed to enable vehicles to be classified. That is, by image analysis, the type of vehicle, i.e., car, truck, motorcycle, etc., can be determined to provide some statistics on the nature of the vehicles which are using that particular part of the roadway. Furthermore, some embodiments may also be able to determine a particular traffic light sequence which may allow vehicles to travel through the intersection, such as turning arrows, flashing red or amber lights indicating that a vehicle should approach the intersection with caution but may cross the intersection during the period of the flashing lights, so that those traffic signals do not prompt a violation to be recorded.
• In another embodiment, traffic violations which relate to failure to pay at tollways or tollbooths associated with a roadway are detected. In most modern tolling systems, vehicles carry electronic devices which are automatically detected and recorded when the vehicle passes a toll station on the roadway. In conventional systems a single photograph of a vehicle passing the tollway is captured to enable the vehicle to be identified if the electronic device is not detected. In the present embodiment, the cameras are arranged in a similar manner as described with reference to the earlier embodiments to capture a sequence of photographs continuously. In the event of an electronic device not being detected, the time of detection is recorded via the GPS system as in the earlier embodiments, and the sequence of images associated with that violation are therefore retained as in the earlier embodiments, to provide evidence of the infringement and also to enable the vehicle to be identified. This embodiment has particular advantages in tollbooth situations, because in some instances it is very difficult for a single photograph taken from a tollbooth station to properly identify a license plate of the vehicle. The fact that the present embodiment enables a sequence of photographs to be taken, which include photographs of the actual violation, together with photographs prior to and following the violation, provides more images from which the vehicle number plate can be identified.
• Some embodiments also provide a method and system for processing violations which are captured by the systems described with reference toFIGS. 1 to 6, and the tollway violations described above. The embodiment ofFIGS. 7 to 9 enables violations to be processed by a relevant department, such as a police department, information to be assembled for preparation of fines or court proceedings, and also for monitoring and review by authorized users of the system, such as police department, court officials, city officials and the like. The system also enables individuals who have been forwarded a violation notice to inspect the images associated with that violation should they so desire.
• The embodiment ofFIGS. 7 to 9 provides real time communications between all field systems of the type described with reference toFIGS. 1 to 6, and one or more central databases120 (seeFIG. 7) and all users and managers concurrent access to data by different users.
• Once data is stored within the system, the only thing that changes is its status, e.g., the status of a particular set of data may be altered from “pre-verified” to “accepted”, at which point it becomes available for police authorization. The system may be accessed by different classes of authenticated users (including for example, personnel associated with the operating system, client personnel such as police officers, court officials, verification operators and city managers, or the individual citizens who may wish to view evidence of their traffic fine via the Internet). Each user is authenticated at login and is automatically granted a particular range of privileges as appropriate to their role. The system includes aweb server121 which acts as the main entry point for all external requests for information and updates and allows browser-based, interactive access for authenticated users in any location. This allows a distributed infrastructure which can be accessed globally with full authenticated security. Thedatabase120 is contained within aviolation processing engine130 which also includes business logic, represented byreference132, which relates to the protocols and manner with which different clients may wish to deal with information concerning a violation in their particular jurisdiction. For example, a single database could be utilized for storing and processing violations captured in a number of different cities. Each of those cities may specify a different protocol for forwarding fine notices, for prosecution purposes or otherwise. The violation processing engine therefore enables each of the specific users to process data relating to their particular violations in a specific way applicable to them. Thus, a single database or set of databases can be utilized without the need to specifically tailor a specific database for each individual user's requirements. Thus, theviolation engine120 contains the broad range of business logic necessary to perform traffic camera office operations in respect of processing red light running, speeding and toll violation evidence. These operations include: reviewing evidence (images and data) for each alleged event to identify or verify violation events that have breached the relevant authority's traffic law/traffic code; making verified violations available for authorization—and possible electronic signature—by jurisdiction officials (usually sworn police officers); ticketing (i.e., printing and mailing authorized warning letters, traffic fines/notices, or summonses); tracking fine payments; producing reports to users of the system; producing evidence for the courts relating to specific traffic violation or events, including all event images (that is, the multiple set of images captured by the cameras and obtained when an event is determined, and which show the scene of the incident, the vehicle license plate and also the driver ID or face if requested); producing data sheets relevant to the event; and creating an electronic audit trail (in place of sworn chain of custody statements that are requested when officers use film cameras).
• Anevent server140, which is may be in the form of a large scalable database server, is provided and onto which primary evidence (i.e., the images and data captured by the system ofFIGS. 1 to 6) is loaded. Theevent server140 received the data from thelink60 inFIG. 3 by way of Internet connection or in any other suitable manner. The event server maintains the integrity of all primary evidence because, for example, any image modification (such as gamma correction) is only performed on duplicate images that have been received from the server for processing. Areport server150 is connected to the event server and also to theweb server121 to enable memory intensive reporting. Anarchivist160 is also provided which purely rechecks the status and age of all events stored on the event server, against the relevant client's agreed business rules, and uses this information to remove outdated data and images and archive them.
• FIG. 8 is a systems module diagram of the system described with reference toFIG. 7. The module ofFIG. 8 includes amodule200 for receiving data and images from thesite computers40 and, as previously described, this information may be transmitted by way of Internet connection or by any other suitable method. Themodule200 therefore receives information relating to a particular customer which may be a city authority, or the like. The data is received by aninterface201 which converts the data, if necessary, into a particular format which can be read and processed by the remainder of the system ofFIG. 8. The data from the various systems is automatically regularly polled so that the violations images are received by the system ofFIG. 8. The images and data are then supplied to theevent server140 fromevent interface201,data interface202, which in turn receives data transformed bymodule204. Theevent server140 includes an image server module141 and adata server module142 which are connected to thebusiness process module132 which contains the protocols relating to a particular customer to enable the information relating to a violation to be compiled and treated in accordance with the business rules of that particular customer. Thus, images and data may be archived by thearchivist160 in accordance with the rules of a particular customer.
• Once images of a particular event have been inspected and a violation deemed to have occurred, information relating to the owner of the vehicle involved in the violation needs to be obtained. This is received from the relevant authorities such as avehicle registration authority300. The database at theauthority300 is therefore automatically interrogated by the system ofFIG. 8 to provide the license plate details of the vehicle involved in the violation. If necessary, the data is transformed bymodule165 into a format which can be understood and read by the database at theauthority300. Once the information relating to the data has been transformed, it is supplied to theauthority300 viainterface module156 after being formatted into a customer format inmodule157. Details relating to the owner of the vehicle are retransmitted back viamodule156 and are transformed bymodule165 back into a format which will be understood by the system ofFIG. 8 and into the relevant format requested or specified by the specific user. The information may be then forwarded to aprint server161 for printing images of the event and to anotice module162 which creates a notice for printing, such as a fine or the like, which is forwarded to the owner of the vehicle. Thebusiness module132 is also connected to areport generator module163 which enables specific reports to be generated relating to the infringement activity detected by various systems within the user's infrastructure. Standard reports according to the specifications of a specific customer may then be generated bymodule164.Web interface170 enables authorized users and civilians to access the system so as to process violations or view a violation relevant to a particular citizen. Theweb interface170 enables a user to logon to the system viamodule172. The user's authentication code and logon details will therefore define the access the user has to the system ofFIG. 8. For example, if an authorized officer, to determine whether a violation has occurred, such as a police officer, town clerk or other authorized personnel, logs on, that person will be able to access images relating to the jurisdiction for which that person has responsibility, and determine whether a violation has occurred from those images. For example, the authorized person logs on atstep171 and queries all events in that person's jurisdiction atstep172. The events are then compiled and displayed on the user's screen atstep173 so that the user can determine whether a violation has occurred. If this is the case, the registration details of the vehicle are determined by accessing theauthority300 in the manner previously described. As explained hereinafter, requests for registration details may be batched for automatic look up at a later date. An event report, such as a summons, fine or the like, may then be generated and forwarded to the vehicle owner, as also previously described. Theweb interface170 also enables the authorized person to then go to thenext event174 and continue the process until all recorded events have been processed and verified. Atstep175, the images relating to a particular event can be inspected in turn to observe the sequence of images which relate to the event and also the details of the license plate of the vehicle concerned.Module176 enables an update of the system to show that fines have been paid or that no activity has occurred and that court proceedings should be instigated or any other activity which may be specified by a particular customer.
• Thebusiness process module132 may also be connected to other authorities, collectively shown at303, which may need to interrogate the system to determine particular events applicable to them.
• Thus, all information stored in theevent server140 may be accessed dynamically by any authenticated user according to the controls inherent in their authentication. For example, once violation images and violation data have been stored in the event server, they are available to any authenticating process officer for verification purposes. Once the operator has logged in and defined their verification request, the system displays images and data on their PC screen. Operators can click onto an image to enlarge if desired. They may also request that a full image set (e.g., all license plate images for a particular violation) be furnished if desired. License plate details may be supplied to the event server by the field OCR systems, or may be entered or edited manually by the operator at this stage.
• Operators may accept/reject evidence for a particular event or end it or mark it for review by a supervisor or another operator. Only when evidence meets the client's legal and business rules are violations accepted and further processed by the system.
• Verified violation events (containing the license plate number of the vehicle) are batched for automatic look-up at theauthority300 which automatically populates the registered owner information on the appropriate notice which is presented for authorization so that all relevant information is available for review by the authorizing officer.
• Authorized users may also have secure, dynamic, browser-based access to data held in the system (at their particular privilege level) for any computer with Internet access. They may login using their assigned user name and password—and additional security, e.g. an USB token (which is inserted into the appropriate port of the computer), request immediate access to evidence for defined classes of verified violations/particular violation event, for immediate display on screen, accept or reject the violation with a single click, request image enlargement, request multiple image set images for each display image and scroll through these, authorize issue of the relevant letter notice and electronically sign if desired, request standard system reports by themodule164.
• The system generates a print file for printing and mailing as per themodules160 and162 which may be warning letters, fine notices, notices to appear or summonses. These documents may display relevant violation images if desired, and are customized to meet the customer's legal specifications. All mailing details are automatically recorded by the system.
• Standard reports include, for example, monthly reporting for: the total number of violations recorded for the month; the number of letters/notices of violation issued; the number of letters/notices of violation not issued; break down by reason for non-issuance; the number of camera operating hours; and the number of violations recorded per camera operating hour.
• As described with reference toFIG. 9, the database may be updated and maintained to show that various fines which have been issued have in fact been paid and therefore can be struck out of the system. The system may also generate official summonses for unpaid violations, as previously described, and also compile evidence packs for use in court, allow ad hoc viewing by police departments of past or current violations, and report on a monthly or random basis to relevant authorities.
• An alternative embodiment to that shown inFIGS. 1 to 4 is shown inFIGS. 10 to 20.
• Referring toFIG. 10, an intersection is shown which has a road C which may contain four lanes L1, L2, L3, and L4.
• It should be noted that the intersection shown inFIG. 10 is applicable to right hand side motor systems such as that present in the USA.
• The system includes awide angle camera20 which is the same as thewide angle camera20 previously described with reference toFIGS. 1 to 4, for capturing images of the entire intersection. Adomed camera assembly199 having a fixedcamera210 is provided for capturing narrow angle images of each of the lanes L1 to L4 in which a violation occurs. Thus, in this embodiment, instead of providing a separate camera for each of the lanes, only one camera is provided to monitor a plurality of lanes. The intrusion of a vehicle into the intersection when a red light phase of a traffic control signal is present may be monitored bycamera91 which is the same as thecamera91 described with reference toFIGS. 1 to 4. However, in this embodiment, the vehicle detection is performed by ranginglasers250 and251, which will be described in more detail hereinafter.
• Afurther camera211 may be provided for capturing images of the face of a driver when a violation occurs. Thecamera211 may be identical to thecamera210 and operate in the same manner or, alternatively, a plurality of separate cameras for each of the lanes L1 to L4 can be provided for monitoring each of those lanes to capture images of a driver when a violation occurs in any one of those lanes.
• Thecameras20,210,91 and211 are mounted on poles in the same manner as the earlier embodiment. The ranginglasers250 and251 are also mounted on poles so as to be located above the intersection, as will be described in more detail hereinafter.
• FIG. 11 shows theassembly199 which has ahousing261 which includes adome262. Thehousing261 is divided into a cool chamber263 and awarm chamber264 by a Peltierheat transfer layer265. Thelayer265 has anopening266 and thecamera210 is provided with alens267 which locates in thewarm chamber262 and either projects through theopening266 to be in optical communication with thecamera210 or is in optical communication with thecamera210 through theopening266. Aninfrared laser268 is mounted on thecamera210 for producing infrared illumination to illuminate a respective one of the lanes L1 to L4 with infrared illumination so that the illumination can reflect from the lane and vehicles, etc. in the lane back to thecamera210 so the camera can capture images of the lane and any vehicles in the lane.
• Amoveable mirror269 is provided in thedome262 for reflecting illumination from a respective one of the lanes
• L1 to L4 to thecamera210 so that images can be captured. Thelaser268 points at themirror269 so that the illumination produced by the laser is also directed to the lane to which themirror269 points so thelaser268 provides illumination to, that lane and reflected illumination from the lane is reflected by themirror269 to thecamera210 to capture the aforesaid images. Thecamera210 includes a CCD array301 (seeFIGS. 16 and 17) and the camera generates some heat during operation. As the temperature of the CCD array increases, there is a proportionate increase in the amount of noise in the image captured by thecamera210. Alternatively, if the camera lens and mirror are in a cool environment, the chance of fog developing on the surfaces increases. ThePeltier layer265 which is located between the camera and lens, transfers heat away from the camera and, in particular, the CCD array of the camera to the warm chamber to thereby keep the environment of thelens267 and themirror269 warm. This has the dual effect of creating clearer images on the CCD array and preventing fog from forming on the surfaces of the lens and mirror.
• Themirror269 is moved by a mirror rotation and tilt mechanism schematically shown at270 inFIG. 11.FIG. 12 shows one embodiment of the mechanism which comprises afirst motor271 and asecond motor272. Themotor271 drives screw threadedshafts273 and274 which are screw threaded tolugs275 and276, which in turn are connected to mirror269. A fixed ball joint278 is connected to one of the other corners of themirror269, and aspring277 is provided for biasing the mirror by contacting the mirror at about the midpoint of the triangle formed by the corner at which the ball joint278 is connected and the corners at which theshafts273 and274 are provided. The other end of thespring277 is fixed. When themotors271 and272 return thelugs257 and276 to a home position, thespring277 biases themirror269 to its own home position. In this embodiment, the mirror is rectangular and thelugs275 and276 are connected to opposite corners of the mirror and the ball joint278 to one of the other corners of the mirror. Themotor271 produces tilt of themirror269 and themotor272 produces pan of themirror269. Themotors271 and272 are controlled byprocessor56 when a violation is detected, so that the mirror is moved to aim at the lane L1 to L4 in which the violation occurs. Thus, that lane is illuminated with illumination from thelaser268 and reflected illumination is reflected by themirror269 to thecamera210 so images of the violation can be captured. If the image captured by thecamera210 needs to be enlarged, thelens267 can zoom to the appropriate degree.
• As will be apparent from a consideration ofFIG. 11, as the motors are activated, the screw threadedshafts273 and274 are rotated, allowing either or both corners of themirror269 to be raised or lowered. This will allow the mirror to be aimed in the appropriate location. A feedback system (not shown) may also be provided to let theprocessor56 know the position of the mirror. The feedback system can also move the mirror back to a home position so as to minimize the amount of movement necessary to point at any one of the lanes so that the mirror can be quickly moved when a violation occurs, so the violation is captured by thecamera210.
• In a further embodiment shown inFIG. 13, themechanism270 comprises apan disk280 which has a pair ofsupports281 and282 in which mirror269 is journaled byaxle283. Theaxle283 is rotated bymotor284. Thepan disk280 has acentral hole285 through which thecamera lens267 andcamera210 can view themirror269. Thedisk280 is rotated by a motor andmotor shaft280awhich drives agear280bwhich hasgear teeth280cand mesh withgear teeth280don thedisk280. In another embodiment, thedisk280 could be driven by a belt which in turn is moved by a motor and pulley arrangement (not shown). Thedisk280 is rotatable to provide pan action and themotor284 can tilt themirror269 to provide tilt action.
• The mechanism shown inFIG. 13 provides a wider range of movement than that shown inFIG. 12 and therefore may be more suitable for particularly wide roads having a larger number of lanes.
• Once again, thetilt motor284 and the rotation of thepan disk280 are controlled by theprocessor56 when a violation is detected so the mirror points at the appropriate lane so the violation can be captured by thecamera210.
• FIGS. 14 to 17 show a still further embodiment in which a fixed mirror system formed by a plurality ofmirrors295ato295dare used in place of themirror269 in the embodiments ofFIGS. 12 and 13. This has the advantage that it is not necessary to move the mirrors after installation and proper calibration.
• Each of themirrors295ato295dare mounted on arespective panel299. As is apparent fromFIG. 14, each of themirrors295ato295dare separate from one another. However, themirrors295ato295dcould be joined together to form an integral mirror in which themirrors295atoo295dare angled with respect to one another to reflect light in the appropriate direction to images the lanes L1 to L4. Each of thepanels299 is provided with a screw threadedshaft297 and298 in opposed corners, and one of the corners of thepanels299 between those opposed corners is fixed, as shown byreference260. In order to adjust the position of each of therespective mirrors295ato295dto properly calibrate the alignment of the mirrors, theshafts297 and298 are rotated by motors (not shown) to angle the mirrors so that each of the mirrors reflects the image from one of the respective lanes L1 to L4 onto a portion of theCCD array301 of thecamera210. As an alternative to providing motors to rotate theshafts297 and298, the shafts may be provided with ahandle298aso the respective shafts can be manually rotated to thereby adjust the alignment of themirrors295ato295d. TheCCD array301 is 1280×1024 pixels, according to one embodiment.
• FIG. 16 shows a CCD array in one orientation, andFIG. 17 shows the array rotated 90°. Themirror segments295ato295dare arranged to reflect light from the lanes L1 to L4 onto theCCD array301, as identified by thereferences lane1 tolane4 inFIGS. 16 and 17. Thus, all of the lanes are simultaneously imaged on theCCD array301 with a different part of the CCD array imaging each of the lanes. Since each of the lanes are all imaged on theCCD array301, it is not necessary to move the segmented mirror arrangement295 after it has been initially set up and calibrated, so as to properly reflect illumination from the lanes onto theCCD array301 and therefore no movement of thecamera210 or themirrors295ato295dis needed. The proper calibration and alignment of each of themirrors295ato295dcan be performed when the camera is initially set up by manual adjustment so that the respective reflectingportions299 properly point at their respective lanes so that those lanes are imaged on theCCD array301. For ease of illustration,FIG. 15 shows themirrors295ato295dsubstantially parallel but, in practice, they will be slightly angled to properly point at their respective lanes. Theprocessor56 is programmed to know which parts of thearray301 relate to each of the lanes (or, in other words, which pixels of the array relate to each of the lanes) so that when a violation occurs in one of the lanes, the image created by those particular pixels is used to provide evidence of the violation. The image from the other pixels can be blocked out to preserve privacy of any other vehicle which may be imaged by those pixels. In other words, only the image at the relevant part of the CCD array is extracted to provide evidence of the violation.
• Thelaser268 produces absolute infrared light (non-visible to the naked eye) to act as an external illuminator for the purpose of making a number plate and face of a driver of the vehicle brighter for capture by thedome camera210 and by thecamera211 respectively (if thecamera211 is of the same configuration as the camera210). As will be apparent from the foregoing description, the laser will illuminate whatever the camera is viewing. As the surface of a number plate is highly reflective to coherent laser light, the effect is a much higher contrast and more detailed image for identification in law light conditions.
• However, it should be understood that the laser is mounted on the camera and views the same location as the camera via themirror269, thelaser268 could be mounted separately.
• In order to determine when the red light phase of a traffic signal is present, this embodiment uses an inductive sensor200 (seeFIG. 19) which is clamped to theelectric wire201 which provides electricity to thered light202 of the traffic signal.
• Thus, when electricity is supplied to illuminate the light202, the magnetic flux which is created by flow of electricity through thewire201 is sensed by theinductive sensor200 and a signal is provided online203 to theprocessor56 so that theprocessor56 knows that the red light phase is active and present. When the red light phase finishes, electricity stops flowing and the signal online203 ceases so that theprocessor56 knows that the red light phase is over. Thus, theprocessor56 is provided with information showing when the red light phase of the traffic control signals is present, so that if a vehicle is present in the intersection and travelling along road C, the system knows that a violation has occurred.
• As previously mentioned, thecamera91 can be used to provide an indication that the vehicle is in the intersection, as in the earlier embodiments. However, in another embodiment, ranginglasers250 and251 are provided for detecting the vehicle in the intersection. These lasers also have the advantage that they can easily be adjusted to also provide an indication of the speed of the vehicle so that not only can a red light violation be detected, but also a speed violation detected.
• As is shown inFIG. 18, the ranginglasers250 and251 are arranged above a respective one of the lanes L1 to L4. Thus, each of the lanes L1 to L4 is provided with two of the ranginglasers250 and251. Thelasers250 and251 are angled at predetermined angles marked α and γ inFIG. 18, which may be the same angle or different angles. The lasers are equipped with a ranging device, and hence are ranging lasers allowing them to measure the distance from the laser to any other point. These types of lasers are known and therefore will not be described in detail. However, suffice it to say that the lasers calibrate themselves to the fixed distance to the road surface and remember this distance. If the distance decreases, there is a signal output to indicate that an object (i.e., a vehicle) is blocking the laser beam and the range is recorded. This calculation is done in groups of three pulses at a collective rate of approximately 100 times per second (300 pulses per second). Because the lasers are angled, there is a delay in signal output from the two lasers. Theprocessor56 measures the delay and a speed of the vehicle can therefore be determined. For example, if the beam from thelaser250 is broken at time T1 as shown inFIGS. 18, and the beam from thelaser251 is broken at time T2, the time difference is obviously T2−T1. Since the angles α and γ are known, as is the height of the lasers above the roadway, then the speed of the vehicle can be determined by the time difference measurement.
• Thus, by breaking the laser beams, not only is the presence of a vehicle determined, but also the speed of the vehicle can be determined if desired. When the laser beams are broken and the distance remembered by the lasers changes, the signal is output on line309 (seeFIG. 19) toprocessor56 to thereby indicate that there is a vehicle in the intersection. If this coincides with the red light phase of the traffic control signal, as provided by the signal online203, the image capture process is triggered to thereby identify those images which relate to the violation of all of the images captured by the camera. Thus, only the images relating to the violation are separated out of the continuous images captured by all of the cameras and are stored for providing evidence of the violation and also evidence of the vehicle and person who committed the violation.
• In the case of a moving mirror system as in the embodiments ofFIGS. 12 and 13, as soon as the violation is detected, control signals are output from theprocessor56 on line(s)310 (FIG. 19) to themechanism270 to control themechanism270 so that the camera via the moving mirror, points at the appropriate lane to capture the desired images. Thus, all of the images captured by thecamera210 will comprise images of the carriage way at which the camera was pointed, images showing movement of the camera and then images of the lane in which the violation is occurring and of the violation. Thecamera210 is focused at a part of the intersection so that, as soon as the violation is detected, there is sufficient time for the camera to move to the appropriate lane to capture images of the vehicle in the intersection whilst the red light phase is current to thereby provide evidence of the violation and evidence of the vehicle concerned. Those images are time and stamped recorded as in the previous embodiment, so that a particular set of images associated with the violation can be identified of all of the images captured by thecamera210, and those images can then be transferred and transmitted to provide the desired evidence in the same manner as in the previous embodiment. Thus, once again, images are continuously captured and over time, are simply overwritten as the temporary storage becomes full. When a violation occurs, the images associated with the violation are identified and are extracted for providing evidence of the violation, the vehicle concerned and also of the driver of the vehicle if desired in the same manner as described with reference toFIG. 3. Thus, apart from the modifications referred to above,FIG. 19 operates in exactly the same manner asFIG. 3 previously described, and the same reference numerals inFIG. 19 relate to the same components as described with reference toFIG. 3.
• The method and system for processing violations described with reference toFIGS. 7 to 9 is also used with the embodiment ofFIGS. 10 to 19. Thus, once the relevant images are identified, those images and the violation process occurs as described with reference toFIGS. 7 to 9. Thus, again in this embodiment, of all of the images which are continuously captured by the cameras, a set of images which are associated with a violation are identified and used as evidence. Those images may typically comprise two images showing the vehicle prior to violation occurring, one image clearly showing the violation and two images after the violation to provide a sequence of images showing the occurrence of the violation. Alternatively, only a sequence of images showing the actual violation, such as a sequence of images of a vehicle in the intersection during a red light phase can be provided. By providing a series of photographs, such as six photographs, once again a complete picture of the violation is provided and more images are available to enable proper identification of the vehicle and also of the driver of the vehicle.
• Once again, although certain embodiments have been described with reference to asingle processor56, which performs all of the processing functions previously described, the processor can be made up of a number of separate processors, each for performing various processing functions.
• In the claims which follow and in the preceding description of the embodiment, except where the context indicates otherwise due to express language or necessary implication, the word “comprise”, or variations such as “comprises” or “comprising”, is used in an inclusive sense, i.e., to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments.
• Since modifications within the spirit and scope of the embodiments may readily be implemented by persons skilled within the art, it is to be understood that this invention defined by the following claims is not limited to the particular embodiments described by way of example above.

Claims (20)

1. A system of detecting and recording a traffic event comprising:

a sound monitor configured to receive ambient sound of a roadway region under surveillance;

at least one camera configured to repetitively capture images of the roadway region under surveillance;

a storage device configured to store the images; and

a processor coupled to the sound monitor and configured to:

compare the ambient sound with a pre-determined sound profile indicative of the traffic event;

determine, based on the comparing, an occurrence or absence of the traffic event; and

in response to the occurrence of the traffic event, provide an indication to retain images captured contemporaneously with, and showing at least a portion of, the traffic event.

2. The system ofclaim 1, wherein the sound monitor is a microphone.

3. The system ofclaim 2, wherein the microphone comprises a directional microphone configured to be mounted outdoors atop a traffic signal pole.

4. The system ofclaim 1, wherein the traffic event is a traffic accident.

5. The system ofclaim 1, wherein the storage device comprises a temporary storage device, and the system further comprises:

a secondary storage device configured to receive from the temporary storage device a series of retained images relating to the traffic event, wherein the series of retained images include at least an image captured prior to the traffic event, and at least an image captured after the traffic event.

6. The system ofclaim 1, wherein the roadway region comprises an intersection.

7. The system ofclaim 1, wherein the pre-determined sound profile indicative of the traffic event comprises pre-recorded traffic event sound samples.

8. The system ofclaim 1, wherein the processor is further configured to:

in response to the absence of the traffic event, provide an indication to delete the images.

9. The system ofclaim 1, wherein the at least one camera comprises a wide angle camera configured to capture images of multiple lanes of the roadway region under surveillance.

10. A system of detecting and recording an event comprising:

a sound monitor for continuously capturing ambient sound of a region under surveillance to detect a defined event;

processing means for processing the ambient sound and comparing the captured ambient sound with a pre-determined sound profile indicative of the event;

at least one camera for continuously capturing images of the region;

storage means for temporarily storing the images; and

identifying means for identifying the stored images which are associated with the event so that the stored images can be processed to provide evidence of the event.

11. A method of detecting a traffic event, the method comprising:

repetitively capturing images of a roadway region under surveillance;

temporarily storing the captured images;

capturing ambient sound of the region;

detecting in the captured ambient sound, the traffic event; and

identifying from the stored images, a stored image associated with the traffic event.

12. The methodclaim 11, further comprising:

retaining the stored image associated with the traffic event for evidence of the traffic event in subsequent proceedings.

13. The methodclaim 11, wherein the traffic event comprises a traffic accident.

14. The methodclaim 11, further comprising:

transferring the stored image associated with the traffic event from temporary storage to a hard disk storage device.

15. The methodclaim 11, wherein the step of detecting the traffic event comprises:

comparing the captured ambient sound with pre-recorded sound patterns of vehicle crashes.

16. The methodclaim 15, further comprising:

ignoring a temporarily recorded traffic event that is inconsistent with the pre-recorded sound patterns of vehicle crashes; and

deleting stored data associated with the temporarily recorded traffic event.

17. The methodclaim 11, further comprising:

capturing location, date, and time information corresponding to the stored image associated with the traffic event.

18. The methodclaim 11, wherein the captured images are contemporaneously processed to determine red light violations.

19. The methodclaim 11, wherein the captured images are contemporaneously processed to determine speed violations.

20. A method of storing and managing evidence of traffic violations and events which are detected by a plurality of violation detection and recording systems comprising the steps of:

continuously communicating evidence of traffic violations and events to at least one server;

providing real-time communications between all violation detection and recording systems and the server(s);

providing a database containing information relating to violations detected by the violation detection and recording systems;

dividing the database according to the different access preferences of different categories of authorized users with each user's level of access and functionality being automatically defined by their unique password and log-in process;

allowing browser-based access to information held in the database or databases at a pre-defined level of authority for any authorized user using a computer with Internet connectivity; and

allowing interactive access to and operation of the violation processing system for individual users to perform evidence management tasks specified by the authorities operating the system.

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