AU785266B2 - Traffic violation detection system - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): TRANSOL PTY LTD Invention Title: TRAFFIC VIOLATION DETECTION SYSTEM The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 TRAFFIC VIOLATION DETECTION SYSTEM Field of the Invention This invention relates to a traffic violation detection system for detecting traffic violations such as red light traffic violations or speed violations.

Background Art Traffic camera law enforcement has traditionally used film-based cambers for the detection of speed and redlight 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 eg inductive loops, which detects 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 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 H:\Luisa\Keep\Speci\Transol PR5925 Coplete.doc 12/06/02 3 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 illumination systems have remained fundamentally as for film-based operations.

The fundamental disadvantages of these commonly applied systems are: 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; High construction and maintenance costs (ie 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 cambers are used, communications lines); 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; Where illumination is used (for virtually all film-based or digital cameras) mains power is required at the site to meet the high power H: \Lisa\Keep\Speci\TransoI PR5925 Copletedoc 12/06/02 4 requirements of flash photography; Where digital cambers 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; Purpose built, high-resolution, digital traffic cameras are relatively expensive, adding to costs of traffic program installations and operation.

Summary of the Invention The object of the invention is to provide a system which addresses at least some of the above fundamental disadvantages of conventional systems.

The invention provides a red light traffic violation recording and processing system, comprising: at least one camera for monitoring a region under surveillance; means for supplying time, date and location data to provide an indication of the time, date and location of a violation; 25 a storing means for continuously storing images S• 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 in a violation period; 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 o *with a violation are identifiable and can be processed to provide evidence of the violation and also identify the vehicle associated with the violation; and i processing means for processing images captured H,\Luia\Keep\Speci\Transo1 PR5925 Couplete.doc 16/10/06 5 by a camera to identify changes in the colour of the traffic signals to thereby make a determination of the commencement and end of a red light traffic phase and therefore define the violation period.

This aspect of the invention may also be said to reside in a method of detecting a red light traffic violation, comprising 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; continuously storing images taken by the at least one camera in a storage means; processing images captured by a camera to identify changes in the colour of the traffic signals to thereby make a determination of the commencement and end of a red light traffic phase and therefore define the violation period; detecting a traffic violation in the region under surveillance during the violation period; determining images stored by the storage means and which relate to the traffic violation so that those images can be used as evidence of the violation and also 25 to identify the vehicle associated with the violation; and providing time, date and location data to provide the time, date and location of the violation.

Thus, according to this aspect of the invention vehicle detection systems which detect the vehicle in the region under surveillance are not required because the cameras continuously take images of that region. Thus, it is not necessary to determine if a vehicle is actually in the region and causing a violation in order to trigger the 35 cameras to take an image. Images captured by the wide angle camera can be used to show the violation and images captured by the narrow angle camera can be used to Hs\Luisa1\Keep\Speci\Tranol PR5925 Coaplete.doc 16/10/06 6 identify the vehicle associated with the violation. Since the violation detection means detects when a violation occurs and the images of the continuous captured images which relate to that violation are determined the cameras used can be relatively inexpensive and require no flash units.

Thus, since the system and method of this aspect of the invention do away with the need to provide a detection system in the roadway such as in-ground loops is not required 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 continuously stored.

In one embodiment of the invention the traffic violation being detected is a red light violation.

Further, the cameras can be operated by battery or solar power instead of mains power if desired.

In this embodiment the violation detection means comprises image processing means for processing images captured by one of the said wide angle camera or at least one narrow angle camera to identify changes in the colour of the traffic signals to thereby make a determination of the commencement and end of a red light traffic phase and

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therefore define a violation period. If the violation detection means determines a vehicle in the region under surveillance during that period images stored in the storage means for that period are identified and then processed to provide evidence of the violation and also to •identify the vehicle associated with the violation.

In this embodiment of the invention most preferably a vehicle in the region under surveillance during the red light phase period is determined by the processing means H\Luisal\Keep\Speci\Transo1 PR5925 Complete.doc 16/10/06 7 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.

Preferably the storage means included a temporary storage means for temporarily continuously storing images taken by the wide angle camera and at least one narrow angle camera and 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.

In this embodiment the images stored in the temporary storage means can be deleted, or overwritten, after a predetermined period.

In the preferred aspects of this embodiment the wide angle camera captures an image 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.

Preferably a plurality of narrow angled cameras are utilised for monitoring respective parts of the region so that all parts of the region are monitored by the plurality of narrow angled cameras.

Preferably each narrow angled camera monitors a lane of the roadway.

•C:o Preferably the narrow angled cameras are used to provide S. an image of the vehicle so that the number plate of the 35 vehicle can be identified to thereby identify the vehicle associated with the violation.

o ooo H,\Luial\Keep\Speci\Transol PR5925 Complete.doc 16/10/06 8 Preferably the temporary storage means comprises temporary memory buffers.

Preferably the cameras are off the shelf digital 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.

Preferably the cameras have a pixel resolution of between 768 by 576 (approximately 0.5 Mg Pixel) and a dynamic rage of 60dB and a sustainable imaging speed of at least twenty five frames per second.

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THE NEXT PAGE IS PAGE Ht\Luisal\Keep\Speci\Transol PR5925 Complete.doc 16/10/06 0 10 Brief Description of the Drawings Preferred embodiments of the invention will be described, by way of example, with reference to the accompanying drawings in which; Figure 1 is a view illustrating an embodiment of the traffic violation system according to the invention which is used for red light traffic violations; Figure 2 is a diagram similar to Figure 1 of a system used for speed violations; Figure 3 is a schematic diagram of the system used in Figures 1 and 2; Figure 4 is a flow chart relating to initial set up or calibration of the system according to the preferred embodiments; and Figure 5 is a flow chart illustrating operation of one embodiment of the system applicable to red light S. violations.

With reference to Figure 1 an intersection 10 which is controlled by traffic signals 12 (only two of the signals shown for ease of illustration) is comprised of intersecting roadways A and B. The roadway is marked with 30 stop lines 14 and 16 (only those associated with the roadway A being shown) where vehicles will stop when a red light signal is displayed by the traffic signals 12. It should be understood that Figure 1 is only showing a system for monitoring traffic flow in one direction along 35 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.

N:HLui&\XKeepSpci\TrRnso PR5925 Coavlet.doc 12/06/02 11 The system according to this embodiment of the invention is mounted on a pole 18 which may be an existing light pole, traffic signal pole, or especially installed pole.

The pole 18 mounts a wide angle camera 20 which can monitor the entire intersection of the roadways A and B as shown by the area 22 in Figure 1, and including at least one of the traffic signals 12 so that the image captured by the wide angle camera 20 includes the red light, amber light and green light associated with the traffic signals 12. 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 the traffic signal 12 is to determine 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 the traffic signals 12 need be in the field of view of the wide angled camera The pole 18 also mounts narrow angle or lane cameras 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 two lane cameras are provided. If more than two lanes are provided additional lane cameras 30 are utilised.

The cameras 20 and 30 are connected to a site computer which may also be mounted on the pole 18.

The cameras 30 therefore monitor part of the intersection which is monitored by the wide angle camera 20 and the parts monitored by the two cameras 30 are identified by the reference numerals 31 and 33. The cameras 20 and are preferably off the shelf digital 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 between 768 by 576 (approximately 0.5Mg Pixel) and a dynamic range of H:\Luisa\Keep\Speci\Transo1 PR5925 Cmpete.doc 12/06/02 12 and sustainable imaging speed of twenty five frames per second or better.

As shown in Figure 3 the cameras 30 (three shown in Figure 3) and the camera 20 are connected to the site computer for 40. The computer 40 includes a processing section which is powered by a power supply 52 which may be a battery, solar power supply or main supply if desired.

The processor 50 includes buffer memory 54 which stores images captured by each of the cameras 20 and 30 and a processing section 56 which determines when a traffic violation has occurred and identifies the images stored in the memory buffer 54 and transfers those images to hard disc 58 so that only the images associated with the violation are stored on the hard disc 58. The hard disc 58 is connected to a wireless communication link 60 so that the data relating to the images stored on the hard disc 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.

In the preferred embodiment of the invention the processor is equipped with sufficient buffer memory 54 for temporary storage of a sufficient number of images taken by both the wide angle camera 20 and the lane cameras 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). The wide angle camera 20 will capture images showing the violation, that is a vehicle moving through the intersection when the red light signal is displayed and the lane cameras 30 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 H:\Luisa\eep\Speci\Transol PR5925 Coplete.doc 12106/02 13 identified and the appropriate penalty notice issued.

In this embodiment the processing section 56 analyses the images taken by the camera 20 so that a change in the colour of the red light of the traffic signal 12 can be determined and therefore the commencement and end of the red light traffic phase of the signal 12 is determined.

The images are also processed so that if traffic movement through one of the lanes of the roadway as detected by the lane cameras 20 is determined during the period of the red light phase a traffic violation is captured. The images which are associated with that violation are then transferred from the memory buffers 54 to the hard disc 58 so that a sequence of images captured by the wide angle camera 20 showing the vehicle moving through the intersection and also one or more images captured by one of the lane cameras 30 which show the vehicle in close up are also captured. Those images are transmitted via the wireless communication link 60 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 recognising a licence plate of a vehicle, so that if a recognised licence 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 vehicle is present.

Since the invention enables relatively inexpensive cameras to be used and which can operate in effectively zero lux conditions, no supplementary lighting is required even at H:\Luisa\Keep\Speci\Transo PR5925 Cowlete doc 12/06/02 14 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.

Figure 4 is a flow chart illustrating initial calibration or set up of the system of Figure 1. The system of Figure 1 is set up via a graphical user interface operating on a laptop that can be connected to the computer 40. The software will allow the operator to take test shots using the wide angle camera 20. 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 the signals 12 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 the stop line 14 on the image and will draw a series of lines to define each of the lanes of the roadway that are to be monitored.

Figure 5 is a flow chart explaining operation of the system of Figure 1. Each frame taken by the wide angle camera is examined by the processing software to identify the status of the traffic signal. The colour pixels in the area defined by the setup system to identify the position of each of the red, green and amber signal lights are analysed 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 the stop line 14. The lane in which the movement is detected will also be recorded.

In the event that a movement beyond the stop line 14 is detected during the red light traffic phase, the images taken by the wide angle camera 20 (both before the point H:\Luis&\Keep\Speci\Traso1 PR5925 Con1ete.doc 12/06/02 15 of detection and after the point of detection) will be retained and transferred from the buffer 54 to the hard disc 58. The images taken by the appropriate lane camera are also retained and stored in the same manner. The images of the wide angle camera and the lane cameras pertaining to the one event will be linked by a suitable identification code and additional information including the 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 the communication link 60 to processing centre where the images can be decrypted and viewed for adjudication, verification, tamper validation and traffic penalty notice issuance.

Figure 2 shows the system used for detecting speed violations. In this embodiment a region of a roadway C is monitored by wide angle camera 20 and each of the appropriate lane ways of the road C are monitored by lane cameras 30. As in the earlier embodiment the cameras and 30 are connected to site computer 40. The regions monitored by the cameras 20 and 30 are shown by the reference numbers 81 insofar as the camera 20 is concerned and the reference numbers 82 and 83 insofar as the cameras are concerned.

Initial set up in this embodiment is the same as that described with reference to Figure 4 except that obviously the traffic signals 12 are not identified and the regions which are identified are the regions of the roadway monitored by the camera 20 and the specific lanes monitored by the cameras 30. Images are captured in the same way as described with reference to Figure 1 and the determination for a speed event is made by an external speed measuring device such as Doppler radar or laser H:\Lisa\Keep\SpeCi\Transo1 PR5925 Corpletedoc 12/06/02 16 speed measuring device. The lane in which the vehicle is travelling is determined in the same manner as described with reference to Figures 1 and 3 to 5. 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 cameras 30 (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 the link 58 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 the cameras and 30 in both of the embodiments described above and are stored in temporary buffer memory 54, it is not necessary to provide a 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 the hard disc 58 for transmission to the central facility.

Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

H:\Luisa\Kee\Speci\Transo1 PR5925 Coaplete.doc 12/06/02

Claims (14)

1. A red light traffic violation recording and processing system, comprising: at least one camera for monitoring a region under surveillance; means for supplying time, date and location data to provide an indication of the time, date and location of a violation; a storing means for continuously storing 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 in a violation period; 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; and processing means for processing images captured by a camera to identify changes in the colour of the traffic signals to thereby make a determination of the 25 commencement and end of a red light traffic phase and therefore define the violation period.

2. The system of claim 1 wherein the non-intrusive violation detection means is comprised by processing means which is for processing images captured by at least one camera so that by comparing images a change in image can identify vehicle presence and movement in the region and oooo therefore the occurrence of a violation. oooo 35

3. The system of claim 1 wherein the storing means includes a temporary storage means for temporarily continuously storing images taken by the at least one H:\Luioa\Keep\Speci\Transol PR5925 Cmplete.doc 16/10/06 18 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.

4. The system of claim 1 wherein the at least one camera and said a camera comprise a single wide angle camera for capturing an image 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, and also for capturing images of the region under surveillance.

The system of claim 4 wherein the at least one camera further comprises a plurality of narrow angled cameras for monitoring respective parts of the region.

6. The system of claim 5 wherein each narrow angled camera monitors a defined section of a lane of the roadway.

7. The system of claim 5 wherein the narrow angled 25 cameras are for providing a multiple-image set of the vehicle so that the number plate of the vehicle can be identified to thereby identify the vehicle associated with °o."the violation. 0.0

8. A method of detecting a red light traffic violation, comprising the steps of: monitoring a region of a roadway with at least one camera; monitoring vehicle presence and movement through 0000 35 the region using a non-intrusive vehicle detection means; :0.0 continuously storing images taken by the at least one camera in a storage means; 0 6 H:\LuiSa1\Kee\Speci\Traneo1 PR5925 Complete.doc 16/10/06 19 processing images captured by a camera to identify changes in the colour of the traffic signals to thereby make a determination of the commencement and end of a red light traffic phase and therefore define the violation period; detecting a traffic violation in the region under surveillance during the violation period; determining images stored by the storage means and which relate to the traffic violation so that those images can be used as evidence of the violation and also to identify the vehicle associated with the violation; and providing time, date and location data to provide the time, date and location of the violation.

9. The method of claim 8 wherein the presence of a vehicle in the region is detected by a radar or laser.

The method of claim 8 wherein the at least one camera comprises a wide angle camera and at least one narrow angle camera, and the method further comprises temporarily storing images taken by the wide angle camera and at least one narrow angle camera and then subsequently storing images from the temporarily stored images associated with the violation so that the images can be 25 communicated for subsequent processing to provide the :0o940 evidence of the violation and also the vehicle. .0

11. The method of claim 10 wherein the wide angle camera captures the image of the traffic signal so that the red ooo: traffic signal can be identified to make the determination of the commencement and end of the red light traffic phase o and therefore the violation period. eeo. S

012. The method of claim 8 wherein a plurality of 35 narrow angled cameras are utilised for monitoring respective parts of the region so that all parts of the region are monitored by the plurality of narrow angled H,\Lisal\Keep\Speci\Transo1 PR5925 Complete.doc 16/10/06 20 cameras.

13. The method of claim 12 wherein each narrow angled camera monitors a section of the lane of the roadway.

14. The method of claim 12 wherein 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. Dated this 17th day of October 2006 TRANSOL PTY LTD By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia o* .o o *oo H \Luisa1\Keep\Speci\Trango1 PR5925 Conglete.doc 16/10/06