* NOTICE*
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`JPO and INPIT are not responsible for any damages caused bythe useofthis translation.
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`1. This document has been translated by computer. So the translation may notreflect the original precisely.
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`2.“ shows a word which cannotbetranslated.
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`3.
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`In the drawings, any words are nottranslated.
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`Patent Number
`
`JP2004102545A
`
`Bibliography
`
`(19) [Publication country] JP
`
`(12) [Kind of official gazette] A
`
`(11) [Publication number] 2004102545
`
`(43) [Date of publication of application] 20040402
`
`(54)
`
`[Title of the invention] TRAFFIC SITUATION DISPLAYING METHOD AND
`
`TRAFFIC SITUATION DISPLAYING DEVICE
`
`(51) [International Patent Classification 7th Edition]
`GO8G 1/01
`GO6T 1/00
`GO6T 11/60
`G08B 25/00
`
`GO8G 1/04
`
`[Fl]
`
`GO8G
`
`1/01
`
`GO6T
`
`1/00
`
`330A
`
`GO6T 11/60
`
`120A
`
`GO8B 25/00
`
`510M
`
`GO8G
`
`1/04
`
`E
`
`D
`
`(21) [Application number] 2002262069
`
`(22) [Filing date] 20020906
`
`(71) [Applicant]
`
`[Name] SUMITOMO ELECTRIC IND LTD
`
`(72) [Inventor]
`
`[Full name] KAWASAKI KIICHI
`
`[Full name] NISHIYAMA KAZUTO
`
`Abstract
`
`(57) [Overview]
`
`PROBLEM TO BE SOLVED: To provide a method and device for displaying the traffic
`
`

`

`situation which visually display the information on the traffic situation.
`
`SOLUTION: A vehicle is extracted for each unit division (for each photographed image)
`
`by taking the difference from the backdrop image (S11), and the rate of space
`
`occupation and the spatial mean speed (spatial parameter) in the applicable division are
`
`calculated (S12), and the number of vehicles and the vehicle speed are calculated from
`
`the rate of space occupation and the spatial mean speed, respectively, (S13 and $14).
`
`In case the micro-animation indication is to be made, the simulated vehicle image is
`
`displayed together with the backdrop image in accordance with the obtained number of
`
`vehicles and the vehicle speed, and in case the general outlook indication is to be made,
`
`the wide-area outlook image to show the traffic situation over a wide area is displayed.
`
`Claim
`
`[Patent Claims]
`
`[Claim 1]
`
`In the traffic situation display method, an image processing is performed using a
`
`photographed image obtained by photographing a road by 1 or more photographing
`
`means, and traffic situation information obtained by the image processing is displayed.
`
`A traffic condition display method, comprising : calculating a space parameter for each
`
`predetermined section of a road on the basis of the captured image ; generating a road
`
`condition image corresponding to eachof the sections ; and determining a display color
`
`of the generated road condition image based on the calculated space parameter, and
`
`displaying the road condition image with a predetermined display color.
`
`[Claim 2]
`
`The method of claim 1, wherein the spatial parameter includes a space occupancy and
`
`a spatial average velocity of a vehicle included in the captured image.
`
`[Claim 3]
`
`The traffic situation display device performs an image processing using a photographed
`
`image obtained by photographing a road by 1 or more photographing means and
`
`displaystraffic situation information obtained by the image processing.
`
`Means for calculating a spatial parameter for each predetermined section of the road
`
`based on the photographed image ; A traffic situation display device comprising : means
`
`for generating a road condition image corresponding to each section ; means for
`
`determining a display color of the generated road condition image based on the
`
`calculated space parameter ; and means for displaying the road condition image with a
`
`display color determined by the means.
`
`[Claim 4]
`
`

`

`The traffic situation display device according to claim 3, further comprising : means for
`
`generating 1 or more simulated vehicle images based on the calculated space
`
`parameter ; means for generating a background image based on the captured image ;
`
`and means for overwriting the generated simulated vehicle image on the background
`
`image.
`
`[Claim 5]
`
`The traffic situation display device according to claim 4, further comprising means for
`
`determining a display color of the simulated vehicle image according to the spatial
`
`parameter.
`
`[Claim 6]
`
`The traffic situation display device according to claim 4 or 5, further comprising : means
`
`for detecting a specific driving state of a vehicle included in the captured image ; and
`
`means for displaying a simulated vehicle image corresponding to the vehicle in the
`
`traveling state with a predetermined display color when the traveling state is detected.
`
`[Claim 7]
`
`The traffic situation display device according to any one of claims 4 to 6, further
`
`comprising a means for switching between display of the road condition image and
`
`display of the simulated vehicle image and the background image.
`
`[Claim 8]
`
`The traffic situation display device according to any one of claims 3 to 7, wherein the
`
`space parameter includes a space occupation ratio and a space average speed of a
`
`vehicle included in the captured image.
`
`[Claim 9]
`
`The traffic situation display device according to claim 8, wherein, instead of the space
`
`occupation ratio, the traffic density of the vehicle in the interval and the travel time of the
`
`vehicle in the interval are used instead of the space average speed.
`
`[Claim 10]
`
`The traffic situation display device according to any one of claims 3 to 9, further
`
`comprising means for transmitting the road condition image, the simulated vehicle image,
`
`and the background image to the outside.
`
`Description
`
`[Detailed description of the invention]
`
`[0001]
`
`[Technical field of invention]
`
`The present invention relates to a traffic situation display method andatraffic situation
`
`

`

`display devicefor displaying traffic situation information obtained by processing an image
`
`of a road.
`
`[0002]
`
`[Prior art]
`
`A photographing device such as a video camerais installed on an expressway and a
`
`general road for the purpose of monitoring a traffic situation such as occurrence of
`
`congestion and occurrence of an accident. In particular, a large number of photographing
`
`devices are installed in a long tunnel so that a dead angle cannot be formed. Images
`
`obtained by these photographing devices (captured images) are transmitted to a control
`
`center which managesroads, and image processing is executed by an image processing
`
`device to determine a congestion level and detect an accident (for example, refer to
`
`Patent document 1). When occurrence of congestion, occurrence of an accident, and
`
`the like occur, information indicating the occurrence of the congestion is reported from
`
`the road manager to the driver.
`
`[0003]
`
`[Patent document 1]
`JP 2001 -93079A
`
`[0004]
`
`[Problem to be solved by the invention]
`
`However,
`
`the conventional
`
`information provision only reports the occurrence of
`
`congestion at a predetermined point, and the provision of a wider traffic situation is
`
`desired from the user(driver).
`
`[0005]
`
`In addition, in case of determining congestion using several threshold values, congestion
`
`is determined only in several stages, and therefore, even if it is determined that the traffic
`
`jam is non-congested, there is a problem that congestion is actually progressing, and
`
`accurate information cannot be transmitted. Further, since the concept of traffic
`
`congestion differs from one driver to another, it is desired to provide information that can
`
`subjectively determine whether or not there is a congestion.
`
`[0006]
`
`Further,
`
`the traffic situation information provided by the road manager is roughly
`
`information such asthe level of congestion, the length of the traffic congestion, and the
`
`time required to the main point, which is expressed in a stepwise manner, and it
`
`is
`
`desired to develop a device capable of visually providing the user with a detailed traffic
`situation of the entire road.
`
`

`

`[0007]
`
`The present invention has been made in view of such circumstances, and provides a
`
`configuration in which a space parameter is calculated for each predetermined section
`
`of a road, and a road situation image is displayed by a display color determined based
`
`on the space parameter. To provideatraffic situation display method andatraffic
`
`situation display device capable of visually providing a wide range oftraffic conditions in
`more detail.
`
`[0008]
`
`It is another object of the present invention to provide a traffic situation display device
`
`which can be configured to generate 1 or more simulated vehicle images based on the
`
`calculated spatial parameters and to display the generated simulated vehicle images
`
`together with the background image, thereby visually and intuitively reporting the detailed
`situation of the road.
`
`[0009]
`
`[Means for solving the problem]
`
`A traffic situation display method according to a 1 aspect of the present invention is
`
`characterizedin that the image processing is performed using a captured image obtained
`
`by photographing a road by 1 or more photographing means, and the traffic situation
`
`information obtained by the image processing is displayed. A space parameter is
`
`calculated for each predetermined section of a road on the basis of the photographed
`
`image, a road condition image corresponding to each section is generated, a display
`
`color of the generated road condition image is determined based on the calculated space
`
`parameter, and the road condition image is displayed by a specified display color.
`
`[0010]
`
`In the 1 aspect of the present invention, the space parameter is calculated for each
`
`predetermined section of the road, and the road condition image is displayed by the
`
`display color determined based on the calculated space parameter. For example, unlike
`
`the conventional traffic situation display based on congestion determination, it is possible
`
`to display a detailed situation of an entire road in multiple stages in multiple stages and
`
`to provide visual and intuitive traffic situation information. Further, since the user
`
`including the road manager and the general driver is not presented with the result of the
`
`congestion determination, each user can grasp the traffic situation according to each
`
`idea ofthe traffic flow such as the congestion.
`
`[0011]
`
`In the traffic-situation-displaying method concerning the 1st
`
`invention,
`
`the traffic-
`
`situation-displaying method concerning the 2nd invention is the aforementioned empty.
`
`

`

`The parameter includes a space occupation ratio and a space average speedof a vehicle
`
`included in the photographed image.
`
`[0012]
`
`According to the 2 aspect of the present invention, since space occupancy and space
`
`average velocity are included as spatial parameters,
`
`it becomes possible to visually
`
`display the traffic flow determined by the correlation.
`
`[0013]
`
`A traffic situation display device according to a 3 aspect of the present invention is a
`
`traffic situation display device for performing an image processing using a captured
`
`image obtained by photographing a road by 1 or more photographing means and
`
`displaying traffic situation information obtained by image processing, wherein a space
`
`parameter is calculated for each predetermined section of a road based on the captured
`
`image. A means for generating a road condition image corresponding to each section, a
`
`means for determining a display color of the generated road condition image on the basis
`
`of the calculated space parameter, and a means for displaying the road condition image
`
`with a display color determined by the means are provided.
`
`[0014]
`
`In the 3 aspect of the present invention, the space parameter is calculated for each
`
`predetermined section of the road, and the road condition image is displayed by the
`
`display color determined based on the calculated space parameter. For example, unlike
`
`the conventional traffic situation display based on congestion determination, it is possible
`
`to display a detailed situation of an entire road in multiple stages in multiple stages and
`
`to provide visual and intuitive traffic situation information. Further, since the user
`
`including the road manager and the general driver is not presented with the result of the
`
`congestion determination, each user can grasp the traffic situation according to each
`
`idea ofthe traffic flow such as the congestion.
`
`[0015]
`
`A traffic situation display device according to a 4 aspect of the present invention is the
`
`traffic situation display device according to the 3 aspect of the present
`
`invention.
`
`According to an aspect of the present invention, there is provided a device for generating
`
`a 1 or more simulated vehicle images based on a calculated spatial parameter, a means
`
`for generating a background image based on the captured image, and a means for
`
`overwriting the generated simulated vehicle image on the background image.
`
`[0016]
`
`According to the 4 aspect of the present invention, since the simulated vehicle image is
`
`

`

`generated based on the spatial parameter and displayed together with the background
`
`image, it is possible to provide the user with information that can visually and intuitively
`
`grasp the detailed situation of the entire road unlike the information of the rough traffic
`
`situation such as the congestion degree of several stages. Further, by presenting
`
`detailed information, the user can determine whether or not the user is congested due to
`his / her own idea.
`
`[0017]
`
`A traffic situation display device according to a 5 aspect of the present invention is the
`
`traffic situation display device according to the 4 aspect, further comprising a means for
`
`determining a display color of the simulated vehicle image according to the spatial
`
`parameter.
`
`[0018]
`
`According to the 5 aspect of the present invention, since color is assigned to the
`
`simulated vehicle image according to the spatial parameter,it is possible to provide the
`
`user with information which can instantaneously grasp thetraffic situation by performing
`
`color coding according to the traveling speed of each vehicle.
`
`[0019]
`
`A traffic situation display device according to a 6 aspect of the present invention is the
`
`traffic situation display device according to the 4 or 5 aspect of the present invention,
`
`further comprising : means for detecting a particular driving state of a vehicle included in
`
`the captured image ; and means for displaying a simulated vehicle image corresponding
`
`to the vehicle in the traveling state in a predetermined display color when the traveling
`state is detected.
`
`[0020]
`
`In the 6 aspect of the present invention, when the specific driving state is detected, the
`
`simulated vehicle image is displayed with a predetermined display color. For example,
`
`by displaying a simulated vehicle image corresponding to an abnormal traveling vehicle
`
`subjected to sudden stop, sudden deceleration, or the like, and a dangerous traveling
`
`vehicle running in a state in which the speed limit is ignored, with a predetermined display
`
`color, a vehicle to be viewed can be made conspicuous, and, for example, attention can
`
`be aroused to a user.
`
`[0021]
`
`A traffic situation display device according to a 7 aspect of the present invention is the
`
`traffic situation display device according to any of the 4 to 6 aspects, further comprising
`
`a means for switching the display of the road situation image and the display of the
`
`

`

`simulated vehicle image and the background image.
`
`[0022]
`
`According to the 7 aspect of the present invention, since a means for switching between
`
`the display of the road condition image and the display of the simulated vehicle image
`
`and the background image is provided, it is possible to switch and display the general
`
`traffic condition and the detailed traffic condition of the specific range.
`
`[0023]
`
`A traffic situation display device according to a 8 aspect of the present invention is the
`
`traffic situation display device according to any one of the 3 to 7 aspects, wherein the
`
`spatial parameter includes a space occupation ratio and a space average speed of a
`
`vehicle included in the captured image.
`
`[0024]
`
`According to the 8 aspect of the present invention, since space occupancy and space
`
`average velocity are included as spatial parameters,
`
`it becomes possible to visually
`
`display the traffic flow determined by the correlation.
`
`[0025]
`
`A traffic situation display device according to a 9 aspect of the present invention is the
`
`traffic situation display device according to the 8 aspect of the present invention, wherein
`
`the traffic density of the vehicle in the interval and the running time of the vehicle in the
`
`interval are used instead of the space occupancyratio in place of the space occupancy
`ratio.
`
`[0026]
`
`According to the 9 aspect of the present invention, since the traffic density and the
`
`traveling speed of the vehicle are used instead of the spatial parameters, it is possible to
`
`visually display the traffic flow determined by the correlation.
`
`[0027]
`
`A traffic situation display device according to a 10 aspect of the present invention is the
`
`traffic situation display device according to any one of the 3 to 9 aspects, further
`
`comprising means for transmitting the road condition image, the simulated vehicle image,
`
`and the background image to the outside.
`
`[0028]
`
`According to the 10 aspect of the present invention, since the road status image, the
`
`simulated vehicle image, and the background image are transmitted to the outside, for
`
`example, when the vehicle is equipped with a display unit capable of displaying an image
`
`received by the in-vehicle communication device and the in-vehicle communication
`
`device, it is possible to visually provide the traffic situation to not only the road manager
`
`

`

`but also the driver.
`
`[0029]
`
`[Embodimentof invention]
`
`Hereinafter, the present invention will be described in detail with reference to the
`
`accompanying drawings.
`
`FIG. 1
`
`is a schematic diagram illustrating a configuration of a traffic situation monitoring
`
`system using the traffic situation display device of the present invention.
`
`In FIG. 1,
`
`reference numeral 6 denotes a vehicle whichis traveling on a road 5, photographs a
`
`vehicle 6 running by the photographing devices7,7,. installed at intervals along the road
`
`5, and transmits the photographed images obtained by the respective photographing
`
`devices 7,7,. to the image processing device 10 at any time. Image processing device
`
`10 performs an image processing on the captured image transmitted from each of
`
`imaging devices 7,7,,. to generate image data representing a traffic situation, and outputs
`
`the generated image data to monitor 21 of control center 20. In the same wayasin the
`
`case of the imaging apparatus 7, the vehicle is transmitted to the outside through the
`
`roadside antennas 8,8,. installed at appropriate intervals along the road 5.
`
`[0030]
`
`The imaging device 7 is, for example, a CCTV camera (CCTV : Closed / Circuit
`
`Television), and a CCD (Charge Coupled Device), a CMOS (Complementary Metal
`
`OxideSemiconducton), or the like is used for the imaging device. The photographing
`
`device 7 is provided at an appropriate installation interval (e.g., 100 m) in the traveling
`
`direction of the vehicle 6 or in the opposite direction, and in order to allow the road 5 to
`
`be viewed far, for example, an upper portion of a support column or the like provided
`
`upright on a central separation band or a roadside band, or a ceiling or a * in a tunnel is
`
`installed on a wall surface near the ceiling. *
`
`In addition, the imaging device 7 is configured to capture the front or rear of the vehicle
`
`6 in a bird's eye view.
`
`[0031]
`
`The image processing apparatus 10 includes a camera port for connecting the respective
`
`imaging devices 7,7,,. (see FIG. 5), and performs an image processing on each captured
`
`image input through the camera port.
`
`In the image processing, a space parameter is
`
`calculated from each captured image, and a micro animation image or a wide area
`
`general situation image to be described later is generated based on the calculated space
`
`parameter.
`
`Here, the space parameter includes a space occupation ratio and a space average
`
`

`

`speed. The space occupation ratio is a value obtained by dividing the total length of all
`
`the vehicles existing in the calculation range at an imaging timing by the total range
`
`length, and the spatial average speed is a value obtained by measuring the
`
`instantaneous speed of each vehicle existing within the calculation range at a certain
`
`imaging timing and arithmetically averaging the measurement values.
`
`[0032]
`
`In generating a microanimation image, a background image is generated as viewed from
`
`above, and a simulated vehicle image simulating a vehicle is generated based on the
`
`space parameter. The generated simulated vehicle image is overwritten on the
`
`background image. At this time, by controlling the display position of the simulated
`
`vehicle image with respect to the background image at a constant period (frame span)
`
`such that the display position of the simulated vehicle image is shifted by an amount
`
`proportional to the vehicle speed, it is possible to give a motion to the simulated vehicle
`
`image and display it. Note that the simulated generation image and the background
`
`image to be displayed may be an actual image obtained by changing the viewpoint of
`
`the captured image, or may be a schematic image generated inside the image
`
`processing apparatus 10.
`
`[0033]
`
`In generating a wide area overview image, an image indicating a wide area traffic
`
`situation that is not displayed in a micro animation image is generated. In the wide area
`
`general situation image, a predetermined section of a road (for example, every 100 m)
`
`and a section are divided per lane, and the display color is changed by the average
`
`speed of the vehicle included in each section to display the traffic situation.
`
`[0034]
`
`A monitor 21 installed in the control center 20 is a display means for displaying an image
`
`generated by the image processing apparatus 10, and specifically,
`
`is a CRT, a liquid
`
`crystal display, or the like.
`
`[0035]
`
`Further, the image processing apparatus 10 transmits the generated image as traffic
`
`situation information to the monitor 21 and transmits the generated image to the outside
`
`via the roadside antennas 8,8,. Therefore, when the vehicle 6 includes an in-vehicle
`
`communication device capable of communicating with the roadside antenna 8 and a
`
`display device for displaying image data received by the in-vehicle communication device,
`
`it is possible to confirm the traffic situation information even in the vehicle 6 and to provide
`
`information to not only the road manager but also the general driver.
`
`[0036]
`
`

`

`Inthis embodiment, as shownin FIG. 1, the * image processing apparatus 10 is installed
`
`outside the control center 20, but the image processing apparatus 10 may beinstalled
`
`inside the control center 20.
`
`In addition,
`
`in this embodiment,
`
`the traffic situation
`
`information is transmitted to the in-vehicle communication device mounted on the vehicle
`
`6 using the roadside antenna 8. It is needless to say that the present invention may be
`
`applied to a driver using a data communication system used in a mobile phone or the
`
`like, or to an FM multiplex broadcast system using an FM multiplex broadcast system.
`
`[0037]
`
`FIG. 2 is a schematic diagram showing an example of a captured image taken by the
`
`imaging apparatus 7. As described above, since the photographing apparatus 7 is
`
`installed at a position where the road 5 can be viewedto a far distance and the front or
`
`rear side of the vehicle 6 is photographed, a photographed image at a certain
`
`photographing timing becomes an image as shownin FIG. 2. The captured image 40
`
`shown in FIG. 2 includes a background image 45including a road and 2 vehicle images
`
`46 a and 46 b. When the captured image 40is input, the image processing apparatus 10
`
`can satisfactorily extract the vehicle images 46 a and 46 b from the background image
`
`45 by taking a difference from an image of only a background generated in advance.
`
`[0038]
`
`FIG. 3 is a schematic diagram illustrating a type of an image generated by the image
`
`processing apparatus 10. A plurality of *
`
`The captured images 40,40,. obtained by the shadow devices 7,7,. are, for example, an
`
`image as shownin an upper portion of FIG. 3, and a spatial parameter is calculated
`
`based on the captured images 40,40. Aswill be described later, the number of vehicles
`
`included in the captured image 40 is calculated in a simulated manner from the space
`
`occupancythat is one of the spatial parameters, and the vehicle speed is calculated ina
`
`simulated manner from the spatial average speed.
`
`[0039]
`
`According to the present
`
`invention, a micro animation image is generated using a
`
`simulated vehicle image generated based on the calculated number of vehicles and the
`
`vehicle speed. That is, as shown in the middle of FIG. 3, a microanimation image 50
`
`including the background image 55 of the road and the simulated vehicle images 56 a to
`
`56 d is generated. Here, the simulated vehicle images 56 a to 56 d are rectangular
`
`images simulating the vehicle and are moved and displayed on the background image
`
`55 at a speed corresponding to the vehicle speed. Further, the simulated vehicle images
`
`56 a to 56 d are displayed in a display color determined according to the vehicle speed,
`
`

`

`so that the user can instantly grasp the traffic situation.
`
`[0040]
`
`In addition, in the present invention, in order to provide a wider traffic situation for a user,
`
`a wide area general image 60 as shownin the lowerpart of FIG. 3 is generated. Each of
`
`the section images 61 a to 61 represented by a rectangular region presents a traffic
`
`situation with a color attached thereto. For example, a color (e€.g.,
`
`red) assigned to the
`
`section image 61 a indicates a state in whichtraffic flow is congested, and represents a
`
`state in which the possibility of traffic congestion is very high. Further, a color (for
`
`example, green or blue) assigned to the section image 61 indicates a state in which a
`
`traffic flow is smooth, and indicates a state in which a possibility of a traffic jam is low
`
`and a vehicle can run smoothly.
`
`[0041]
`
`FIG. 4 is a schematic diagram showing an example of an image displayed on the monitor
`
`21.
`
`In the monitor 21, 2 types of display modes can be selected corresponding to an
`
`image generated by the image processing apparatus 10. FIG. 4 a shows a case where
`
`a micro animation display mode for displaying the micro animation image is selected,
`
`and a simulated vehicle image which is color-coded in accordance with the vehicle speed
`
`at another stage is displayed together with a background image such as a road. FIG. 4
`
`(b) shows a casein which the general situation display mode for displaying the wide area
`
`overview image is selected, and a rectangular image in whichthe traffic situation for each
`
`section is represented by the display color is displayed.
`
`[0042]
`
`Display switching buttons 21 a for switching the display mode and scroll buttons 21 b
`
`and 21 c for scrolling the display range are displayed in the respective display areas.
`
`The display switching button 21 a and the scroll buttons 21 b and 21 c can be selected
`
`by a pointer controlled by an input device such as a mouse, a cursor key, or the like,
`
`which is not shown in the drawing, and when the display switching button 21 a is selected,
`
`the display content can be switched from one display mode to the other display mode.
`
`In addition, when the scroll buttons 21 b and 21 c are selected, the display range can be
`
`movedin the direction of the white arrow indicated by the scroll buttons 21 b and 21 c.
`
`[0043]
`
`FIG. 5 is a block diagram illustrating an internal configuration of the image processing
`
`apparatus 10. The image processing apparatus 10 includes a CPU 11, and a
`
`ROM13,RAM14, a communication port 15, an image processing ASIC 16, a frame
`
`memory 17, a plurality of camera ports 18,18,. are connected to the CPU 11 via a bus
`12.
`
`

`

`[0044]
`
`Inthe ROM 13, a control program for controlling the hardware described aboveis stored,
`
`and the CPU 11 develops the control program on the RAM 14 as necessary and controls
`
`the hardware. Further, the RAM 14 temporarily stores various data generated during
`
`execution of the control program. The data temporarily stored in the RAM 14 is, for
`
`example, data of a simulated vehicle image generated based on a spatial parameter.
`
`[0045]
`
`The camera port 18,18.
`
`is a connection connector for connecting the photographing
`
`devices 7,7,
`
`An AD converter which converts an image signal
`
`inputted through the connection
`
`connector from an analog signal into a digital signal is provided.
`
`The frame memory 17 temporarily stores the digital converted video signal as image data.
`
`The image data to be stored is a set of pixels having an RGB value for each coordinate
`
`point of the x-axis and y-axis, and the RGB value ofthe pixel is, for example, 8 bits of
`
`256 gradations. In addition, it is not necessary to use color data as the image data, and
`
`it is possible to use a luminance value (e.g., 256 gradations) defined for each coordinate
`
`point of the x-axis and the y-axis.
`
`The image processing ASIC 16 is an IC that executes image processing of image data
`
`stored in the frame memory 17 according to an instruction from the CPU 11.
`
`A monitor 21 installed in the control center 20 and roadside antennas 8,8,. installed on
`
`the road 5 are connected to the communication port 15, and image data subjected to
`
`image processing is transmitted to the communication port.
`
`[0046]
`
`FIG. 6 is a flowchart illustrating a process procedureof the image processing apparatus
`
`10. First, the CPU 11 of the image processing apparatus 10 performs aninitialization
`
`process (Step S 1).
`
`In the initialization processing, a background image is generated
`
`which is necessary when extracting a vehicle image from a captured image obtained by
`
`the photographing apparatus 7. Note that the background image may be changed
`
`according to a time zone or weather. Further,it is not necessarily necessary to generate
`
`a background image every time an initialization process is performed, and the generated
`
`background image may be stored in the RAM 14 and the stored background image may
`
`be read in the initialization process.
`
`[0047]
`
`Next, the image processing apparatus 10 starts an image input (Step S 2), converts the
`
`video signal from each of the photographing apparatuses 7,7,. into a digital signal, and
`
`

`

`sequentially stores the digital signal in the frame memory 17 as the image data.
`
`[0048]
`
`Next, the CPU 11 of the image processing apparatus 10 gives an instruction to the image
`
`processing ASIC 16 and performs an image data generation process to be described
`
`later (Step S 3). In the image data generation process, a space parameter is calculated
`
`for each unit interval (each shot image), and image data corresponding to the selected
`
`display mode is generated. Note that the image data generation process will be
`described in detail later.
`
`[0049]
`
`Next, the CPU 11 gives an instruction to the image processing ASIC 16, and sequentially
`
`generates composite image data by continuing the image data for each unit section
`
`generated in Step S 3 (Step S 4). Then, the generated composite image data is output
`
`(Step S 5).
`
`[0050]
`
`FIG. 7 is a flowchart showing a processing procedure of the image data generation
`
`process.First, the image processing ASIC 16 extracts a vehicle for each unit interval (for
`
`each captured image) (Step S 11). Extraction of the vehicle is performed by taking a
`
`difference between the background image obtained by an initialization process (see FIG.
`
`6) and the captured image. Then, the spatial parameter of the corresponding section is
`
`calculated (Step S 12). The calculated spatial parameter is stored in the RAM 14 in
`
`association with the captured image.
`
`[0051]
`
`Next, the CPU 11 reads the space occupancyrate and the space average velocity from
`
`the space parameter stored in the RAM 14, calculates the number of vehicles based on
`
`the read space occupancyrate (Step S 13), and calculates the vehicle speed based on
`
`the space average velocity (Step S 14). The calculated vehicle algebra and vehicle
`
`speed are stored in RAM 14.
`
`[0052]
`
`Here, the number of vehicles can be obtained by the following method. The numberof x
`
`stand and large-size cars (it is considered as 10 m of vehicle length) for the number of
`
`the small-size cars (it is considered as 5 m of vehicle length) which should be computed
`
`Namely, y stand, When section length is set to Lm, it is possible to compute the number
`
`of vehicles by asking for ** of x and y so that it may become equal as muchas possible
`
`at the space share whichthe value of (5xx+10xy) x100-/L read. In this case, a ratio of x
`