JPH09305891A - Vehicle monitoring device - Google Patents

Abstract

(57) A vehicle monitoring device for transmitting, to a control center, traffic condition information obtained by image-processing a captured image of a camera and image data of the captured image itself at low cost. SOLUTION: A CCD camera 1 installed near a road photographs a road, and by image processing of the photographed image, vehicle detection, vehicle type detection, parking detection, abnormal traffic (accident) detection, and congestion length measurement are performed. The captured image itself or the difference image obtained by pre-processing the captured image and the edge image are subjected to compression processing, and the detection / measurement result and the compressed image data are transmitted to the control center 40 using the same line 50. At this time, the compression condition is instructed from the control center 40 side or determined by the monitoring device body 30 side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a traffic state of a vehicle by photographing a vehicle passing on a road with a camera, and processing the photographed image, and centralizes the detection result and the image data of the vehicle. The present invention relates to a vehicle monitoring device that transmits to a control center.

[0002]

2. Description of the Related Art In recent years, due to the rapid increase in the number of vehicles, congestion has frequently occurred not only in large cities but also in small and medium-sized cities, and a traffic control system for managing and controlling these many vehicles. The importance of is increasing more and more, and sophistication of the system is desired.

In order to make road traffic smooth, a system is widely used in which ultrasonic sensors arranged at predetermined intervals above the road detect the presence of a vehicle and the speed of the vehicle to detect the traffic state of the vehicle. Has been converted. However, since the information collected by this method is limited to the traffic volume and the occupancy rate, the collected information is insufficient for the sophistication of the traffic control system.

Therefore, in order to realize the sophistication of the traffic control system, it has been developed to collect various kinds of information on the traffic condition by a technique using an ITV (industrial television) camera based on image processing technology. There is. For details of this type of vehicle monitoring device, see March 1994, Sumitomo Electric No. 144, p. (115) -p. (118). According to this document, for example, the ITV above the intersection
A camera is installed and the ITV camera takes pictures of roads with multiple lanes. Then, by processing the photographed image, not only vehicle detection, speed measurement, vehicle type discrimination, and parking detection are performed, but also abnormality in traffic flow associated with a stopped vehicle due to an accident, failure, or the like is detected.

[0005] As a prior art related to the present invention,
There is a "traffic monitoring system" disclosed in JP-B-60-49360 and a "traffic flow monitoring device" disclosed in JP-A-63-24499. The former "traffic monitoring system" relates to an automatic speed control device, which uses an ITV camera and a speed measurement device to display a high-quality image in the case of a speeding vehicle and a high-quality image in the case of a vehicle that does not violate. Transmits low-quality images to the control center. The latter "traffic flow monitoring device" links the shooting timing of the ITV camera with a traffic light, and captures a group of stopped vehicles as a still image with the ITV camera via a line dedicated to the camera. The still image data is transmitted to the control center.

[0006]

[Problems to be Solved by the Invention] With the vehicle monitoring device shown in March 1994, Sumitomo Electric No. 144, various information on traffic conditions can be quickly acquired based on captured images. Although it is useful for sophistication, it only transmits the detection and measurement results to the control center, not the image data. Therefore, even if it is possible to detect that a traffic jam or an abnormal state has occurred, the precise cause cannot be visually recognized on the control center side, and the best countermeasure cannot be taken.

In the "traffic monitoring system" disclosed in Japanese Patent Publication No. 60-49360 and the "traffic flow monitoring device" disclosed in Japanese Patent Application Laid-Open No. 63-24499, image data captured by an ITV camera is displayed on a monitor TV. To the control center equipped with. However, since the amount of data to be transmitted is large, the cost of the transmission line becomes high. This extends the system to I
This causes a rise in the cost of adding a TV camera and the operating cost of the transmission line. Further, when the amount of data to be transmitted is large, it takes a long time to perform the transmission processing, which makes it difficult to handle in real time. Further, since only the image directly taken by the ITV camera is transmitted, the accurate traffic condition cannot always be recognized only by the image information, and as a result, even in these systems, the abnormal condition can be detected. There is a problem that the best measures cannot always be taken.

The present invention has been made in view of such circumstances, and it is possible to reduce the amount of image data to be transmitted by temporarily compressing an image obtained by a camera and transmitting the compressed image data. An object of the present invention is to provide a vehicle monitoring device that shortens time and enables real-time response.

Another object of the present invention is to transmit the compressed image data through the line for transmitting the detection / measurement results, thereby eliminating the need to provide a dedicated line for transmitting the image data, which results in a special cost increase. It is to provide a vehicle monitoring device that does not cause

Still another object of the present invention is to provide a vehicle monitoring device capable of transmitting compressed image data to a control center faster by transmitting only compressed image data that is at least necessary for visual recognition of traffic conditions. It is in.

Still another object of the present invention is to allow the control center to arbitrarily adjust the compression rate in the compression process so that image data of a desired compression rate can be transmitted, and a high quality image can be transmitted at the control center. An object of the present invention is to provide a vehicle monitoring device capable of selecting a low quality image.

Still another object of the present invention is to reduce the compression rate when an abnormal traffic condition occurs so that the control center can recognize a high quality image, so that accurate information can be obtained in the abnormal traffic condition. It is to provide a vehicle monitoring device that can obtain the following.

[0013]

According to a first aspect of the present invention, there is provided a vehicle monitoring apparatus which photographs a passing vehicle with a camera, detects a traffic state based on the photographed image, and transmits the detection result to a control center. The monitoring device is provided with a compression unit for compressing an image of the vehicle and a transmission unit for transmitting the compressed image data and the detection result to the control center via the same line.

According to a second aspect of the present invention, there is provided a vehicle monitoring device for photographing a passing vehicle with a camera, detecting a traffic state based on the photographed image, and transmitting the detection result to a control center. Compression means for compressing the image,
A transmission means for transmitting the compressed image data and the detection result to the control center through the same line; and a setting means for setting a compression rate in the compression means in accordance with an instruction from the control center side. Characterize.

According to a third aspect of the present invention, there is provided a vehicle monitoring device which photographs a passing vehicle with a camera, detects a traffic state based on the photographed image, and transmits the detection result to a control center. Based on the result, a judging means for judging whether it is a normal traffic state or an abnormal traffic state, a compressing means for compressing the image of the vehicle, and a compression ratio in the compressing means for judging whether the abnormal traffic state is normal. It is characterized by further comprising setting means for setting the value lower than that in the case of traffic condition, and transmission means for transmitting the compressed image data and the detection result to the control center through the same line.

A vehicle monitoring device according to a fourth aspect is the third aspect.
In the above, the setting means is configured to set the compression rate to be lower for only the image of the area having the abnormal traffic state than in the case of the normal traffic state.

A vehicle monitoring device according to a fifth aspect is the third aspect.
In, in the case where a storage means for storing original image data by the camera or compressed compressed image data is stored, and the determination means determines an abnormal traffic condition, the compressed image data before determining the abnormal traffic condition is It is characterized in that it is configured to transmit to the control center.

A vehicle monitoring device according to a sixth aspect is the first aspect.
1 to 5, a first image creating circuit for creating a difference image between a captured image obtained by the camera and a reference image showing a road surface where no vehicle exists, a difference between two captured images obtained at different times Of the second image creating circuit that creates an image, the third image creating circuit that creates an edge image by differentiating a shot image, and the fourth image creating circuit that creates a partial image by extracting a part of the shot image At least one image forming circuit of the first, second, third and / or fourth
It is characterized in that the image created by the image creating circuit is compressed by the compression means.

A general vehicle monitoring device performs image processing on an image taken by an ITV camera to detect a vehicle, a vehicle type,
It detects parking and abnormal traffic, measures speed and congestion, and sends the results to the central control center. If not only the image taken by the ITV camera is used for such detection / measurement processing, but also the image data is transmitted to the control center,
You will be able to recognize the traffic condition more precisely. Further, if the image is compressed and the compressed image data is transmitted to the control center using a line for transmitting the detection / measurement result, the cost associated with the image data transmission can be suppressed.

According to the first aspect of the present invention, after the image captured by the camera is compressed, the compressed image data is connected to the line for transmitting the detection / measurement result of the traffic condition obtained by the image processing of the captured image. It is shared and transmitted to the control center. By simply adding a compression circuit and its control system to the conventional vehicle monitoring device, image data can be transmitted to the control center at low cost, and the traffic condition can be visually recognized at the control center. Moreover, since the compressed image data is transmitted, the image data can be transmitted in a short time.

According to the second aspect of the present invention, the compression rate of the image is arbitrarily changed according to the instruction from the control center.
Depending on the monitoring purpose on the control center side, it is possible to selectively use a case of transmitting a large amount of low image quality image data at a high speed or a case of transmitting a high image quality image data although it takes a little time.

According to the third aspect of the present invention, the image compression rate is changed according to whether the traffic condition is normal or abnormal. When the traffic condition is normal, the compression ratio is set high, and when it is determined that the traffic condition is abnormal, the compression ratio is set low. By doing this, when the traffic center is in a normal traffic state that does not need to be monitored so much, and when the traffic center is in an abnormal traffic state that needs to be monitored in detail, High-quality images can be automatically selected and provided to the control center. Therefore, even if the control center does not constantly monitor the traffic condition, the image can be confirmed with an appropriate image quality according to the situation.

According to the fourth aspect of the present invention, the compression rate of only the image data in the area having the abnormal traffic condition is lowered. Then, only the image of the area to be monitored in detail has high image quality, and accurate information can be obtained in an abnormal traffic state without increasing the amount of transmitted data.

According to the fifth aspect of the present invention, when it is determined that the traffic condition is abnormal, the compressed image data in the normal traffic condition before the determination is transmitted to the control center. Therefore, on the control center side, both images before and after the occurrence of the abnormal traffic condition can be viewed, and more accurate information about the abnormal traffic condition can be obtained.

According to a sixth aspect of the present invention, a difference image,
The edge image and / or the partial image is compressed, and the compressed image data is transmitted to the control center. Therefore, it is possible to quickly transmit as much necessary image data to the control center as possible within the limited transmission capacity of the line.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to the drawings showing the embodiments thereof. FIG. 1 is a schematic diagram showing the overall configuration of a vehicle monitoring device of the present invention.

C is placed on the top of the pole erected near the road.
A camera unit 20 with a built-in CD camera 1 is provided,
A monitoring device body 30 is attached to the bottom of the pole.
Reference numeral 40 denotes a central control center that manages and controls traffic conditions on the road, and a line 50 is provided between the control center 40 and the monitoring device main body 30.

FIG. 2 is a block diagram showing an apparatus provided in the control center 40. As shown in FIG. 2, the control center 40 includes a transmission / reception circuit 41, an image expansion circuit 42, and a monitor T.
A V43 and an input unit 44 are provided. Transmitter / receiver circuit 41
Performs transmission / reception with the monitoring device main body 30. Image decompression circuit 42
Expands the compressed image data input from the monitoring device main body 30 via the line 50 and the transmission / reception circuit 41 to the original image signal and outputs the expanded image signal to the monitor TV 43. In addition, various information on the detection and measurement results of traffic conditions obtained by the monitoring device main body 30
It is output to the monitor TV 43 via 50 and the transmission / reception circuit 41. The monitor TV 43 displays an image corresponding to the image signal, and also displays various information on the detection / measurement result of the traffic condition. In addition, the input unit 44 is instruction information to the monitoring device body 30 (compression rate, information for instructing and setting an image to be compressed).
Is used when the observer in the control center 40 inputs.

FIG. 3 is a block diagram showing the internal structure of the monitoring device main body 30. As shown in FIG. 3, the monitoring device main body 30 includes an A / D converter 2, image memories 3 and 4, image creation circuits 5 and 8, an image compression circuit 6, shared memories 7 and 9, and a main memory.
10, CPU 11, I / O circuit 12, transmission / reception circuit 13, switch
It has 14 and an indicator 15. Image creation circuits 5, 8, image compression circuit 6, shared memories 7, 9, main memory 10, CPU 11,
The I / O circuit 12 and the transmission / reception circuit 13 are connected to the CPU 11 as a microprocessor via the CPU bus.

As shown in FIG. 1, the field of view of the CCD camera 1 extends over all lanes of a road having four lanes. The CCD camera 1 images the road condition of four lanes, and an analog image signal is converted into an A / D converter. Enter 2. The A / D converter 2 digitizes the input analog image signal and stores the original image for digital image signal transmission, and an image memory 3 for detecting and measuring various information on traffic conditions. And outputs it to the image memory 4 for storing the original image for use.

An image signal is read from the image memory 3 to the image forming circuit 5, and the image forming circuit 5 performs image preprocessing such as difference processing on the read image signal if necessary, and based on the original image. Create a new image. FIG. 4 is a block diagram showing the configuration of the image creating circuit 5. The image creating circuit 5 includes a first difference image creating unit 51, a second difference image creating unit 52, an edge image creating unit 53, a partial image creating unit 54,
It has a reference image memory 55. In the reference image memory 55,
A reference image of only the road where no vehicle exists is stored. The data of the reference image may be obtained by photographing the road surface in the early morning when no vehicle is present, or may be obtained by deleting only the vehicle from the normal photographed image.

The first difference image creating section 51 obtains the difference between the original image from the image memory 3 and the reference image stored in the reference image memory 55, and compresses the difference image (first difference image). Output to the circuit 6. The second difference image creation unit 52
The original image at the current time and the original image before the predetermined time are input from the image memory 3, the difference between the two images is calculated, and the difference image (second difference image) is output to the image compression circuit 6. The edge image creation unit 53 performs a spatial differentiation process on the original image from the image memory 3 to obtain an edge image in which the contour of the vehicle, that is, a portion where the contrast of the light and dark changes drastically is raised, and outputs it to the image compression circuit 6. To do. The partial image creation unit 54 uses the image memory 3
An image of a partial area is extracted from the original image from, the image obtained by cutting out only the road portion into a predetermined rectangular area is extracted, and the extracted partial image is output to the image compression circuit 6. If such image preprocessing is not performed, the original image is directly input to the image compression circuit 6 through the image creation circuit 5.

The image compression circuit 6 selects image data to be transmitted, and selects, for example, JPE for the selected image data.
A compression process by the G (Joint Photographic Experts Group) system is performed, and the compressed image data is output to the shared memory 7. The shared memory 7 stores this compressed image data. The JPEG method is an adaptive discrete cosine transform (Adap
tive Discrete Cosine Transform) is a high-efficiency coding method.

The image signal is read from the image memory 4 to the image forming circuit 8, and the image forming circuit 8 performs image preprocessing for vehicle detection, moving vehicle group detection, etc. on the read image signal. The image creating circuit 8 has an internal configuration similar to that of the image creating circuit 5 described above, and includes a first difference image, a second difference image,
The edge image and the partial image are obtained, and the image data is output to the shared memory 9. The shared memory 9 stores this image data.

The CPU 11 detects the vehicle, measures the speed, and measures the speed based on the preprocessed image data stored in the shared memory 9.
Vehicle type detection, parking detection, traffic flow abnormality detection, etc. are performed to obtain traffic status information. The main memory 10 temporarily stores image data and compressed image data for detection / measurement processing in the CPU 11.

The switch 14 is used when switching the operation mode of the monitoring device main body 30. The display unit 15 displays the measurement result such as the length of traffic jam and the operating state of the entire device. Input / output of the switch 14 and the display 15 is controlled via the I / O circuit 12. The transmitter / receiver circuit 13 is a control center 40
Send and receive operations with. Specifically, the monitoring device body
The transmitting / receiving circuit 13 transmits various information of the traffic condition obtained by the CPU 11 and the compressed image data obtained by the image compressing circuit 6 to the control center 40 via the line 50 from the transmitting / receiving circuit 13 and sends the instruction information (compression ratio Information for instructing, information for instructing an image to be compressed, etc.) from the control center 40 via the line 50
Receive at 13.

Next, the operation will be described. FIG. 5 is a diagram showing a basic processing procedure in the vehicle monitoring device of the present invention.

First, the CCD camera 1 provided above the road captures a road including a passing vehicle at a constant cycle to obtain a still image (S1). The analog image signal of the still image obtained by the CCD camera 1 is sent to the A / D converter 2 and converted into a digital image signal, and the digital image signal is detected by the image memory 3 for image data transmission and traffic state detection. It is stored in the image memory 4 for measurement (S2).

An image signal is read from the image memory 4 to the image forming circuit 8 and pre-processing of the image necessary for obtaining various information of the traffic condition afterwards is performed to obtain the first difference image and the second difference image.
Difference images, edge images, partial images, etc. are obtained (S
3). Then, an individual vehicle is detected based on the preprocessing result of this image (S4). In this detection process, for example,
2 for edge images obtained by spatially differentiating still image data
The binarization process is performed, and the vehicle is detected from the result of the binarization process by the pattern matching method. In addition, the first
The vehicle may be detected by recognizing an object remaining in the first difference image based on the difference image.

Next, a tracking process of individual vehicles is performed (S
5). In the tracking process, the vehicle position detected before the predetermined time and the vehicle position detected this time are compared based on the second difference image described above, and the same vehicle is tracked. Next, calculation processing of various parameters of the traffic flow is performed (S6). In this calculation process, the speed is measured based on the vehicle tracking result, and the vehicle type is detected from the vehicle width, the vehicle length, and the like.

Further, processing for detecting the state of parking / abnormal traffic is carried out (S7). In this detection process, the vehicle whose speed calculated in S6 is 0 is recognized as a stopped vehicle, and the parked vehicle on the roadside and the accident are considered in consideration of the stop position, the stop time, the traffic flow situation of the surrounding lanes, and the like. Detects anomalies in traffic flow due to factors such as Specifically, in the parking detection, a vehicle that has been stopped continuously in the roadside lane for a longer time than a certain time (one cycle of a traffic light or more) or behind the parked vehicle in the measurement range. The vehicle is determined to be parked. In the abnormal traffic detection, if there is no vehicle that stops or slows down in the measurement range, but there is a vehicle that is continuously stopped for a certain period of time, or if there is no traffic for a certain period of time. In this case, it is judged as an abnormal traffic condition due to an accident or the like.

Further, the moving range of the vehicle group is detected based on the result of the image preprocessing by the image forming circuit 8 (S8). In this detection processing, the moving range is detected by comparing the image before the predetermined time with the current image, that is, by referring to the above-described second difference image. Next, the congestion length of the vehicle is calculated (S
9). In this calculation process, in S8, when the movement range is 0 or very narrow, that is, the range in which the vehicle group is not moving or hardly moves is set as the congestion range of the vehicle, and the congestion length is calculated.

Here, the compression condition information is received from the control center 40 via the line 50 (S10). The compression condition information includes information that specifies the compression rate, information that specifies the capturing interval of the compressed image data, which image among the first difference image, the second difference image, the edge image, the partial image, and the original image. Information that specifies whether compression processing should be performed is included.

The image signal is read out from the image memory 3 to the image forming circuit 5, the image is preprocessed, and the first difference image, the second difference image, the edge image, the partial image and the like are obtained (S11). . Then, following the instructions from the control center 40,
The image to be compressed is subjected to, for example, the JPEG compression process in the image compression circuit 6, and compressed image data is obtained (S12).

The various parameters of the traffic flow, the detection / measurement results of the parking / abnormal traffic, the congestion length, etc., and the compressed image data are transmitted to the control center 40 via the line 50 (S13).

In the above example, the compression condition is set in accordance with the instruction from the control center 40, but it is also possible to set the compression condition on the monitoring device main body 30 side based on the detection result of the traffic condition. Another embodiment of the present invention in which the compression condition is set on the monitoring device main body 30 side will be described below with reference to FIG. 6 showing the processing procedure.

In FIG. 6, S1 to S9 are the same as those in FIG.
Since the processing is the same as the case of 1, the description thereof will be omitted.
Parking / abnormal traffic detection processing (S7), congestion length calculation processing (S
After performing the process of 9), the CPU 11 sets the compression condition (S20). The compression condition includes a compression rate, a method of creating a compressed image (which image is subjected to the compression process), an interval for capturing the compressed image data, and the like. These compression conditions are set based on the results of the detection / calculation processing in S7 and S9. Specifically, whether parking is detected in S7, abnormal traffic is detected, or S
In 9, the compression condition is set depending on whether or not the congestion length is a certain length or more.

For example, if no abnormal traffic is detected, the compression rate is set high, and if abnormal traffic is detected, the compression rate is set low. In this way, if abnormal traffic occurs, the compression rate will automatically decrease, and you will be able to see high-quality images on the control center side, and more accurate information can be captured instantaneously. it can. In addition, the compression rate decreases only when abnormal traffic occurs, so in normal traffic conditions that do not require detailed monitoring on the control center side,
A low-quality image is presented, and waste in the amount of transmitted data is eliminated. In this case, only the compression rate for the image in the area where the abnormal traffic is detected may be set low.

The process after setting the compression rate (S11,
Since S12 and S13) are the same processes as in the case of FIG. 5 described above, description thereof will be omitted.

The vehicle monitoring devices according to the two embodiments as described above have the following features in the transmission of image data to the control center.

Since the compressed image data is transmitted to the control center using the line for transmitting the detection / measurement result as it is,
There is no additional line usage cost as compared to the case of using a dedicated line like a normal surveillance camera. Further, since the still image data is targeted for transmission and the still image is compressed to reduce the transmission capacity, a line with a small capacity can be used and the transmission can be performed in a short time.

Further, image data compressed at an appropriate compression rate corresponding to the detection / measurement result can be transmitted to the control center,
Moreover, this compression rate can be set on the control center side or the monitoring device body side. At this time, if the compression rate is increased, the data can be transmitted in a short time, but the image quality recognized by the control center side is deteriorated. On the contrary, if the compression rate is low, it takes a long time for transmission, but the image quality is high. Therefore, for example, when abnormal traffic such as an accident is detected, even if the transmission time is long, the compression rate is lowered so that a clearer image can be recognized on the control center side.

Further, it is possible to transmit not only the compressed data of the entire image but also the compressed data of a part of the photographed image. At this time, the required image area to be transmitted can be arbitrarily designated on the control center side or the monitoring device body side. For example, when the occurrence of an accident is detected, if the compressed image data of only the peripheral portion is transmitted, the data amount is reduced and the transmission can be performed at higher speed. Also, since only the compressed image data of a part of the area is sent, it is possible to provide a high quality image with a lower compression rate than in the normal case within the same data amount range.

The compressed image data can be constantly transmitted by making full use of the capacity of the transmission line, or the compressed image data can be transmitted at an arbitrary time corresponding to the detection / measurement result. . At this time, the presence or absence of transmission of compressed image data can be designated on the control center side or the monitoring device body side.
For example, if abnormal traffic such as an accident or parking is detected,
Alternatively, the compressed image data is transmitted so that the traffic condition can be recognized more accurately only when the measured congestion length reaches or exceeds a predetermined length. Further, the cycle of capturing images taken by the CCD camera can be arbitrarily designated on the control center side or the monitoring device body side.

By temporarily storing the temporally continuous original image data or compressed image data in the memory, it is possible to provide the control center with a temporally continuous image. At this time, it is advantageous in terms of memory capacity to store the compressed image data. On the other hand, storing the original image data has an advantage that the compression rate can be arbitrarily set. Further, the control center side or the monitoring device body side can specify how far back compressed image data is transmitted. For example, when abnormal traffic such as an accident is detected, continuous compressed image data immediately before the occurrence of the accident can be transmitted, and the cause of the accident can be recognized.

As described above, the image data having the image quality and the time interval according to the monitoring purpose at the control center can be transmitted. For example, when abnormal traffic is detected by image processing, the captured image capturing cycle is shortened in the time period before and after the occurrence of abnormal traffic, and compressed to a relatively high image quality and temporarily stored in memory. After that, it is transmitted to the control center. Further, in the event of a disaster, according to a command from the control center, the transmission rate can be reduced by increasing the compression rate even though the image quality is low, so that the data can be transmitted faster.

[0057]

As described above in detail, in the first invention, after compressing the image photographed by the camera, the compressed image data is transmitted to the control center through the same line as the traffic condition detection / measurement result. Therefore, the image data can be inexpensively transmitted to the control center and the image can be viewed at the control center simply by adding the image compression circuit and its control system to the conventional vehicle monitoring device. Further, since the detection / measurement result and the transmission line are shared, the introduction cost and the operation cost can be significantly reduced as compared with the case where a monitoring ITV camera is newly installed.

Further, according to the second aspect of the invention, since the image compression rate can be arbitrarily changed in accordance with the instruction from the control center, the image quality and the transmission speed can be controlled by the control center according to the monitoring purpose of the control center.

Further, according to the third aspect of the invention, since the image compression rate can be arbitrarily changed according to whether the traffic condition is normal or abnormal, when the traffic condition is normal, a low-quality image is displayed in the abnormal traffic condition. In some cases, high-quality images can be automatically selected and provided to the control center. Even if the control center does not constantly monitor traffic conditions, the images can be confirmed with appropriate image quality.

Further, according to the fourth aspect of the invention, since the compression rate of only the image data in the area having the abnormal traffic condition is lowered and only the image of the area to be monitored in detail has the high image quality, the transmission data amount is too small. Accurate information can be obtained during abnormal traffic conditions without increasing the number.

Further, in the fifth invention, when it is determined that the traffic condition is abnormal, the compressed image data before and after the determination is transmitted to the control center so that both the images before and after the occurrence of the abnormal traffic condition are displayed. Since it is provided to the control center, more accurate information in abnormal traffic conditions can be obtained.

Furthermore, in the sixth invention, the difference image, the edge image and / or the partial image is compressed and the compressed image data is transmitted to the control center, so that the amount of data to be transmitted can be reduced and the minimum required compressed image can be obtained. Data can be quickly transmitted to the control center.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an installation example of a vehicle monitoring device of the present invention.

FIG. 2 is a block diagram showing an installation device in the control center in the vehicle monitoring device of the present invention.

FIG. 3 is a block diagram showing an internal configuration of a monitoring device body of the vehicle monitoring device of the present invention.

FIG. 4 is a block diagram showing an internal configuration of an image creation circuit in the monitoring device body.

FIG. 5 is a diagram showing a basic processing procedure in the vehicle monitoring device of the present invention.

FIG. 6 is a diagram showing a basic processing procedure in the vehicle monitoring device of the present invention.

[Explanation of symbols]

 1 CCD camera 5, 8 image creation circuit 6 image compression circuit 11 CPU 13, 41 transmission / reception circuit 20 camera unit 30 monitoring device body 40 control center 44 input section 50 line 51 first difference image creation section 52 second difference image creation section 53 Edge image creation part 54 Partial image creation part

Claims (6)

[Claims] 1. A vehicle monitoring device for photographing a passing vehicle with a camera, detecting a traffic condition based on the photographed image, and transmitting the detection result to a control center, and a compression means for compressing the image of the vehicle. A vehicle monitoring apparatus comprising: a transmission unit that transmits the compressed image data and the detection result to the control center through the same line. 2. A vehicle monitoring device for photographing a passing vehicle with a camera, detecting a traffic condition based on the photographed image, and transmitting the detection result to a control center, and a compression means for compressing the image of the vehicle, A transmission means for transmitting the compressed image data and the detection result to the control center through the same line; and a setting means for setting a compression rate in the compression means in accordance with an instruction from the control center side. Characteristic vehicle monitoring device. 3. A vehicle monitoring device for photographing a passing vehicle with a camera, detecting a traffic state based on the photographed image, and transmitting the detection result to a control center. A normal traffic state based on the detection result. Determination means for determining whether the vehicle is in an abnormal traffic state, compression means for compressing the image of the vehicle, and setting the compression rate in the compression means to be lower than that in the normal traffic state when determining the abnormal traffic state And a transmission unit configured to transmit the compressed image data and the detection result to the control center via the same line. 4. The setting means is configured to set the compression rate to be lower for only an image of an area having an abnormal traffic condition than when the traffic condition is normal. Vehicle monitoring device. 5. A compressed image before storing the abnormal traffic condition, comprising storage means for storing the original image data obtained by the camera or compressed compressed image data, and when the judging means determines the abnormal traffic condition. The vehicle monitoring device according to claim 3, wherein the vehicle monitoring device is configured to transmit data to the control center. 6. A first image creating circuit for creating a differential image between a captured image obtained by the camera and a reference image showing a road surface on which no vehicle exists, a differential image between two captured images obtained at different times. A second image creating circuit for creating, a third image creating circuit for creating an edge image obtained by differentiating a captured image,
And at least one image creating circuit of a fourth image creating circuit for creating a partial image by extracting a part of the photographed image, the first, second, third and / or fourth image creating circuit The vehicle monitoring device according to any one of claims 1 to 5, wherein the image created in (1) is configured to be compressed by the compression unit.