JP2000184354A - Image transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically revise the number of communication lines in response to fluctuation in transmitted image data or the like in an image transmission system. SOLUTION: The image transmission system where a transmitter 1 transmitting image data of a camera or the like and a receiver 3 receiving the transmitted image data are interconnected by plural) communication lines 2, is provided with a line setting means (transmission section 28, a control section 29) that sets the number of communication lines and with an image fluctuation detection means (image processing section 18 and control section 29) or the like that detects fluctuation in image based on the image data from the camera all or the like, and the line setting means sets the number of the communication lines in response to fluctuation in the image. A luminance fluctuation detection section 18a detects each fluctuation in average luminance or maximum luminance and a motion vector detection section 18b detects magnitude of a motion vector of a mobile body or the like as fluctuation of the image. Or the detection above may be conducted in a prescribed area set by an area setting section 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image transmission system, and more particularly, to an image transmission system in which a transmission side and a reception side are connected by a plurality of communication lines, and is capable of reducing fluctuations in image data to be transmitted. Related to the setting of the number of communication lines.

[0002]

2. Description of the Related Art There is an image transmission system in which a transmitting side for transmitting image data and a receiving side for receiving the image data are connected by a plurality of communication lines. FIG. 3 is a main block diagram showing an example of a basic configuration of an image transmission system for transmitting image data of a plurality of monitoring cameras. In the figure, 31, 32,
33 is a surveillance camera, 34 is a transmission device that transmits camera images,
Reference numeral 35 denotes a plurality of communication lines, and reference numeral 36 denotes a receiving device. When sending data with a large amount of information, such as image data,
In many cases, a plurality of communication lines are used. This communication line is usually rented from a communication carrier for a fee. For example, "INS" which is known as a representative communication line
In the case of "Net 64", the transmission capacity of one line is 64 Kbps
This is usually expressed as one unit for two lines (transmission capacity = 64
× 2 = 128 Kbps) and a contract is made to use a plurality of units. On the other hand, when transmitting image data, there are, for example, a case where it is necessary to transmit the image data with high image quality and a case where such image data is not required. In this case, the former requires a larger number of lines, but the latter can reduce the number of lines. Therefore, changing the number of lines according to the transmission image quality makes the use of lines economical. Conventionally, the number of communication lines has been set by a person for the transmitting device 34.

[0003]

As described above, in the prior art, the number of communication lines has been set by a person in the transmitting device 34 (FIG. 3). However, due to the setting by a person, the number of lines may exceed the number of lines originally required. In this case, an extra line usage fee will be paid.
Further, after the number of lines is set for high image quality transmission, the set state may be used for subsequent communication as it is.
In this case, too, an extra line usage fee will be paid. As described above, in the related art, there is a disadvantage that an extra line usage fee is paid because the number of lines is not appropriately changed and set. It is also a problem to be improved from the viewpoint of effective use of communication lines. Therefore, if the setting of the number of lines can be automatically set as required without depending on a person, the above-mentioned drawbacks and problems can be solved. The present invention has been made from such a viewpoint, and an object of the present invention is to provide an image transmission system in which the number of communication lines is automatically set according to the state of various images and the like and data is transmitted. .

[0004]

SUMMARY OF THE INVENTION The present invention provides an image transmission system in which a transmitting side for transmitting image data, such as a camera, and a receiving side for receiving the transmitted image data are connected by a plurality of communication lines. A line setting means for setting the number of lines of the communication line; and an image fluctuation detecting means for detecting a fluctuation of an image based on the image data, wherein the line setting means communicates according to the fluctuation of the image. It is an object to provide an image transmission system in which the number of lines is set.

Further, the image fluctuation detecting means is an average luminance fluctuation detecting means for detecting whether the fluctuation of the image average luminance in a field unit or a frame unit deviates from a predetermined average luminance width.

Alternatively, the image fluctuation detecting means is a maximum luminance fluctuation detecting means for detecting whether the fluctuation of the image maximum luminance in a field unit or a frame unit deviates from a predetermined maximum luminance width.

Further, an area setting means for setting a monitoring area in the image data may be provided, and the detection may be performed in the monitoring area set by the area setting means.

[0008] The image fluctuation detecting means may be a motion vector detecting means for detecting whether a motion vector of a moving object extracted from the image data has reached a predetermined magnitude or more.

[0009] A timer unit for measuring the passage of time may be provided, and the line setting means may set the number of communication lines when the detected state has elapsed for a predetermined time or more.

When the detection is made, or when the detected state has passed for a predetermined time or more, the line setting means increases the current number of communication lines to the predetermined number. .

Further, camera turning control means for controlling the turning or zoom setting of the camera is provided, and when a turning control signal to be provided to the turning control means is generated, the current number of communication lines by the line setting means is determined. It is better not to change the setting.

A camera switching means for switching between a plurality of cameras; and a first memory unit which stores in advance the plurality of cameras and the set number of communication lines in association with each other. When the camera is switched by the means, the line setting means sets the number of communication lines for each camera based on the data stored in the first memory unit.

[0013] Further, there is provided a usage fee calculating means for calculating the cumulative usage fee based on the data on the line usage fee transmitted from the owner of the communication line, and the cumulative usage fee becomes equal to or more than a predetermined amount. Sometimes, the line setting means sets the number of communication lines to be reduced to a predetermined number.

Further, input means for inputting the telephone number of the transmission destination, the telephone number of each transmission destination and the set number of communication lines are made to correspond to each other, and the number of lines is reduced and stored in advance in a long-distance area. A second memory unit comprising: a telephone number of a transmission destination input by the input unit; and the line setting unit determines the number of communication lines based on data stored in the second memory unit. To be set.

Further, a pixel number processing means for changing the number of pixels of the image data to be transmitted is provided, and when the line setting means is set to reduce the number of communication lines, the pixel number processing unit sets the number of pixels. Is reduced to a predetermined number of pixels.

Further, there is provided multi-screen processing means for performing multi-screen processing based on a plurality of camera images, and when transmitting image data subjected to multi-screen processing by the multi-screen processing means, the line setting means is provided with a communication line. Is increased to the predetermined number of lines.

Further, a clock section for counting time is provided, and the line setting means sets the number of communication lines according to a predetermined time zone. In this case, it is preferable that the setting of the number of communication lines by the line setting means is to increase the number of communication lines to a predetermined number of lines in a predetermined night discount time zone with respect to a daytime time zone.

[0018]

Embodiments of the present invention will be described below with reference to the drawings based on embodiments. FIG. 1 is a main block diagram showing an embodiment of an image transmission system according to the present invention, in which image data of a plurality of surveillance cameras is transmitted as an example. In FIG. 1, 1 is a transmitting device, 2
Is a communication line composed of a plurality of lines, and 3 is a receiving device.
The present invention is to automatically set the number of communication lines according to various states described below. First, a description will be given of how to change the number of communication lines with respect to a change in image brightness. In camera monitoring, an image with no or little motion may be monitored, but in this case, the luminance of the image is constant in a normal state, or the fluctuation range is limited even if there is luminance fluctuation, and abnormal When this occurs, the luminance varies greatly. Therefore, in such monitoring, the width of the luminance level corresponding to the normal state (hereinafter referred to as reference luminance level width) is set in advance, and if the reference luminance level width is exceeded (when an abnormality occurs), The number of lines is increased with respect to the normal state, and the amount of data transmission per unit time is increased so as to transmit with high image quality.

In FIG. 1, the signals from the cameras a11, b12 and n13 are switched by a camera switching unit 17,
The image data of the switching output is input to the luminance fluctuation detecting unit 18a of the image processing unit 18. The luminance fluctuation detecting section 18a stores the data of the reference luminance level width (memory section) while detecting the luminance of the input image data. As the luminance detection, there are a method of detecting the average luminance in a field unit or a frame unit, and a method of detecting the maximum luminance in the unit. In the former case, the average level of the entire image may be calculated based on each pixel level of the image data (arithmetic unit), and in the latter case, the maximum level is detected from each pixel level of the image data (detecting unit). I just need. The luminance variation detecting unit 18a may be configured by any of the above-described detection methods. In this case, the reference luminance level width is also adjusted to the detection method.

The detected average luminance or maximum luminance is compared with the reference luminance level width (comparing unit), and when the average luminance or the maximum luminance is within the reference luminance level width, it is set as a normal state. Transmission is performed with the number of lines, and if the number of lines deviates from the reference luminance level width, it is determined that an abnormality has occurred, and the number of lines is increased to a predetermined number of lines in a normal state. It is to be noted that "above-mentioned case" means that, as an abnormal state, the average luminance or the maximum luminance may increase or decrease from the reference luminance level width depending on the state, so that it is necessary to detect both fluctuations. It depends. FIG. 2A shows the concept of this luminance variation. The above change in the number of lines
The control unit 29 changes and sets the number of lines in the transmitting unit 28 based on the detection of the luminance fluctuation detecting unit 18a (average or maximum luminance fluctuation detecting means) which is one component of the image quality processing unit 18 under the control of 29 ( Line setting means). The above is the change setting of the number of communication lines with respect to the luminance fluctuation of the image.

Next, a configuration for limiting a monitoring area will be described. Although the above-described luminance fluctuation detection is performed on the entire area of the image, this area may be limited to an important part. Therefore, the area setting unit 19 is provided under the control of the control unit 29 (area setting means), and the area setting unit 19 has area setting data in advance. This area may be set based on the horizontal and vertical synchronization signals. In accordance with the area setting data of the area setting section 19, the control section 29 causes the luminance fluctuation detecting section 18a to detect the fluctuation of the average luminance or the maximum luminance in the same area with respect to the reference luminance level width. Based on the detection, the control unit 29 sets the number of lines in the transmission unit 28 in the same manner as described above. The above is the configuration for limiting the monitoring area.

Next, a description will be given of a configuration for changing and setting the number of communication lines when the motion vector of a moving object in an image is equal to or larger than a predetermined magnitude. FIG. 2B is a conceptual diagram related to a motion vector. The figure shows an example in which an object m has moved a distance L in the direction of the arrow (A → B) in an image. This configuration changes the number of lines in the transmitting unit 28 when the displacement L becomes equal to or larger than a predetermined value. For this reason, a motion vector detecting unit 18b is provided as a component of the image quality processing unit 18 under the control of the control unit 29 (motion vector detecting means), and the image data from the camera switching unit 17 is input thereto, The movement displacement L is detected by the detection unit 18b based on

For this detection, for example, the entire image is repeatedly scanned in units of a predetermined number of pixels (for example, 9 pixels), and luminance (or chromaticity) data of a previously scanned state and a later scanned state is obtained. Compare. By this comparison, displacement of luminance (or chromaticity) data can be detected as positional displacement. This positional displacement becomes a moving displacement (motion vector) L. On the other hand, data relating to the reference displacement Ls is set in advance, and the data is stored (memory unit) in the motion vector detecting unit 18b. The reference displacement Ls is compared with the detected displacement L (comparing unit), and the displacement L <reference displacement
If it is in Ls, it is transmitted with the number of lines set as that in the normal state, and if the displacement L ≥ the reference displacement Ls, the number of lines is increased to a predetermined number of lines as compared to the normal state as an abnormal occurrence . The above is the change setting of the number of lines for the moving object.

Next, a description will be given of a configuration for changing and setting the number of communication lines when each of the above-described detections has continued for a predetermined time or more. This configuration does not change the number of lines immediately after detection as described above when there is each detection (brightness fluctuation, motion vector, etc.), but rather, when the detection continues for a certain period of time or longer, Change and set the number. Therefore, the timer unit 20 is provided under the control of the control unit 29.When each detection is performed, the control unit 29 activates the timer unit 20, and when a predetermined time or more elapses, the timer unit 20 outputs a corresponding signal. Output. When the same output is received, the control unit 29 changes and sets the number of lines in the transmission unit 28. With this configuration, it is possible to provide a function that does not respond to an instantaneous image change such as a vehicle light. The above is the configuration in which the timer unit 20 is provided.

Next, a configuration in consideration of the camera turning function will be described. The surveillance camera is usually turned. In general, the zoom setting of the lens is also performed along with the turning. With this turning function, the image data input to the image processing unit 18 naturally fluctuates when turning the camera or setting the zoom. However, this change is an intentional change and does not indicate occurrence of an abnormality. Therefore, it is desirable to stop the line change function when the camera is turned. In FIG. 1, reference numerals 14, 15, and 16 denote camera driving units that perform camera turning and zoom setting of each of the camera a 11, camera b 12, and camera n 13, and are set and controlled by a control unit 29 via a camera turning control unit 21 ( Camera turning control means). Further, a first input unit 22 is provided under the control of the control unit 29,
22 More specific camera rotation and zoom settings are input. When an instruction such as camera rotation is given from the first input unit 22, the control unit 29 generates and outputs a required rotation control signal S1 to the camera rotation control unit 21, and when the signal S1 is generated and output, the transmission unit Do not change the current line setting in 28. As a result, unnecessary change in the number of lines is prohibited. The above is the configuration in consideration of the camera turning function.

Next, a configuration for changing the number of lines for each camera will be described. When a plurality of monitoring cameras are provided, it may not be necessary to transmit the image data of each camera with the same image quality. For example, when the monitoring target includes the inside of the office and the vicinity of the main gate, the monitoring image in the office is transmitted with normal image quality, and the monitoring image near the main gate is transmitted with high image quality. As a result, the communication line is more effectively used. In FIG. 1, camera a1
1, the camera switching between the camera b12 and the camera n13 is performed by the control unit 29.
This is performed by the camera switching unit 17 under the control of (camera switching means). On the other hand, the first memory unit 23 is provided under the control of the control unit 29, and a plurality of cameras such as the camera a11, the camera b12 and the camera n13 are associated with the set number of communication lines in advance in the memory unit 23. Remember. When the camera is switched by the camera switching unit 17, the control unit 29 sets the number of lines in the transmission unit 28 for each camera based on the switching signal used for the switching and the data stored in the first memory unit 23. . The above is the configuration in which the number of lines is changed for each camera.

Next, a configuration for changing the number of communication lines according to the accumulated usage fee of the communication lines will be described. When a communication line is used, data relating to the line usage fee is transmitted from the owner (operator) every time the communication line is used. The line usage fee is accumulated, and when the accumulated amount exceeds a predetermined amount, the number of communication lines is reduced to the predetermined number. As a result, it is possible to automatically suppress an excess of the budget related to the use of the communication line.
Therefore, the usage fee calculation unit 24 is provided under the control of the control unit 29 (use fee calculation means), and receives data related to the line usage fee transmitted from the communication line owner via the communication line in the transmission unit 28, This is cumulatively calculated by the usage fee calculation unit 24. If this accumulated amount is equal to or greater than the predetermined amount,
The control unit 29 reduces the number of communication lines in the transmission unit 28 to a predetermined number. The above is the configuration in which the number of communication lines is changed according to the accumulated usage fee of the communication lines.

Next, a configuration for changing the number of communication lines according to the telephone number of the transmission destination will be described. There are various destinations for transmitting image data from short distance to long distance. In this case, by increasing the number of lines for short distances and decreasing the number of lines for long distances, it is possible to suppress an increase in line usage charges. The distance to the transmission destination can be determined from the city code of the telephone number input at the time of transmission. Therefore, a second input unit 25 for inputting the telephone number of the transmission destination is provided under the control of the control unit 29 (input means), and the telephone number of each transmission destination is set to correspond to the set number of communication lines. A second memory unit 26 stored in advance is provided under the control of the control unit 29. The second memory unit 26 stores a predetermined number of lines for a long-distance telephone number so as to reduce the number of lines. When the telephone number of the transmission destination is input from the second input unit 25, the second
The control unit 29 sets the number of communication lines in the transmission unit 28 based on the data relating to the telephone number and the set number of lines in the memory unit 26. As a result, the number of lines increases for short distances, and decreases for long distances. The above is the configuration for changing the number of communication lines according to the telephone number of the transmission destination.

Next, a description will be given of a configuration in which, when the number of communication lines is set so as to be reduced, the number of pixels of image data to be transmitted is reduced. If the number of communication lines is reduced, the data transmission speed is reduced, and if the number of pixels is not changed, the number of transmitted image frames per unit time is reduced. Depending on the purpose of the surveillance system, there may be a case where it is desired to avoid a decrease in the number of image frames even if a decrease in the resolution is acceptable. This configuration is effective in such a case. Therefore, a pixel number processing unit 18c that performs a process of changing the number of pixels on image data to be transmitted is provided as a component of the image processing unit 18 under the control of the control unit 29 (pixel number processing unit).
When the control unit 29 sets to reduce the number of communication lines in the transmitting unit 28, the same pixel number processing unit 18c causes the number of pixels to be reduced to a predetermined number of pixels. This reduction in the number of pixels may be performed by a process of thinning out pixel data to a predetermined number in accordance with the related art. As described above, a decrease in the number of transmitted image frames can be avoided. The above is the configuration of the pixel number reduction processing when the number of lines is reduced.

Next, a configuration for changing the number of communication lines when transmitting image data subjected to multi-screen processing based on a plurality of camera images will be described. When transmitting a monitoring image, a plurality of camera images such as the camera a11, the camera b12, and the camera n13 need to be subjected to multi-screen processing (for example, four-screen processing) and then transmitted in order to simultaneously monitor multiple screens on the receiving side. . When the multi-screen processing is performed, it is necessary to increase the number of lines and prevent the image quality from lowering. Therefore, a multi-screen processing unit 18d is provided as a component of the image processing unit 18 under the control of the control unit 29 (multi-screen processing means), and the signals of the respective camera images are input to the processing unit 18d. Process the screen. When performing this multi-screen processing, the control unit 29 sets the number of communication lines in the transmission unit 28 to be increased to a predetermined number of pixels. This prevents the image quality of the multi-screen image from deteriorating. The above is the configuration for changing the number of communication lines when transmitting image data subjected to multi-screen processing.

Next, a configuration for changing the number of communication lines according to a time zone will be described. Nighttime charges for communication lines are generally lower than during the day. Therefore, the number of lines can be increased at night when the usage fee is low, and the economics of using the lines can be improved.
Therefore, a clock unit 27 for counting time is provided under the control of the control unit 29, and the control unit 29 sends the clock to the transmission unit according to a predetermined time zone.
As for the setting of the number of communication lines in 28, in addition to the method of increasing the number of lines at night as described above, a time zone is set according to the purpose of the monitoring system, and the number of lines is increased or decreased accordingly. It may be. The automatic setting of the number of communication lines according to various states has been described above.
Is a configuration incorporating all of these functions. However, it is optional to incorporate all functions, and it is free to configure by deleting some functions. Image data is transmitted to the receiving device 3 via the communication line 2 having the number of lines set as described above, and is displayed on the monitor 3a. It should be noted that the data of the set number of lines set by the transmission / reception unit 2 is transmitted to any one of the communication lines 2 while being included in other data. Therefore, the receiving side may connect the line based on this data.

[0032]

As described above, according to the present invention, the number of communication lines is automatically set in accordance with various conditions such as fluctuations in image brightness or the magnitude of a motion vector of a moving object, so that a pay line is required. Economy of use can be improved. That is, in the related art, there is a disadvantage that an extra line usage fee is paid because the number of lines is not appropriately changed and set. This disadvantage is also a problem to be improved from the viewpoint of effective use of the communication line. The present invention solves the above-mentioned drawbacks and problems, and can be said to contribute to improving the economic efficiency of an image transmission system.

[Brief description of the drawings]

FIG. 1 is a main block diagram showing an embodiment of an image transmission system according to the present invention.

FIG. 2 is an explanatory diagram related to FIG. 1;

FIG. 3 is a main block diagram showing a basic configuration for explaining a conventional image transmission system.

[Explanation of symbols]

 1 Transmission device 11, 12, 13 Surveillance camera 14, 15, 16 Camera drive unit 17 Camera switching unit 18 Image processing unit 18a Brightness fluctuation detection unit 18b Motion vector detection unit 18c Pixel number processing unit 18d Multi-screen processing unit 19 Area setting unit 20 Timer unit 21 Turning control unit 22 First input unit 23 First memory unit 24 Charge calculation unit 25 Second input unit 26 Second memory unit 27 Clock unit 28 Transmission unit 29 Control unit 2 Communication line 3 Reception Device 3a Monitor

Claims (15)

[Claims] An image transmission system in which a transmitting side for transmitting image data of a camera or the like and a receiving side for receiving the transmitted image data are connected by a plurality of communication lines.
Line setting means for setting the number of lines of the communication line, and image fluctuation detecting means for detecting a fluctuation of an image based on the image data, wherein the line setting means changes the communication line according to the fluctuation of the image. An image transmission system wherein the number of lines is set. 2. The apparatus according to claim 1, wherein said image fluctuation detecting means comprises an average luminance fluctuation detecting means for detecting whether the fluctuation of the image average luminance in a field unit or a frame unit deviates from a predetermined average luminance width. The image transmission system according to claim 1. 3. The image fluctuation detecting means comprises a maximum luminance fluctuation detecting means for detecting whether a fluctuation of an image maximum luminance in a field unit or a frame unit deviates from a predetermined maximum luminance width. The image transmission system according to claim 1. 4. An apparatus according to claim 1, further comprising an area setting means for setting a monitoring area in said image data, wherein said detection is performed within the monitoring area set by said area setting means. The image transmission system according to claim 2 or 3. 5. The apparatus according to claim 1, wherein said image variation detecting means comprises a motion vector detecting means for detecting whether a motion vector of the moving object extracted from said image data has become a predetermined magnitude or more. The image transmission system according to the above. 6. A timer unit for measuring the passage of time is provided,
4. The communication system according to claim 1, wherein the line setting means sets the number of communication lines when the detected state has elapsed for a predetermined time or more.
An image transmission system according to claim 4. 7. When the detection is made, or when the detected state elapses for a predetermined time or more, the line setting means increases the current number of communication lines to a predetermined number. The image transmission system according to claim 1, 2, 3, 4, 5, or 6, wherein 8. A camera turning control means for controlling turning or zooming of the camera, etc., is provided. When a turning control signal to be supplied to the turning control means is generated, the current number of communication lines by the line setting means is determined. 2. The image transmission system according to claim 1, wherein said setting is not changed. 9. A camera switching means for switching a plurality of cameras, and a first memory unit which stores in advance the plurality of cameras and the set number of communication lines in correspondence with each other, and 2. The image transmission according to claim 1, wherein when the camera is switched by the means, the line setting means sets the number of communication lines for each camera based on data stored in the first memory unit. system. 10. A usage fee calculating means for calculating an accumulated usage fee based on data on a line usage fee transmitted from an owner of the communication line, wherein the accumulated usage fee becomes equal to or greater than a predetermined amount. 2. The image transmission system according to claim 1, wherein said line setting means sets the number of communication lines to be reduced to a predetermined number of lines when the number of communication lines is reduced. 11. An input means for inputting a telephone number of a transmission destination, a correspondence between the telephone number of each transmission destination and the set number of communication lines, and the number of lines is reduced and stored in advance in a long distance area. A second memory unit comprising: a telephone number of a transmission destination input by the input unit; and the line setting unit determines the number of communication lines based on data stored in the second memory unit. 2. The image transmission system according to claim 1, wherein the image transmission system is set. 12. A pixel number processing means for performing a process of changing the number of pixels for image data to be transmitted, and when the line setting means sets the number of communication lines to be reduced, the number of pixels processing unit sets the number of pixels. 2. The image transmission system according to claim 1, wherein is reduced to a predetermined number of pixels. 13. Multi-screen processing means for performing multi-screen processing based on a plurality of camera images is provided, and when transmitting image data subjected to multi-screen processing by the multi-screen processing means, the line setting means is provided with a communication line. 2. The image transmission system according to claim 1, wherein the number of lines is set to be increased to a predetermined number. 14. An image transmission according to claim 1, further comprising a clock section for counting time, wherein said line setting means sets the number of communication lines according to a predetermined time zone. system. 15. The setting of the number of communication lines by the line setting means according to the time period, the predetermined night discount time period is set to a predetermined number of lines for the daytime time period. 15. The method according to claim 14, wherein the number is increased.
The image transmission system according to the above.