EP0578671B1 - Tv-based monitoring system - Google Patents

Abstract

The invention concerns a TV-based monitoring system which detects movements in the images recorded by a TV camera. When a movement is detected, the image sector concerned is compared with models stored in a memory (MS) containing a multiplicity of models. If a matching model is found, it is transmitted by a transmission line (L) for display on a monitor at the other end of the line. In this way, the person observing the monitor, or, in the case of several cameras, the several monitors associated with these cameras, can be informed rapidly and unequivocally of the use of a particular object in the area being monitored.

Description

The invention relates to a television monitoring system, comprising at least a television camera, a processing device and at least one monitor for reproducing the images recorded by the television camera, the processing device being designed as an electronic motion detector, electronically monitoring the recorded images and generating an alarm message when the image changes.

Such a television monitoring system is already known. For example, DE-PS 3214 254 describes a method for detecting movements in video camera images, in which certain parts of the image are marked in a given image. These parts of the image are used to form the average brightness value, which is compared with the subsequent images over a longer period of time in order to be able to detect movement on the image in this way.

If a movement on the image can also be recognized by an appropriate evaluation of the image signals, it is difficult for a monitor person on the screen to clearly recognize the type and meaning of the movement on the object to be monitored, in order to be able to trigger appropriate measures, despite an alarm message.

The object of the invention is to design a television monitoring system such that the person watching the monitor is informed quickly and particularly clearly about the new situation on the object to be monitored.

This object is achieved in that the processing device has a memory with the image information of a plurality of patterns, that in the event of an alarm message by a comparison device, that part of the image recorded is compared with all the patterns in the pattern memory in which the change has taken place, and in that Matching a pattern whose image information is read from the pattern memory, transferred to the monitor and used there to display the pattern in question.

The sample memory contains the representation of a large number of possible objects (for example impact drill, pistol, hammer, knife, etc.), which are compared with that part of the image in which the change (= movement) took place. By displaying the identified object on the monitor, the person watching is quickly and clearly informed about the new situation at the object to be monitored.

This object is also achieved in that a large number of television cameras are connected to the processing device, that the image information recorded at regular time intervals is stored in a dedicated image memory in each case, that cyclical partial information is read out of all image memories and via a narrow-band transmission line nested to a common monitor with a buffer or to the respective monitor permanently assigned to the television camera in question with an individual buffer that the processing device has a memory with the image information of a large number of patterns, that in the event of an alarm message by a comparison device that part of the image recorded Image of the television camera in question compared with all patterns of the memory in which the change has taken place that, if a pattern matches, its image information from the memory is used for the common monitor or for the monitor assigned to the television camera in question and there for displaying the pattern in question and that either automatically or on request from the other side, only the image information of that image memory is then transmitted to the monitor assigned to the television camera in question, the television camera of which recorded the image change.

A common transmission line is sufficient for the transmission of the image information, preferably in compressed form, even if the partial information is transmitted interleaved from the image memories. In the event of an alarm or after the pattern of the recognized object has been displayed, the transmission line is used exclusively for the transmission of the image information of the television camera which recorded the movement.

Advantageous developments of the invention result from the subclaims.

Fig.1

das Blockschaltbild der Verarbeitungseinrichtung mit den angeschlossenen Fernsehkameras,

Fig.2

das Blockschaltbild für die Behandlung der Bildinformationen auf der Monitorseite und

Fig.3

Schema für die Aufteilung eines Fernsehbildes in Teilinformationen.

The invention is explained in more detail using an exemplary embodiment which is illustrated in the drawing. It shows:

Fig. 1

the block diagram of the processing device with the connected television cameras,

Fig. 2

the block diagram for handling the image information on the monitor side and

Fig. 3

Scheme for dividing a television picture into partial information.

A plurality of television cameras F1 to Fn are connected to the processing device VE shown in FIG. 1 and are permanently set to one or more objects to be monitored. The high-resolution image signals generated by the television cameras are simultaneously fed to 2 image converters BW 1 and BW 2. In the image converter BW 1, the image signals are converted to those for a low-resolution image display, but the image display still allows the object to be monitored to be clearly identified. The image converter BW 2 is used to convert the image signals into those for a higher-resolution display, which, however, is lower than that of the images recorded by the television cameras F.

The image information generated by the image converter BW 1 is stored in an image memory BSA and the image information of the image converter BW 2 is stored in an image memory BSB, in each case the information of an image for a predetermined time. In the idle position, ie when there is no alarm, the contents of the image memories BSA are read out cyclically and transmitted to the opposite side via the switching device UM and via the transmission line L. If the transmission line L has a transmission speed of 64 kb / s, for example, and partial information BT (see FIG. 3) of an image is transmitted with each frame (per second), the memory contents of all the image memories BSA can be transmitted after 16 s if A specific section is reserved in each frame for each image memory BSA. This is done by dividing each frame, for example of a length of 64 kbit, into subframes, each subframe being permanently assigned to an image memory BSA and serving for sub-information BT.

The memory content of the image memories BSA is also fed to a motion detection device BE. This also has image memories, not shown, in which the previously recorded image has been stored in each case. By comparing this picture with the picture taken at the moment, a movement can be clearly recognized if a difference occurs between the two pictures. As soon as a difference is recognized, the motion detection device BE generates a signal for the control device ST which indicates the television camera F which has taken the picture in which motion has been detected. Furthermore, the motion detection device BE generates a signal for the control device ST for a comparison device V, which also informs the latter about the television camera F in question and also about the part of the image in which the movement was detected. The comparison device V then calls up the information of the relevant image part from the high-resolution image memory BSB and compares it with the patterns of a pattern memory MS. The pattern memory MS contains the patterns in the form of various views of a large number of objects (for example impact drill, pistol, hammer, measuring device, etc.) in the form of corresponding image information. As soon as the comparator V uniquely identifies an object, the control device ST receives a corresponding signal from it and then causes the switching device UM to read the pattern determined during the comparison from the pattern memory and to transmit it to the transmission line L. It is also conceivable to additionally store a symbol for the object in question in the sample memory MS and to transmit this symbol to the remote station, for example in a low-resolution representation, if the identification is unambiguous via the transmission line L.

The remote station can now either send a corresponding request signal to the processing device VE or further automatically after a certain time after the transmission of the information from the pattern memory MS by the control device ST to cause the switching device UM to read out the image memory BSB with the high-resolution image information of the television camera in question, the total transmission capacity of the transmission line L then the transfer of the memory content is required. No image information is transmitted for the other television cameras during this time.
It is not absolutely necessary to provide two image converters BW and two image memories BS per television camera F. If the amount of information is sufficient for a sufficient resolution of the representation for comparison with the content of the sample memory MS, an image converter BW and an image memory BS per television camera F are also sufficient. In this case, after the relevant memory content of the sample memory MS has been transferred, the exclusive transfer of the content takes place of the relevant image memory BS. It is also conceivable, in the presence of two image memories (BSA, BSB), to use the content of the image memory BSB only for pattern recognition and to limit the transfer of the image information to the image memory with the image information for a low resolution of the representation.

In the event of an alarm, i.e. with a corresponding message from the motion detection device BE, a signal is sent to the remote station for triggering an optical and / or acoustic alarm signal at the instigation of the control device ST, an indication of the television camera F in question also being given, if appropriate.

The transmission line L ends in the remote station (see FIG. 2) in a distribution device VT, which distributes the nested transmitted partial information of the images to the associated buffer stores ZS, and controls the storage there at the location provided for this purpose. The buffers are cyclically overwritten with new information and are read out cyclically, the memory content being used for display on the respective monitor M. There are as many buffers ZS as there are monitors M1 to Mn, but the arrangement of a common monitor M is also conceivable, which is cyclically connected to a buffer ZS one after the other by a device (not shown).
In the idle state, the image information contained in the image memories BSA is transmitted interleaved one after the other via the transmission line L to the intermediate memories ZS. In the event of an alarm, ie when a movement is detected by the processing device VE (see FIG. 1), the image information of the determined pattern is first transmitted from the pattern memory MS to the monitor M assigned to the television camera F in question, and then the transmission line L for Transfer of the image information from the image memory BS used, which is assigned to that television camera F which recorded the movement. During this time, the content of the remaining buffers ZS is not updated, so that the previous image is shown on the monitors M.

In the event of an alarm, the processing device VE generates an alarm signal for the remote station, which results in an optical and / or acoustic alarm display. The corresponding alarm signals can be transmitted either via the transmission line L or via another transmission medium. The alarm display is triggered by an alarm generator AG, the person observing the monitors M being alerted by an acoustic signal and then the relevant monitor being optically identified. If there is only one common monitor M, an acoustic signal is sufficient.

The sample memory MS (FIG. 1) contains a large number of representations for each object in question, not only from different angles, but also in different sizes. Depending on the amount of data to be processed, either a successive comparison of the individual patterns or a simultaneous comparison with several patterns is now conceivable. If no object can be clearly identified within the scope of the detected movement, the processes proceed in the manner described without the transfer of a pattern or a symbol.

It is also conceivable to transfer only an identifier for the recognized symbol to the monitor M instead of the image information, it being possible, for example, to convert the transmitted identifier into a symbolic image representation or also into a plain text representation in the buffer memory ZS, the symbol or the plain text is shown on the screen of the monitor M. It is also conceivable in the event of an alarm to display the symbol or the plain text display and the transmitted (high-resolution) image information on a further monitor which is only used in the event of an alarm.

Claims (19)

1. Television monitoring system comprising at least a television camera, a processing device and at least one monitor for the reproduction of the pictures recorded by the television camera, the processing device being designed as an electronic motion detector, electronically monitoring the recorded pictures and generating an alarm message in the event of a picture change, characterized in that the processing device (VE) has a memory (MS) containing the picture information items of a multiplicity of target items, in that, in the event of an alarm message, that part of the recorded picture in which the change has taken place is compared with all of the target items in the target item memory (MS) by a comparison device (V), and in that in the event of correspondence with a target item, the picture information item thereof is read out from the target item memory (MS), transmitted to the monitor (M) and used there for the indication of the relevant target item.
2. Television monitoring system according to the preamble of Patent Claim 1, characterized in that a multiplicity of television cameras (F1 to Fn) are connected to the processing device (VE), in that the picture information items, recorded at regular time intervals, of a respective television camera are stored in a permanently assigned picture memory (BS), in that partial information items (BT) are cyclically read out from all of the picture memories (BS) and are transmitted in a nested manner via a narrowband transmission line (L) to a common monitor (M) which has a buffer (ZS) or to the respective monitor (M) which is permanently assigned to the relevant television camera (F) and has an individual buffer (ZS), in that the processing device (VE) has a memory (MS) containing the picture information items of a multiplicity of target items, in that, in the event of an alarm message, that part of the recorded picture of the relevant television camera (F) in which the change has taken place is compared with all of the target items in the memory (MS) by a comparison device (V), in that in the event of correspondence with a target item, the picture information item thereof is transmitted from the memory (MS) to the common monitor (M) or to the monitor (M) assigned to the relevant television camera (F) and is used there for the indication of the relevant target item, and in that subsequently, either automatically or at the request of the remote end, the picture information items of that picture memory (BS) whose television camera (F) has recorded the picture change are exclusively transmitted to the monitor (M) assigned to the relevant television camera (F).
3. Television monitoring system according to Claim 2, characterized in that the narrowband transmission line (L) is designed as a digital transmission line.
4. Television monitoring system according to either of Claims 2 and 3, characterized in that the transmission line (L) has a transmission rate of 64 kb/s per frame, each frame being subdivided into subframes of the same size in accordance with the number of television cameras (F1 to Fn), each subframe being permanently assigned to a television camera and being used for the transmission of a partial information item (BT) of a picture, with the result that the information items of a complete picture are transmitted after a specific time.
5. Television monitoring system according to one of Claims 1 to 4, characterized in that the alarm message is indicated acoustically at the monitor (M).
6. Television monitoring system according to one of Claims 2 to 4, characterized in that when there are a plurality of monitors (M), the alarm message is indicated optically and/or acoustically at the relevant monitor.
7. Television monitoring system according to either of Claims 1 and 2, characterized in that, in the quiescent state (no alarm message), the picture information items recorded by the television camera or cameras (F) are greatly compressed by the processing device (VE) for transmission to the monitor or to the monitors (M), and in that, in the event of an alarm, the picture information items of the relevant television camera are transmitted to the relevant monitor (M) for high-resolution display.
8. Television monitoring system according to one of Claims 1 to 7, characterized in that the processing device (VE) has two picture memories (BS) for each television camera (F), one picture memory (BSA) being used to store the picture information items for low-resolution display and the other picture memory (BSB) being used to store the picture information items for high-resolution display, and both picture memories (BSA, BSB) being written to simultaneously and in parallel.
9. Television monitoring system according to one of Claims 1 to 8, characterized in that the comparison of the contents of the target item memory (MS) with the contents of the picture memory (BSB) takes place for high-resolution display.
10. Television monitoring system according to one of Claims 1 to 9, characterized in that the target item memory (MS) has the models of a multiplicity of objects at different viewing angles and in different sizes.
11. Television monitoring system according to Claim 10, characterized in that the picture information items for the relevant symbol are stored in the target item memory (MS) for each object and, in the event of an alarm, the picture information items of the relevant symbol are transmitted to the monitor (M).
12. Television monitoring system according to one of Claims 1 to 11, characterized in that the picture information items of the symbols are stored in low-resolution representation in the target item memory (MS) and are transmitted to the monitor (M).
13. Television monitoring system according to Claim 2, characterized in that the pictures recorded by the television cameras (F1 to Fn) are successively shown, each for a specific time, on the common monitor (M), and in that the picture shown in the event of an alarm is the picture from that television camera (F) in which a movement has been identified.
14. Television monitoring system according to one of Claims 2 to 8, characterized in that, in the quiescent state, the picture information items are read out from the picture memory (BSA) for picture information items for low-resolution display and, in the event of an alarm, the picture information items are read out from the picture memory (BSB) for high-resolution display and are transmitted to the relevant monitor (M).
15. Television monitoring system according to Claim 1, characterized in that, instead of the picture information item, only an identifier for the symbol identified is transmitted to the monitor (M).
16. Television monitoring system according to Claim 15, characterized in that the transmitted identifier is converted in the buffer (ZS) into a symbolic picture information item for display on the monitor (M).
17. Television monitoring system according to one of Claims 1 to 16, characterized in that the transmitted identifier is converted in the buffer (ZS) into plain text for display on the monitor (M).
18. Television monitoring system according to either of Claims 1 and 2, characterized in that, in the event of an alarm, the picture information item is transmitted starting with low-resolution representation (subsampling).
19. Television monitoring system according to one of Claims 1 to 18, characterized in that the symbolic picture display and/or the display of the transmitted picture information item in the event of an alarm takes place in parallel on a further monitor (M).

Images