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US 2003/0193577 A1Published application
Multiple video camera surveillance system
AssigneeNone recorded
InventorsJorg Doring, Hartmut Sprave
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AssigneeNone recorded
InventorsJorg Doring, Hartmut Sprave
Estimating the term…
A video surveillance system comprises a plurality of video cameras (C1, C2, . . . , Ci) as well as a video signal switch (MUX), a means (SC) for controlling the video signal switch (MUX) and the video cameras (C1, C2, . . . , Ci) and a video signal recording means (VR). The video cameras (C1, C2, . . . , Ci) each comprise a pulse generating means (TC) for free-running generation of a sequence of horizontal and vertical synchronization pulses, and a means (SP) for combining the image and the sequence of horizontal and vertical synchronization pulses into a composite video signal. The pulse generating means (TC) assumes a predefined starting status on receiving an external reset pulse (R) and generates the sequence of the horizontal and vertical synchronization pulses commencing with the predefined starting status. The system controller (SC) comprises a clock generator (CLK, FD1, FD2) for generating a reset pulse for communicating it to the video cameras (C1, C2, . . . , Ci) in common. A video signal decoding circuit in the video signal recording means (VR) locks on to the horizontal synchronization pulses contained in the video signal so quickly that it is able to decode video signals comprising time distortions caused by the periods of the sequences generated by each camera deviating from the nominal period.
A video surveillance system comprising a plurality of video cameras (C1, C2, . . . , Ci) as well as a video signal switch (MUX)including a plurality of inputs (CV1, CV2, . . . , CVi) and at least one output (MO), a means (SC) for controlling the video signal switch (MUX) and said video cameras (C1, C2, . . . , Ci), a video signal recording means (VR) connected to said output (MO) of said video signal switch (MUX);
The video surveillance system as set forth in any of the preceding claims, characterized by a circuit for generating selection control signals, the circuit being configured to process the vertical synchronization information contained in said video signal (MO) furnished by said video signal switch (MUX) to generate said selection control signals for said video signal switch.
The video surveillance system as set forth in any of the preceding claims, characterized in that said clock generator is configured to derive said reset pulse from a time-variable component of a power supply voltage.
The video surveillance system as set forth in any of the preceding claims, characterized in that said video decoder circuit is configured to digitize the signal furnished by said video signal switch (MUX), to decode said digitized signal and to record it in digital form.
The video surveillance system as set forth in any of the preceding claims, characterized in that said video signal switch (MUX) is integrated in said video signal recording means.
The video surveillance system as set forth in any of the preceding claims, characterized by a means for generating a camera identification information and for inserting this information into said signal recorded by said video signal recording means.
The video surveillance system as set forth in any of the preceding claims, characterized in that said image signal contains a chroma component in addition to said luminance component;
The video surveillance system as set forth in any of the preceding claims, characterized in that each of said video cameras (C1, . . . , Ci) is connectable to its associated input of said video signal switch (MUX) via a fast Ethernet cable which communicates in addition to the video signal from said camera also the power supply voltage as well as said reset signal to said connected camera.
The video surveillance system as set forth in any of the preceding claims, characterized in that said video signal decoding circuit comprises;
The video surveillance system as set forth in any of the preceding claims, characterized in that said video decoding circuit is configured to work in a fast locking mode for extracting the horizontal synchronization.
The video surveillance system as set forth in any of the preceding claims, characterized in that
The video surveillance system as set forth in any of the preceding claims, characterized in that
The video surveillance system as set forth in any of the preceding claims, characterized in that said video signal recording means is configured to record said decoded video signal digitally on a video tape or on a hard disk, CD-ROM or DVD with or without data compression.
The video surveillance system as set forth in any of the preceding claims, characterized in that said clock generator (CLK, FD1, FD2) is configured
A video camera for use in a video surveillance system in accordance with any of the preceding claims, comprising an image converter (CCD) and a resettable timing circuit (TC) for controlling generation of a standardized video signal as well as an input (RT) for receiving an external reset signal (R).
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Backward citations are indexed for grants only.
Details of the system layout: multiple cameras having overlapping views on a single scene
Using television cameras: electrical details of the system, e.g. component blocks for carrying out specific functions
Involving the multiplexing of an additional signal and the video signal: the additional signal being at least another television signal
Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast: for receiving images from a plurality of remote…
Term end not estimated
The present invention relates to a multiple video camera surveillance system.
As a rule, such a surveillance system comprises a plurality of cameras, a means for switching or multiplexing the signals of each camera, and a recorder for recording the multiplexed video signals of the cameras. on a storage medium, for example, a magnetic tape or hard disk.
The element central to these systems is the multiplexer. It is this that first makes it possible to record the video signals of the individual cameras by a common recorder in time-multiplex. Multiplexing is a term designating a means which ensures that each camera connected can communicate with the recorder for a defined time interval so that the images of a plurality of cameras can be recorded alternately in sequence each with a reduced frame rate. To make available a plurality of channels for recording and playing back the images from the cameras, the multiplexer thus has the function of a switcher for switching from one camera to the next. In multiplexing video signals into a useful multiplexed signal, one needs to realize that the video signals furnished by the individual cameras comprise a relative complex format including, in addition to the actual image data, also synchronization data, as well as, where color signals are involved, so-called bursts for regenerating the color subcarrier.
The present invention will now be detailed by way of a preferred embodiment with reference to the attached drawings in which:
FIG. 1 is an overview block diagram of an example embodiment of the video surveillance system in accordance with the invention;
FIG. 2 is an example embodiment of a camera for the video surveillance system in accordance with the invention;
Referring now to FIG. 1, there is illustrated an overview block diagram of an example embodiment of the video surveillance system in accordance with the invention. In this Figure, C1, C2, . . . , Ci each designate a video camera as may be sited at various locations of a building, property or public facilities requiring surveillance as a visual security function. MUX designates an analog video multiplexer including a number of analog video inputs, one each being needed separate for each camera Ci to be connected to the multiplexer MUX. MO designates an output of the analog video multiplexer MUX on which the video signals are available at the input of the multiplexer in time-multiplex, meaning that each of the signals at the input of the multiplexer can be communicated one after the other for a specific time interval to the output whilst the remaining camera signals are not communicated to the output MO. The multiplexer MUX thus multiplexes the signals of the cameras C1 to Ci in the sense of providing at its output MO a cyclic sequence of signal sections from each of the cameras C1 to Ci. VR designates a video signal recording means which is connected to the output MO of the multiplexer MUX for recording the output signal of the multiplexer. SM designates a medium for storing the image data contained in the video signal available at the output MO. In the preferred embodiment as shown in FIG. 1, the storage medium SM is a hard disk serving to store the digitized decoded image data at the output of the multiplexer MUX following compression of this data by an image compression algorithm, for example in accordance with the JPEG standard or MPEG standard. Of course, instead of a hard disk, any other suitable storage medium can be used as storage medium. For example, the image data available at the output MO of the multiplexer MUX can be recorded on a suitable magnetic tape or an optical disk storage medium, e.g. a CD-ROM or DVD for once-only or multiple writing can be used to store the image data. Optical disk storage medium for once-only writing such as DVD-R, DVDandR, CD-R are particular of advantage for this purpose since they thwart subsequent manipulation of the stored data or at least are a tell-tale for such manipulation.
In the example embodiment as shown in FIG. 1, SC designates a system controller for controlling, on the one hand, the multiplyexer MUX and, on the other, furnishes a reset signal to the cameras C1, C2, . . . , Ci. R designates a cable from the system controller SC to an input on each camera C1, C2, . . . , Ci for receiving a reset signal.
MC designates in this example embodiment a plurality of binary control lines via which digital selection control signals can be communicated to the multiplexer MUX as generated by the system controller SC. These selection control signals communicated via the selection lines MC to the multiplexer MUX dicatate which of the inputs of the multiplexer, and accordingly, which of the video signals CV1, CV2, . . . , CVi generated by the video cameras is to be communicated to the output MO of the multiplexer MUX. Although a parallel signal format is illustrated for these selection control signals, it is, of course, just as possible as an alternative to communicate the selection control data to the multiplexer MUX serially.