FR2841421A1 - Video surveillance signal transmission mechanism with detector/camera remotely transmitting digital images acquired and processing unit processing digital words received - Google Patents

Abstract

The signal transmission mechanism (10) has a detector or camera (11) for acquisition. There is a digital word processing unit (UT) processing the digital words received from the camera and a radio receiver (16) to remotely transmit the digital images acquired.

Description

of the emitting terminal.

2841 421

  Method and device for remote transmission of signals, images and data The present invention relates to transmission methods and devices

  distance of signals, images and / or data.

  The technical field of the invention is that of video surveillance. It is known to equip buildings with several observation cameras of areas to be monitored, in particular areas of access (entry eVou exit) to the building; the signals delivered by each camera generally transmitted to a display device of the images acquired by these cameras, which may include a television monitor; the signal transmission can be obtained by wires or cables

  connecting each camera to the display device.

  When one wishes to equip several buildings or constructions of a system of video surveillance common to all the buildings, the laying of cables intended to allow the transmission of the cameras of the cameras to a centralized control position, often needs to dig trenches in which wind buried the cables; such wind operations are all the more costly as the wind buildings

away from each other.

  When video surveillance cameras partly observe a public place and partly a private place, it is sometimes necessary to mask part of each image delivered by this camera, in order to respect the right to a private life of human beings. The presence of surveillance cameras in public or private places is difficult to hide; as a result, these cameras are sometimes subject to vandalism; in order to reduce the cost of repair resulting from such acts, some CCTV installations are equipped on the one hand with real cameras actually connected to a display and control position, and on the other hand with lures imitating the appearance of a camera without having the features; the presence of such viruses is supposed to reduce acts of incivility on the part of individuals who believe - wrongly - to be in the field of observation of a real surveillance camera; The interest of such decoys diminishes over time, since on the one hand the curiosity and learning abilities of certain human beings

2841 421

  distinguish a lure from a real camera, and secondly the communication capabilities of these human beings with other individuals quickly allows these

  to be informed of the perch.

  The replacement of a decoy by a real camera (and vice versa), and the connection of the camera moved to centralized control position, require the corresponding modification of the wiring connecting the camera to this posse; these

  long and expensive wind changes.

  When it is desired to remotely transmit images delivered by a surveillance camera, it is possible to use for this purpose a telecommunication network, in particular a switched telephone network; however, the limited ability of terminal links in public networks greatly limits the "refreshing" frequency of images transmitted in this way (eVou their definition); furthermore, the cost of telecommunications does not permit the permanent use (24 hours a day) of this type of connection; the establishment of wireless links at high speed between a camera and a surveillance position leads to costs

even higher.

  CCTV inside terrestrial means of transport poses additional problems because of the mobility of the camera installed

board of a transport vehicle.

  It is known to equip buses with an observation camera and a system for recording images delivered by the camera on a recording medium; such a system makes it possible to visualize, by a reading of recording medium, but

  only later, the images acquired by the camera.

  An object of the invention is to propose a system (method and device) for

  Videosu rvei l lance whose installation and installation costs are redu cted.

  One objective of the invention is to propose a transmission system

  distance of signals, eVou data, high speed and low cost images.

  One objective of the invention is to propose a video surveillance system in

  real time on board a transport vehicle.

2841 421

  An object of the invention is to provide a remote video surveillance system which is improved and which remedies - at least in part - the disadvantages of

known systems.

  According to a first aspect, the invention consists of a method for monitoring a zone, in which the zone to be monitored is equipped with a device comprising a sensor for acquiring signals, in particular a camera for acquiring data. images of the zone, a data processing unit (UT) connected to the sensor or camera so as to receive the signals or images delivered by the latter, as well as a transceiver radio (ER) relies on the unit (UT) to receive from the UT the said signals or images in digital form, and to emit radio waves incorporating digital data corresponding to the signals or images digitized; ) s. The presence of the ER confers on the device the ability to remotely receive operating data that is processed by the UT to adapt, based on these data, the image acquisition parameters and those of the remote transmission.

acquired images.

  Preferably, the UT comprises means of encrypting the data corresponding to the images delivered by the camera, and comprises data compression means corresponding to the images delivered by the camera; the data encryption means make it possible to ensure the confidentiality of the encrypted data transmitted by radio; the data compression means makes it possible to remotely transmit digitized and compressed images having a good resolution, at a high frequency; preferably, images having a definition ranging from 105 pixels to at least 106 pixels - e.g., images having a definition of 640 x 480 pixels - are scanned, with an acquisition frequency - and generally radio transmission ranging from 1 Hz to 100 Hz, in particular ranging from 5 Hz to 50 Hz, for example of the order of 25 Hz; in order to transmit the corresponding data in real time, so as to be able to display them without delay and continuously, a radio data transmission system having a sufficient flow rate is used; preferably one uses a system whose rate - or transfer rate - is at least equal to 1 Mbps (Megabit per second), in

  particular is in the range of 1 to 11 or 54 Mbps.

  To compress the data, compression techniques whose compression ratio is close to 10 or greater than 10 are preferably used, in particular compression algorithms in the MPEG2 format, or more preferably MPEG4, which make it possible to compress the images. with a rate in a range from 10 to 100. Preferably and according to another aspect of the invention, the transmission of scanned and compressed images between a monitoring device as defined above and a monitoring position is carried out, at least in part by a local wireless data network (hereinafter referred to as "the first network"), which has a mesh network topology in which stations in the network communicate directly with each other in the network. a point-to-point operating mode (<< ad-hoc> mode); preferably, the transmission is carried out according to the IEEE 802.11 standard which allows a transmission rate of 1 or 2 Mbps at least, in particular according to the 802.11b standard which allows a transmission rate of about 11 Mbps maximum; this standard also makes it possible to carry out wireless transmissions according to a

  hierarchical mode between a station and an access point.

  The use of such a mesh network allows each monitoring device integrated in the network to have a large and permanent available flow at a reduced cost; this further facilitates the adaptation of the monitoring system, in particular for the connection to the network of an additional monitoring device, as well as in the case where a video surveillance device forming part of the network is replacing

  - temporarily at least - by a lure.

  The use of such a network also facilitates the transmission of signals, data and digital images issued by a surveillance device on board.

  board of a vehicle - including public transport -.

  In this particular use, the invention also proposes to equip such a vehicle with a monitoring device defined hereinbefore, which furthermore comprises a second radio transceiver capable of transmitting signals, digitalized images. compresses (e) eVou give, by a second bidirectional transmission network and, preferably, detection means for detecting the presence, near the vehicle, of a station of the first network, and means for stopping the transmission by the second network in favor of a transmission by the first network when such a presence is detected; these detection means

2841 421

  s may be at least partly implemented in software form in the UT of

device embeds.

  When the second network is a GSM cellular network, the transmission of the images delivered by the on-board camera can then be performed using the packet data transmission service GPRS, when the vehicle is located beyond the reach of a station ( fixed or mobile) of the first network; when the second network is a UMTS or CDMA network, the images or signals

  compresses wind also transmitted in packets.

  Given that the useful transfer rate of the second network is generally lower than that of the first network, the latter is used primarily

  thanks to the presence of said detection means.

  The onboard monitoring device preferably further comprises means for recording and storing the image data scanned and compressed on a support; thus, in a continuous surveillance degraded mode in which the first network is not accessible to the vehicle and in which the flow of the second network does not allow the transmission of the images delivered by the camera to the desired image acquisition frequency, a first part of the corresponding data can be routed through the second network, while one; at least second part of the data is recorded on an embedded data storage medium such as a magnetic eVou optical disk; a medium whose storage capacity makes it possible to record all the images acquired at the desired frequency, after compression of these data, during a period of time, is preferably selected

a duration of several hours.

  Preferably, the UT of a device - fixed or mobile - CCTV according to the invention comprises masking means for applying a mask to an image delivered by the camera connected to the UT, before recording on a data carrier eVo transmit it to a remote surveillance posse of the device; thanks to the connection between the UT and the ER (of said first eVou second network), masking data relating to the form of a given mask can be sent from a remote monitoring position, by radio transmission, transmitted by the ER to the UT, then saved in a memory of the device eVou of the UT; this makes it easy to adapt and modify the masking means, at a distance,

2841 421

  especially when the surveillance device is moved from a first zone a

  watch at a second area to be monitored separately from the first.

  The transmission of data according to the 802.11 (b) standard makes it possible to use the TCP / IP transmission protocol and thus facilitates the use of the data transmitted by the first network according to this protocol by numerous communications management software. Despite the small range (a few hundred meters) of ERs complying with 802.11, it is possible to form a network with adequate coverage

  when the density of stations is - temporarily at least sufficient.

  According to another aspect, the invention proposes a mobile monitoring device such as that defined above, which comprises means (auto) location to know the position of the device and transmit it to the surveillance position; for this purpose, the vehicle on which the surveillance device is carried may comprise a GPS receiver connected to the UT; alternatively, the position of the vehicle can be determined by triangulation using the first eVou the second network of

transmission of data by radio.

  The use of a high-speed radio transmission and the presence of the UT further enable transmission to the on-board surveillance device, eVou images and digital sounds with advertising character; alternatively, the images and advertising sounds are recorded on a laughable data carrier by the UT; it is thus possible to present to the personnel transported by a vehicle equipped with the device, on a screen relic to the UT, images or advertising spots which can for example be chosen according to the position of the vehicle, in order to promote an establishment located nearby. of it; for this purpose, the reading eVou the display is controlled according to position data that can be issued to the UT by the GPS receiver, or that are determined by software means integrated UT. Other advantages and features of the invention will be understood through

  of the following description which refers to the accompanying drawings, which illustrate without any

  limiting character of the preferred embodiments of the invention.

  Figure 1 schematically illustrates the main components of a device

  stand-alone surveillance system on board a vehicle.

  Figure 2 schematically illustrates the main components of a station

centralized control.

  Figure 3 schematically illustrates the application of the invention to monitoring

  premises and vehicles in urban areas.

  Figure 4 schematically illustrates the main components of a station

  fixed surveillance connected to the high speed mesh network.

  With reference to FIGS. 1 and 4, the video surveillance device 10 comprises a data processing unit UT consisting essentially of a microprocessor card of the PC industrial type, for example in PC 104 format; this unit operates under the control of software comprising a program 12 for detecting a station of the high-speed mesh network, a program 13 for masking images,

  and a program 14 for compressing and encrypting digital sounds and scenes.

  The UT is connected by a link to a camera 11 delivering UT images in digital or analog form; in the latter case, the UT integrates (or is interfaced with) a digital analog converter; the fixed (FIG. 4) and mobile (FIG. 1) devices furthermore comprise a transceiver 16 equipped with an antenna 18 and connected to the UT via a link 17, so as to allow radio transmission by the first mesh network compressed digital images issued to the transmitter 16 by the UT, according to the 802.11b standard and the TCP / IP protocol; this transmission intended for a central surveillance position may be, as described below, relayed by a network access point - in hierarchical mode - or by another station of the first

network - in << ad-hoc >> mode.

  Under the control of a program 19, the UT can ensure that the IP standard of the data to be transmitted, the management of the incoming and outgoing data flows and the switching of the transmission of data, from the first to the second network, and vice versa, are provided. . In the case of the embarkable device shown in FIG. 1, a GSM receiver transmitter module 20, which is connected to the UT by a link 21, ensures that transmission of a portion of the data delivered by the camera 11, in particular, is carried out, if necessary.

2841 421

  when no station or point of access to the first network is located near the

  vehicle equipped with the monitoring device.

  The embeddable device 10 FIG. 1 comprises an input device 22 such as a microphone, a sensor or other input terminal such as a keyboard, as well as a screen 23 for viewing advertising images transmitted by a central station. the network via the first network, the ER 16 and the UT; these peripherals wind connected to

  the UT by respective links 24, 25 for this purpose.

  The device 10 further comprises a device 26 for reading and writing digital images compressed on a magnetic medium, of the "disk" type.

  hard >>, as well as a GPS receiver 60.

  As schematically illustrated in FIG. 1, the UT, the camera, the ER 16 and the unit 26

  recording at least wind powered by a battery 27.

  With reference to FIG. 2, the device 30 integrated in the centralizing control position comprises a data processing unit 31 equipped with a bidirectional radio link card 32 with stations of the first network comprising an antenna 33; this equipment is identical or similar to UT components, 16 and 18

Figures 1 and 4.

  The device 30 further comprises a display screen 34, a link interface - wired or nan-wired - with access points of the first network, and an interface 36 - such as a switch - connection to the second network.

  public network of telecommunication.

  In the case where the control unit is located at a distance from the first network and does not serve as an access point, the radio link card 32 is deleted, the device being connected to the first network by the interface 35 and a link bidirectional such

that spotted 43, 44 figure 3.

  With reference to FIG. 3, the first network - or private network - comprises three access points 40 to 42 which are fixed and connected together by two bidirectional links 43, 44; each access point 40 to 42 may be equipped with the device 30 shown in Figure 2; alternatively one or two access points among the trots may be equipped with a device 10 illustrated in Figure 4, or a similar device but

  camera noise in the case of a simple transmission relay.

2841 421

  Each of the links 43 and 44 may be a link link, a radio link,

  an optical fiber connection or a laser optical link tip.

  Around each access point extends a cell 45 to 47 whose shape and extent depends on the range of the radio ER equipping the access point and the corresponding stations; it is evident from this figure that the cells are disjointed. Inside each cell are trots or four stations 48 of the first network, each of which is represented by a square; each station can transmit data to another station which is accessible to it - from the same cell - in ad-hoc mode and can also transmit data to the access point.

hierarchize mode -.

  Each station may be equipped with the device 10 illustrated in FIG.

  The network also has five mobile monitoring stations 49 to 53

  respectively boarded five public transport vehicles.

  These vehicles travel along the curvilinear section 54 extending between two terminals 55 and 56; starting from this terminal 56, a vehicle passes through a portion of the cell 47 by transmitting compressed digital images to the central monitoring position 40, via the link 44, the access point 42 and where appropriate a s4ations 48 of this cell; between the exit of the vehicle from the cell 47 and the entry of this vehicle into the cell 46, the onboard device which it comprises transmits a part of the signals eVou surveillance data by a GPRS service of a GSM network not represented, until at posse 40, and records at the same time all the signals and / or surveillance data on a hard disk

equiping the device embeds.

  When a vehicle equipped with a device according to the invention (such as 53), circulates near another equipped vehicle (such as 52), their associated transmission devices can serve as transmission relay of the first network, so that if the vehicle density traveling on the line 54 is sufficient, the area 57 delimited by the dots extending on either side of the line 54 is part of the area covered by the first network, and relic the cells associated with access points. In this case, the use of the second network can be carried out only in case of failure of one of the

  stations or a point of access to the first network.

  If this density is not sufficient, the vehicle entering the cell 46 switches from the transmission mode using the GSM network, to a full, continuous transmission mode and in real time, that it remains within cell 46; a new change occurs when it leaves the cell 46, then again when it enters the cell 45, and finally when it comes out of it for

reach the terminal 55.

- :. -.

Claims (17)

  1. Apparatus (10) for transmitting signals, eVou images data, which comprises a sensor or a camera (11) for ['acquisition of signals or images, characterized in that it comprises a unit (UT ) of data processing linked to the   sensor or the camera to receive the signals or images, and an emitter-   radio receiver (16) relic to ['unite (UT) for remotely transmitting the signals or images acquired (s) digitized.   2. Device according to claim 1, which further comprises means (14) of   encryption of the digitized signals or images.   3. Device according to claim 1 or 2, which further comprises means (14)   compression of signals or digital images.   4. Device according to any one of claims 1 to 3, which comprises in   in addition to means (13) for masking the scanned images.   5. Device according to any one of claims 1 to 4, which comprises in   in addition to means (12) for the proximity detection of a radio transceiver which, together with the transceiver (16), is part of a first transmission mesh network,   data whose bit rate is at least 1 Mbps.   6. Device according to any one of claims 1 to 5, which comprises in   in addition to a second radio transceiver (20) able to communicate with a   second cellular network for packet data transmission.   7. Device according to claims 5 and 6, which further comprises means   (19) switching the transmission of data, from the first network to the second network or vice versa, based on detection data produced by the means (12) of detection.   8. Device according to any one of claims 1 to 7, which comprises in   in addition to means (26) for recording signals or images digitized on a data support.   9. Device according to claim 8, wherein the capacity of the data medium makes it possible to record at least 105 images having a definition at least   equal to 105 pixels, especially at least 106 images.   10. Device according to any one of claims 1 to 9 which comprises in   in addition to a display (23) which is connected to ['unit (UT) for viewing images transmitted by the transceiver (16) according to position data of the device.   11. A transport vehicle comprising a device according to any one of   1 to 10, and wherein the unit (UT) is preferably connected to a   GPS receiver for remotely transmitting the position of the vehicle.   12. CCTV system comprising a plurality of devices according to one   any of claims 1 to 10.   13. Method of transmitting signals, images eVou data in which one   uses a device according to any one of claims 1 to 10 for transmitting   remote signals or images digitized at a frequency in a   range from 1 to 100 Hz, in particular from 5 to 50 Hz.   14. Method of transmitting signals, images eVou data in which one   i - uses a device according to any one of claims 1 to 10 for transmitting   remote from the digitized signals or images, by a wireless data transmission network, which has a mesh network topology in which stations (48) of the network communicate directly with each other in a wireless communication mode. point-to-point operation.   15. Method of transmitting signals, images eVou data in which one   uses a device according to any one of claims 1 to 10 for transmitting   remote signals eVou images scanned, according to the TCP / IP protocol.   16. A method for monitoring a zone, in which the zone to be monitored is equipped with a device (10) comprising a camera (11) for acquiring images of the zone, a data processing unit (UT). ) connected to the camera in order to receive the images issued by them, have a radio receiver (ER) relic to the unit (UT) so as to receive These images in digital form, and has emitted radio waves incorporating digital data corresponding to each of the scanned images.   17. Method according to claim 16 for surveillance in a vehicle, in which signals and / or images digitized (s) compressed by a first network are transmitted remotely, continuously and at a high frequency. wireless data transmission system, which has a mesh network topology in which stations in the network communicate directly with each other in a point-to-point mode of operation when the vehicle is near a station of the first network, and transmitting only a part of the signals or images digitized (s) compressed by a second public wireless transmission network when the