GB2362284A - Multiplexing and encoding images from muliple surveillance cameras - Google Patents
Multiplexing and encoding images from muliple surveillance cameras Download PDFInfo
- Publication number
- GB2362284A GB2362284A GB0011374A GB0011374A GB2362284A GB 2362284 A GB2362284 A GB 2362284A GB 0011374 A GB0011374 A GB 0011374A GB 0011374 A GB0011374 A GB 0011374A GB 2362284 A GB2362284 A GB 2362284A
- Authority
- GB
- United Kingdom
- Prior art keywords
- image stream
- multiplexed
- camera
- encoded
- streams
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
- H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
- H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
- H04N21/434—Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream
- H04N21/4347—Demultiplexing of several video streams
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T9/00—Image coding
- G06T9/004—Predictors, e.g. intraframe, interframe coding
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/18—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength
- G08B13/189—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems
- G08B13/194—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using image scanning and comparing systems
- G08B13/196—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using image scanning and comparing systems using television cameras
- G08B13/19639—Details of the system layout
- G08B13/19645—Multiple cameras, each having view on one of a plurality of scenes, e.g. multiple cameras for multi-room surveillance or for tracking an object by view hand-over
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/18—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength
- G08B13/189—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems
- G08B13/194—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using image scanning and comparing systems
- G08B13/196—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using image scanning and comparing systems using television cameras
- G08B13/19665—Details related to the storage of video surveillance data
- G08B13/19667—Details realated to data compression, encryption or encoding, e.g. resolution modes for reducing data volume to lower transmission bandwidth or memory requirements
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/18—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength
- G08B13/189—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems
- G08B13/194—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using image scanning and comparing systems
- G08B13/196—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using image scanning and comparing systems using television cameras
- G08B13/19678—User interface
- G08B13/19691—Signalling events for better perception by user, e.g. indicating alarms by making display brighter, adding text, creating a sound
- G08B13/19693—Signalling events for better perception by user, e.g. indicating alarms by making display brighter, adding text, creating a sound using multiple video sources viewed on a single or compound screen
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
- H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
- H04N21/21—Server components or server architectures
- H04N21/218—Source of audio or video content, e.g. local disk arrays
- H04N21/2187—Live feed
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
- H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
- H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
- H04N21/236—Assembling of a multiplex stream, e.g. transport stream, by combining a video stream with other content or additional data, e.g. inserting a URL [Uniform Resource Locator] into a video stream, multiplexing software data into a video stream; Remultiplexing of multiplex streams; Insertion of stuffing bits into the multiplex stream, e.g. to obtain a constant bit-rate; Assembling of a packetised elementary stream
- H04N21/2365—Multiplexing of several video streams
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/18—Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
- H04N7/181—Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast for receiving images from a plurality of remote sources
Abstract
Live images from a plurality of surveillance cameras 10 are encoded for transmission over a transmission link 20 to a remote display apparatus 30, where the transmission link 20 has limited bandwidth. The camera image streams are multiplexed to provide a multiplexed image stream in a multiplexer (14), and then predictive coded in a predictive coding unit (24) to provide a single encoded image stream such as using MPEG2. Ideally, each GOP in the encoded image stream (25) takes images from one of the cameras 10. The encoded image stream (25) reduces bandwidth requirements of multiple live image streams. Preferably, the images are time division multiplexed.
Description
2362284 Method and Apparatus for Encoding and Transmission of Images from
Multiple Surveillance Cameras The present invention relates in general to a method and apparatus for the transmission of live images from a plurality of surveillance cameras, and more particularly to a method and apparatus using a predictive coding scheme such as MPEG.
In a typical surveillance system, it is desired to record images for reproduction later, and it is commonly desired to display live images for immediate viewing by a user. often, it is desired to transmit images across a transmission link such as a local area network (LAN) or a is digital subscriber line of a public switched telephone network (PSTN). A problem arises in that, when a surveillance system employs a plurality of surveillance cameras, the bandwidth of the transmission link is limited and commonly cannot support the simultaneous transmission of live images from each camera. Further, whilst efficient predictive coding schemes such as MPEG are available for use with a stream of images from a single source, such predictive coding schemes are relatively inefficient where the image field changes frequently and so are not suitable for use in the live transmission of images from a plurality of cameras.
An aim of the present invention is to address the problems of the prior art discussed above or otherwise.
one preferred aim of the present invention is to provide a method and apparatus for the transmission of live images from a plurality of surveillance cameras. other aims of the invention relate to a method and apparatus for 2 efficiently encoding live images from a plurality of surveillance cameras, and to a method and apparatus for decoding and displaying the encoded images.
According to a first aspect of the present invention there is provided a method for encoding images from a plurality of surveillance cameras, the method comprising the steps of: (a) providing a camera image stream from each of a plurality of surveillance cameras; (b) multiplexing the camera image streams to provide a multiplexed image stream; and (c) predictive coding the multiplexed image stream to provide an encoded image stream.
Preferably, the camera image stream from each surveillance camera comprises independent still image frames, preferably in a logical sequence such as a temporal sequence. Preferably, the image stream from each camera is a live sequence of image frames at a predetermined frame rate. Preferably, the step (a) includes analogue to digital conversion of images produced by an analogue surveillance camera.
Preferably, the step (b) comprises time division multiplexing of the camera image streams. Preferably, the camera image streams are multiplexed based upon units of a predetermined number of image frames from each camera image stream. In one preferred embodiment, each unit comprises of the order of ten or twelve images in sequence from one camera image stream. Preferably, the multiplexing step (b) includes storing the plurality of camera image streams in a temporary storage, for ease of manipulation and to provide an accurate temporal record.
3 In some preferred embodiments of the present invention, the method includes the step (bi) of compressing at least one and preferably all of the independent still image frames using a non-predictive coding scheme, such as JPEG. Suitably, the non-predictive coding step is performed immediately before or immediately after the multiplexing step (b).
Preferably, the predictive coding step (c) takes the multiplexed image stream to form a continuous encoded image stream. In a preferred embodiment of the invention, the predictive coding scheme forms a group of pictures (GOP) comprising a sequence of independent still image frames taken from one of the cameras. Pref erably, each GOP comprises the same number of image frames as each unit in the multiplexing step (b). Alternatively, each unit forms more than one GOP. Suitably, each GOP is an individual GOP, comprising images from only one camera, taken from a corresponding portion of the multiplexed image stream. Preferably, the predictive coding step (c) produces an encoded image stream comprising a continuous stream of individual GOPs provided from the multiplexed image stream as if taken from a single source.
Preferably, the method comprises the step of (d) transmitting the encoded image stream over a transmission link. Conveniently, the transmission link is a local area network such as an Ethernet 10baseT or 100baseT network.
Alternatively, the encoded image stream is transmitted to a storage device.
4 Also according to the present invention there is provided a method for transmitting images from a plurality of surveillance cameras, the images being encoded according to the encoding method defined above, the S transmission method comprising the step of (d) transmitting the encoded image stream over a transmission link.
Further according to the present invention there is provided a method for decoding an encoded image stream that has been encoded according to the encoding method defined above.
In a first preferred embodiment, the method for decoding comprises the steps of: (e) receiving the encoded image stream; (f) predictive decoding the encoded image stream to reproduce the multiplexed image stream; and (g) demultiplexing the multiplexed image stream to reproduce the plurality of camera image streams.
In this embodiment, the encoded image stream is decoded using one corresponding decoder such as an MPEG software decoder in order to recreate the multiplexed image stream.
In a second preferred embodiment, the method comprises the steps of: (e) receiving the encoded image stream; (f') demultiplexing the encoded image stream to provide a plurality of demultiplexed image streams; and (g') predictive decoding each demultiplexed image stream to reproduce the original camera image streams.
Pref erably, the demultiplexing step (f is perf ormed based upon individual GOPs in the encoded image Stream.
Preferably, the predictive decoding step (gl) is performed using a separate software decoder for each demultiplexed encoded image stream.
It is preferred that the method comprises the step of (h) selectively displaying at least one of the camera image streams. Preferably, a continuous sequence of images from each camera image stream is displayed, for example, on a separate display device, or in a separate area of a single display screen.
Also according to the first aspect of the present is invention there is provided a method for transmitting live images from a plurality of surveillance cameras for display on a display unit, the method comprising the steps of: (a) providing a camera image stream from each of a plurality of surveillance cameras; (b) multiplexing the camera image streams to provide a multiplexed image stream; (c) predictive coding the multiplexed image stream to provide an encoded image stream; (d) transmitting the encoded image stream over a transmission link; (e) receivin.g the encoded image stream; (f) predictive decoding the encoded image stream to reproduce the multiplexed image stream; (g) demultiplexing the multiplexed image stream to reproduce at least one of the plurality of camera image streams for display on a display unit.
Further according to the first aspect of the present invention there is provided a method for transmitting live images from a plurality of surveillance cameras for 6 display on a display unit, the method comprising the steps of: (a) providing a camera image stream f rom each of a plurality of surveillance cameras; (b) multiplexing the camera image streams to provide a multiplexed image stream; (c) predictive coding the multiplexed image stream to provide an encoded image stream; (d) transmitting the encoded image stream over a transmission link; (e) receiving the encoded image stream; (f 1) demultiplexing the encoded image stream to provide a plurality of demultiplexed image streams; and (g') predictive decoding at least one of the demultiplexed image streams to reproduce a respective one of the camera image streams for display on a display unit.
According to a second aspect of the present invention there is provided an encoding apparatus for performing steps (a),(b) and (c) of the method defined herein.
Also according to the second aspect of the present invention there is provided an apparatus for encoding images from a plurality of surveillance cameras, comprising: a multiplexing unit for multiplexing a camera image stream from each surveillance camera to produce a multiplexed image stream; and a predictive coding unit for predictive coding the multiplexed image stream to form an encoded image stream.
Preferably, the multiplexing unit performs the multiplexing step (b) of the method discussed above.
Preferably, the predictive coding unit performs the predictive coding step (c) of the method discussed above.
7 According to a third aspect of the present invention there is provided a decoding apparatus for performing the steps (e) (f) and (g) of the method defined herein, or steps (e), (f') and (g') of the method defined herein.
Also according to the third aspect of the present invention there is provided an apparatus for decoding, comprising: a predictive decoding unit for predictive decoding the encoded image stream to reproduce a multiplexed image stream; and a display processing unit for controlling display of the multiplexed image stream on a display unit.
Preferably, the display processing unit includes a demultiplexing unit for demultiplexing the multiplexed image stream to reproduce the original camera image streams. Further, the display processing unit preferably controls a display unit to display each camera image stream as a separate continuous sequence of live images.
Also according to the third aspect of the present invention there is provided an apparatus for decoding, comprising: a demultiplexing unit for demultiplexing an encoded image stream to produce a plurality of predictive coded camera image streams; and a plurality of predictive decoding units, each for predictive decoding one of the plurality of predictive coded camera image streams to reproduce a camera image stream for display on a display unit.
For a better understanding of the invention, and to show how embodiments of the same may be carried into 8 effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which:
Figure 1 is a schematic overview of a surveillance system employing a multiple-camera image transmission method and apparatus of a preferred embodiment of the present invention; Figure 2 is a schematic illustration of image streams employed in a preferred embodiment of the invention; Figure 3 is a schematic diagram of a first preferred receiver apparatus; and is Figure 4 is a schematic diagram of a second preferred receiver apparatus.
Referring to Figure 1, the surveillance system 1 of the preferred embodiment is particularly intended for use in transmitting live images from a plurality of cameras 10 over a transmission link 20 to a remote display apparatus 30. The transmission link 20 may take any suitable form including, for example, an analogue transmission line such as a telephone line, a digital transmission line such as a digital subscriber line of a PSTN, or a dedicated transmission link such as optical cables. The preferred embodiment of the present invention is particularly intended for use with a transmission link such as a local area network (LAN) or wide area network (WAN) using transmission equipment following, for example, Ethernet 10baseT or 100baseT standards. Such a transmission link may well be employed for a variety of uses other than the surveillance system, and the total available bandwidth 9 must be shared accordingly. Hence, it is desired to minimise bandwidth associated with the transmission of images from the plurality of cameras 10.
In one practical example, the cameras 10 are positioned at suitable locations around an industrial plant such as a chemical processing facility and the images relayed to a display area for monitoring by users supervising operations of the plant. In this example situation, it is desired to provide live image streams from each camera with a relatively short delay, such that a user is able to monitor and respond immediately to the displayed images. Ideally, live images are displayed with a delay over the transmission link being of the order of only a fraction of a second.
Typically, each camera 10 produces a temporal sequence of still images such as twenty five frames per second and each frame may contain, for example, 20Kb of image data.
That is, each camera 10 typically produces an image stream containing around 0.5Mb of data per second. The surveillance system of the preferred embodiment of the invention employs between eight and sixty-four cameras, giving a full data rate of up to 32Mb per second.
2S Therefore, the data rates required to simultaneously transmit live image streams from each of a plurality of cameras exceeds the bandwidth capability of most commonly available transmission links and/or has a significant impact on other traffic that may need to use the same transmission link. Hence, it is desired to transmit live image streams from a plurality of cameras in a manner which is both timely and bandwidth efficient.
Referring to Figure 1, each of a plurality of cameras 10 produces a sequence of still images at a desired frame rate in a continuous camera image stream 13. A multiplexer 14 multiplexes the camera image streams 13 to produce a multiplexed image stream 15. The multiplexed image stream 15 is supplied to a predictive coding unit 24 which performs predictive coding using, for example, MPEG2, to produce an encoded image stream 25 for transmission over the transmission link 20.
In the preferred embodiment of the invention, each of the cameras 10 is conveniently an analogue image capture device producing a live image stream 11. Each camera is coupled to a video decoder 12 for producing a sequence of still images at the desired frame rate in a continuous camera image stream 13, including appropriate analogue to digital conversion.
The multiplexer 14 performs time division multiplexing based upon units of frames from each camera image stream 13. Each unit comprises a predetermined plurality of still image frames. In one preferred embodiment, each unit comprises of the order of ten or twelve frames.
A non-predictive coding unit 16 optionally performs non-predictive coding of each frame in the camera image streams, or preferably in the multiplexed image stream 15 as illustrated, using any suitable non-predictive coding scheme such as JPEG or MJPEG. The non-predictive coding unit 16 reduces the data required to represent each still image frame within the relevant image stream, but operates on each frame individually without any reference to the content of neighbouring frames.
A controller 22 supplies the multiplexed image stream 15 to the predictive coding unit 24, such that the predictive coding unit 24 operates on a single stream of 5 input data as if received from a single source. Conveniently, the camera image streams and/or the multiplexed image stream 15 are written to a storage 18, suitably fast disk storage depending upon the capacity required. This stored data is marked with temporal information to provide an accurate record of the images produced from the cameras. The stored data is then ready for use in later reproduction, such as for security and analysis purposes, where the problems associated with live transmission are not encountered.
The predictive coding unit 24 performs predictive coding using any suitable predictive coding scheme. In the preferred embodiment MPEG2 is employed. The predictive coding unit 24 produces an encoded image stream 25 comprising groups of pictures (GOPs) each produced from a plurality of still image frames. In the predictive coding scheme, each frame is encoded with reference to the content of neighbouring frames. Suitably, the predictive coding unit 24 forms each GOP corresponding to one unit of image frames in the multiplexed image stream 15. There is inevitably a data overhead at the boundary between each GOP. However, the preferred predictive coding scheme is ef f icient within each GOP itself because the images in each GOP are taken from the same camera image stream and therefore in most cases have a high degree of redundancy between frames. Suitably, under the preferred MPEG2 coding scheme each GOP is marked as an individual GOP to indicate that each GOP has a different image context.
12 In an alternate embodiment, a set of GOPs is used to represent one unit of image frames, all taken from the same camera. Here, at least the f irst GOP in each set is identified as an individual GOP to show the change of context between camera image streams.
Figure 2 illustrates example camera image streams 13, a multiplexed image stream 15 and an encoded image stream 25. The camera image streams 13 each contain a plurality of still image frames, taken in a sequence by one camera. The frames from the first camera are referenced 11111, the second camera 12", and so on up to the last camera 'In". The multiplexed image stream 15 contains units of frames from each camera, and in this simple illustrated example each unit contains four frames. In the preferred embodiment, the camera image streams are multiplexed by taking at least one unit of frames from each camera in sequence. However, any suitable multiplexing scheme may be employed. The encoded image stream 25 illustrated in Figure 2 contains one GOP corresponding to each unit, again in a repetitive sequence. The encoded image stream is.ready for transmission over the transmission link 20 using any suitable protocol. This may include forming sections of the encoded image stream 25 into data packets as appropriate for transmission over the transmission link 20 to the display apparatus 30.
Referring to Figures 3 and 4, two preferred embodiments of the display apparatus 30 will now be described.
13 Referring to Figure 3, the first preferred embodiment of the display apparatus 30 comprises a predictive decoding unit 32, a demultiplexer 34, and a display processing unit 36.
The predictive decoding unit 32 receives the encoded image stream 25 and performs predictive decoding to reproduce the original multiplexed image stream 15. The demultiplexer 34 demultiplexes the multiplexed image stream 15 to reproduce the original plurality of camera image streams 13. Each camera image stream 13 is ready for display on a display device 38 under control of the display processing unit 36, as will be familiar to the skilled person. Conveniently, one or more selected camera streams is displayed in a separate screen area of the display device 38. Alternatively, the decoded multiplexed image stream 15 may be displayed directly, in which case the user will see a short sequence of images from each camera.
Referring to Figure 4, a second preferred embodiment of the display apparatus 30 comprises a demultiplexing unit 341, a plurality of predictive decoding units 32, and a display processing unit 36. The demultiplexing unit 341 demultiplexes the encoded image stream 25 to produce a plurality of encoded camera image streams. Each predictive decoding unit 32' performs predictive decoding in order to reproduce one of the original camera image streams 13 ready for display on a display device 38.
Suitably, the display processing unit 36 includes a video encoder for performing digital to analogue conversion of the camera image stream 13 ready for display on an analogue display device 38 such as a monitor.
14 Advantageously, the first preferred embodiment of the display apparatus requires only one predictive decoding unit, but is relatively memory intensive during this processing operation and subsequent demultiplexing of the camera streams. By contrast, the second preferred embodiment of the display apparatus uses less memory, but requires slightly greater processing capacity in order to perform simultaneous predictive decoding of the plurality of camera image streams 13. The skilled person will select the desired display apparatus according to the needs of a particular application. In both cases, the display apparatus is relatively simple using readily available components and requires minimal adaptation in is order to successfully display the plurality of camera image streams. Hence, the preferred embodiments of the present invention are particularly suitable for use in adapting existing display equipment to receive images transmitted over a transmission link.
A method and apparatus have been described for the transmission of images from a plurality of surveillance cameras. The method and apparatus are particularly suited to the transmission of live images over a transmission link that has a limited bandwidth. Advantageously, the method and apparatus make efficient use of a predictive coding scheme in order to minimise bandwidth requirements, whilst maintaining a timely transmission of data.
The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
The invention is not restricted to the details of the foregoing embodiment(s). The invention extend to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
16
Claims (26)
1. A method for encoding images from a plurality of surveillance cameras, comprising the steps of:
(a) providing a camera image stream from each of a plurality of surveillance cameras; (b) multiplexing the camera image streams to provide a multiplexed image stream; and (c) predictive coding the multiplexed image stream to provide an encoded image stream.
2. A method as claimed in claim 1, wherein the multiplexing step (b) comprises time division multiplexing of the camera image streams.
3. A method as claimed in claim 1 or 2, wherein, in the step (a), each camera image stream comprises a sequence of independent still image frames; and in the step (b), the camera image streams are multiplexed based upon units each comprising a plurality of still image frames from each camera image stream.
4. A method as claimed in claim 3, wherein, in the step (c), the predictive coding forms a group of pictures (GOP) in the encoded image stream based on still image frames in the multiplexed image stream.
5. A method as claimed in claim 4, wherein each unit of still image frames in the multiplexed image stream forms a GOP in the encoded image stream.
17
6. A method as claimed in claim 5, wherein each GOP is an individual GOP.
7. A method as claimed in claim 5 or 6, wherein each unit of still image frames in the multiplexed image stream forms more than one GOP in the encoded image stream.
8. A method as claimed in any of claims 1 to 7, wherein each camera image stream comprises independent still image frames, and the method includes the step of (bi) compressing at least one of the independent still image frames using a non-predictive coding scheme.
9. A method for transmitting images from a plurality of surveillance cameras, the images being encoded according to the encoding method of any of claims 1 to 8, the transmission method comprising the step of (d) transmitting the encoded image stream over a transmission link.
10. A method as claimed in claim 9, wherein the transmission link includes a local area network of a computer system.
11. A method for decoding an encoded image stream provided according to the method of any of claims 1 to 10, the decoding method comprising the steps of:
(e) receiving the encoded image stream; (f) predictive decoding the encoded image stream to reproduce the multiplexed image stream; and 18 (g) demultiplexing the multiplexed image stream to reproduce at least one of the plurality of camera image streams.
12. A method for decoding an encoded image stream provided according to the method of any of claims 1 to 10, the decoding method comprising the steps of:
(e) receiving the encoded image stream; (fl) demultiplexing the encoded image stream to provide a plurality of demultiplexed image streams; and (gl) predictive decoding at least one of the demultiplexed image, streams to reproduce a respective one of the camera image streams for display on a display unit.
13. The method of claim 11 or 12, comprising the step of (h) displaying a selected one or more of the plurality of camera image streams on a display device.
14. A method for transmitting live images from a plurality of surveillance cameras for display on a display unit, the method comprising the steps of:
(a) providing a camera image stream from each of a plurality of surveillance cameras; (b) multiplexing the camera image streams to provide a multiplexed image stream; 19 (c) predictive coding the multiplexed image stream to provide an encoded image stream; (d) transmitting the encoded image stream over a 5 transmission link; (e) receiving the encoded image stream; (f) predictive decoding the encoded image stream to lo reproduce the multiplexed image stream; and (g) demultiplexing the multiplexed image stream to reproduce at least one of the plurality of camera image streams for display on a display unit.
15. A method for transmitting live images from a plurality of surveillance cameras for display on a display unit, the method comprising the steps of:
(a) providing a camera image stream from each of a plurality of surveillance cameras; (b) multiplexing the camera image streams to provide a multiplexed image stream; (c) predictive coding the multiplexed image stream to provide an encoded image stream; (d) transmitting the encoded image stream over a transmission link; (e) receiving the encoded image stream; (fl) demultiplexing the encoded image stream to provide a plurality of demultiplexed image streams; and (gl) predictive decoding at least one of the demultiplexed image streams to reproduce a respective one of the camera image streams for display on a display unit.
16. An apparatus for encoding images from a plurality of surveillance cameras, comprising:
a multiplexing unit for multiplexing a camera image stream from each surveillance camera to produce a multiplexed image stream; and is a predictive coding unit for predictive coding the multiplexed image stream to form an encoded image stream.
17. An apparatus as claimed in claim 16, comprising means for transmitting the encoded image stream over a 20 transmission link.
18. An apparatus for decoding an encoded image stream received from an encoding apparatus as claimed in claim 16 or 17, the decoding apparatus comprising:
a predictive decoding unit for predictive decoding the encoded image stream to reproduce the multiplexed image stream; and a display processing unit for controlling display of the multiplexed image stream on a display unit.
19. An apparatus as claimed in claim 18, wherein:
21 the display processing unit includes a demultiplexing unit for demultiplexing the multiplexed camera image stream to reproduce a selected one or more of the plurality of camera image streams; and the display processing unit controls the display unit to display the or each camera image stream as a separate continuous sequence of live images.
20. An apparatus for decoding an encoded image stream received from an encoding apparatus according to claim 16 or 17, the decoding apparatus comprising:
is a demultiplexing unit for demultiplexing the encoded image stream to produce a plurality of predictive coded camera image streams; and a plurality of predictive decoding units, each for predictive decoding one of the plurality of predictive coded camera image streams to reproduce a respective one of the camera image streams for display on a display unit.
21. A method for encoding images from a plurality of surveillance cameras, substantially as hereinbefore described with reference to the accompanying drawings.
22. A method for transmitting images from a plurality of surveillance cameras, substantially as hereinbefore described with reference to the accompanying drawings.
22
23. A method for decoding, substantially as hereinbefore described with reference to the accompanying drawings.
24. An encoding apparatus substantially as hereinbefore described with reference to the accompanying drawings.
25. A decoding apparatus substantially as hereinbefore described with reference to Figure 3 of the accompanying drawings.
26. A decoding apparatus substantially as hereinbefore described with reference to Figure 4 of the accompanying drawings.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0011374A GB2362284A (en) | 2000-05-12 | 2000-05-12 | Multiplexing and encoding images from muliple surveillance cameras |
| AU2001254964A AU2001254964A1 (en) | 2000-05-12 | 2001-05-10 | Method and apparatus for encoding and transmission of images from multiple surveillance cameras |
| PCT/GB2001/002063 WO2001086956A1 (en) | 2000-05-12 | 2001-05-10 | Method and apparatus for encoding and transmission of images from multiple surveillance cameras |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0011374A GB2362284A (en) | 2000-05-12 | 2000-05-12 | Multiplexing and encoding images from muliple surveillance cameras |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB0011374D0 GB0011374D0 (en) | 2000-06-28 |
| GB2362284A true GB2362284A (en) | 2001-11-14 |
Family
ID=9891395
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0011374A Withdrawn GB2362284A (en) | 2000-05-12 | 2000-05-12 | Multiplexing and encoding images from muliple surveillance cameras |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU2001254964A1 (en) |
| GB (1) | GB2362284A (en) |
| WO (1) | WO2001086956A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2378605A (en) * | 2001-07-04 | 2003-02-12 | Hewlett Packard Co | Route navigation using captured images |
| EP1333677A1 (en) * | 2002-01-31 | 2003-08-06 | BRITISH TELECOMMUNICATIONS public limited company | Video coding |
| DE102008049921A1 (en) * | 2008-09-29 | 2010-04-15 | Mobotix Ag | Method of video stream generation |
| US8953038B2 (en) | 2009-08-31 | 2015-02-10 | International Business Machines Corporation | Distributed video surveillance storage cost reduction using statistical multiplexing principle |
| WO2022256055A1 (en) * | 2021-06-02 | 2022-12-08 | Western Digital Technologies, Inc. | Data storage device and method for application-defined data retrieval in surveillance systems |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1581002A1 (en) * | 2004-03-25 | 2005-09-28 | Videte IT AG | Device and method for video signal processing |
| US7873078B2 (en) * | 2004-12-07 | 2011-01-18 | Displaylink (Uk) Limited | Screen multiplexing |
| CN109982008B (en) * | 2017-12-28 | 2021-07-20 | 浙江宇视科技有限公司 | Round-robin switching method and device and electronic equipment |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2253121A (en) * | 1991-01-24 | 1992-08-26 | Northern Telecom Ltd | Surveillance system sends compressed video down telephone line |
| US5253057A (en) * | 1990-12-20 | 1993-10-12 | Fujitsu Limited | Multiplexed transmission system of image data from two or more sources wherein thinning rates are adaptively allocated to respective sources |
| GB2318013A (en) * | 1997-11-20 | 1998-04-08 | Christopher Malcolm Hall | Television surveillance system wherein not all the mutiplexed video signals recorded are displayed |
| GB2337174A (en) * | 1998-05-08 | 1999-11-10 | Christopher Malcolm Hall | Multiplexing asynchronous analogue video signals in a security and surveillance system |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0564199A (en) * | 1991-08-29 | 1993-03-12 | Pioneer Electron Corp | Picture monitor |
| EP0717383B1 (en) * | 1994-12-14 | 2001-10-04 | THOMSON multimedia | Video surveillance method and device |
| US5724475A (en) * | 1995-05-18 | 1998-03-03 | Kirsten; Jeff P. | Compressed digital video reload and playback system |
| JPH11103473A (en) * | 1997-09-26 | 1999-04-13 | Toshiba Corp | Stereoscopic picture display device |
-
2000
- 2000-05-12 GB GB0011374A patent/GB2362284A/en not_active Withdrawn
-
2001
- 2001-05-10 AU AU2001254964A patent/AU2001254964A1/en not_active Abandoned
- 2001-05-10 WO PCT/GB2001/002063 patent/WO2001086956A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5253057A (en) * | 1990-12-20 | 1993-10-12 | Fujitsu Limited | Multiplexed transmission system of image data from two or more sources wherein thinning rates are adaptively allocated to respective sources |
| GB2253121A (en) * | 1991-01-24 | 1992-08-26 | Northern Telecom Ltd | Surveillance system sends compressed video down telephone line |
| GB2318013A (en) * | 1997-11-20 | 1998-04-08 | Christopher Malcolm Hall | Television surveillance system wherein not all the mutiplexed video signals recorded are displayed |
| GB2337174A (en) * | 1998-05-08 | 1999-11-10 | Christopher Malcolm Hall | Multiplexing asynchronous analogue video signals in a security and surveillance system |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2378605A (en) * | 2001-07-04 | 2003-02-12 | Hewlett Packard Co | Route navigation using captured images |
| GB2378605B (en) * | 2001-07-04 | 2003-12-31 | Hewlett Packard Co | Environmental imaging apparatus |
| EP1333677A1 (en) * | 2002-01-31 | 2003-08-06 | BRITISH TELECOMMUNICATIONS public limited company | Video coding |
| WO2003065730A1 (en) * | 2002-01-31 | 2003-08-07 | British Telecommunications Public Limited Company | Video coding |
| DE102008049921A1 (en) * | 2008-09-29 | 2010-04-15 | Mobotix Ag | Method of video stream generation |
| US9098910B2 (en) | 2008-09-29 | 2015-08-04 | Mobotix Ag | Method for generating video data stream |
| US8953038B2 (en) | 2009-08-31 | 2015-02-10 | International Business Machines Corporation | Distributed video surveillance storage cost reduction using statistical multiplexing principle |
| WO2022256055A1 (en) * | 2021-06-02 | 2022-12-08 | Western Digital Technologies, Inc. | Data storage device and method for application-defined data retrieval in surveillance systems |
| US11546612B2 (en) | 2021-06-02 | 2023-01-03 | Western Digital Technologies, Inc. | Data storage device and method for application-defined data retrieval in surveillance systems |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2001086956A1 (en) | 2001-11-15 |
| GB0011374D0 (en) | 2000-06-28 |
| AU2001254964A1 (en) | 2001-11-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1024664B1 (en) | Image-information storage regenerating device | |
| EP0661888B1 (en) | Multiplexing/demultiplexing method for superimposing sub- images on a main image | |
| US11044437B2 (en) | Method and system for combining multiple area-of-interest video codestreams into a combined video codestream | |
| US9100217B2 (en) | Apparatus, systems and methods for packet based transmission of multiple data signals | |
| EP0854652B1 (en) | Picture and sound decoding device, picture and sound encoding device, and information transmission system | |
| NO302210B1 (en) | Multichannel image compression system, and decoder device | |
| JPH06224861A (en) | Data separation processor | |
| KR100606785B1 (en) | Synchronization method of video and iamge data in system for providing remote multimedia service through network | |
| EP0618729B1 (en) | Video-signal transmitting and receiving apparatus and method thereof | |
| KR20010072769A (en) | Method of multichannel data compression | |
| GB2362284A (en) | Multiplexing and encoding images from muliple surveillance cameras | |
| JPH11122610A (en) | Image coding method, image decoding method and system for them | |
| JP2000032460A (en) | Method and system for generating selected image view | |
| JPH09130763A (en) | Still image transmitter | |
| US9479823B2 (en) | Transmitting device and receiving device | |
| JPH08191434A (en) | Moving picture/audio coding data multiplexing method and moving picture/audio coding data multiplexer | |
| JP2936627B2 (en) | Image decoding method with compensation for abandonment | |
| JP3750217B2 (en) | Video encoding transmission device | |
| JP3871217B2 (en) | Video receiver | |
| JP2005176068A (en) | Motion image distribution system and method therefor | |
| JP2001053702A (en) | Data transmitting method and data transmitting device | |
| JPH10243403A (en) | Dynamic image coder and dynamic image decoder | |
| EP0948208A1 (en) | Improvements in or relating to high definition encoding | |
| JP2001128145A (en) | Remote multiplexed picture monitor system | |
| JPH04132387A (en) | Pictorial communication equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |