JP2005072879A - Remote image monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a remote image monitoring system capable of transmitting the video images of a plurality of monitoring cameras to a monitoring place by a common transmission line and obtaining the detailed images for the video images of a desired monitoring camera. <P>SOLUTION: The images of first-fourth analog monitoring cameras 211-214 provided inside a data input terminal 202 are respectively compressed in high compressibility encoders 221-224 and sent out to an IP network 203 and four images are divided and displayed on the monitor 242 of a monitoring terminal 205. When an operator selects one image, changeover to the transmission mode of the images of a low compressibility encoder 231 is performed for instance and the detailed images are displayed on the entire surface of the monitor 242. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a remote image monitoring system that monitors images obtained from a plurality of moving image shooting cameras by remote operation.

  For example, when the operation status of a ticket vending machine is monitored by video, not only a camera arranged at a position where the operator's face is projected but also a camera that projects the hand at the time of operation is required. Even when the hand is projected, it is necessary to arrange the cameras in two directions in order to allow the operator to cope with both right-handed and left-handed cases. In addition, in some cases, a camera that captures the movement of the person behind the operator may be required, or a camera that is arranged to look down from the ceiling side of the ticket vending machine may be required.

  In view of this, a remote image monitoring system has been proposed as a first proposal in which a plurality of video shooting cameras (hereinafter referred to as monitoring cameras) are used to remotely monitor a specific monitoring location. (For example, Patent Document 1).

FIG. 5 shows a remote image monitoring system according to the first proposal. In the remote image monitoring system 101, first to n-th monitoring cameras 103 _{1 to} 103 _n are arranged in a monitoring area 102. The first to n-th monitoring cameras 103 _{1 to} 103 _n are connected to encoders 105 _{1 to} 105 _n corresponding to the output sides thereof. These encoders 105 _{1 to} 105 _n encode image data in a predetermined format. For example, the video for each frame is encoded in an output format called motion JPEG as a frame feed video compressed by JPEG (Joint Photographic Experts Group), or MPEG-1 (Moving Picture Experts Group 1) or MPEG-2 as a moving image. The encoding is performed in an output format of (Moving Picture Experts Group 2) or MPEG-4 (Moving Picture Experts Group 4). The encoded image data is sent to an IP (Internet Protocol) network 106 and received by a monitoring terminal 107 on the IP network 106, so that the monitoring area 102 can be monitored.

In the first proposed remote image monitoring system 101, the encoders 105 _{1 to} 105 _n encode the outputs of the _first to n-th monitoring cameras 103 _{1 to} 103 _n using a predetermined encoding method. Therefore, there is only one type of encoding method, and the resolution and image size cannot be changed.

  Therefore, a second proposal has been made in which a plurality of images are displayed at once and a detailed image can be obtained for one of them (for example, Patent Document 2).

FIG. 6 shows a remote image monitoring system according to the second proposal. The remote image monitoring system 121 includes first to n-th monitoring units 122 _{1 to} 122 _n and a monitoring terminal 124 connected to the _first to n-th transmission lines 123 _{1 to} 123 _n . . Since the first to n-th monitoring units 122 _{1 to} 122 _n have the same configuration, the first monitoring unit 122 ₁ will be described here.

The first monitoring unit 122 ₁ includes a monitoring camera 125, a video data compression unit 126 that compresses video data obtained thereby, a compression control unit 127 that controls the compression content of the video data compression unit 126, and a first The bi-directional communication means 128 that performs bi-directional communication between the monitoring unit 122 ₁ and the monitoring terminal 124 is configured. The compression control unit 127 performs control to switch the compression content of the video data compression unit 126 from, for example, MPEG1 to MPEG2 or vice versa.

In this remote image monitoring system 121, it is assumed that the compression control means 127 of the first to n-th monitoring units 122 _{1 to} 122 _n instructs the video data compression means 126 to perform high compression on the video data. In this case, the monitoring terminal 124 can display each of the videos with relatively little information obtained from each of the _first to nth transmission lines 123 _{1 to} 123 _{n on} the multi-video screen at a time.

In this state, it is assumed that for example be observed first of the images obtained from the monitoring unit 122 ₁ in detail was requested. In this case, it is instructed from the monitor terminal 124 to the first monitoring unit 122 ₁ of the compression control unit 127. The compression control unit 127 controls the video data compression unit 126 in the _first monitoring unit 1221, and the detailed image can be obtained on the monitoring terminal 124 side.
JP 2002-354464 A (paragraph 0018, FIG. 1) JP 2000-165846 A (paragraph 0019, FIG. 1)

  In the second proposal, unlike the first proposal, a detailed image in which a predetermined image is detailed can be acquired if designated on the monitoring terminal 124 side. Therefore, in the example shown above, for example, a detailed image can be obtained if an image at the hand of the operator of the ticket vending machine is desired.

Incidentally, in the second proposed video data output from the monitoring unit 122 ₁ to 122 _n of the first to n is, monitoring terminal via a transmission path 123 ₁ ~123 _n of first through n respective dedicated Up to 124 is transmitted. Therefore, in this remote image monitoring system 121, if there is no problem in image processing on the monitoring terminal 124 side, it is possible to simultaneously acquire and process detailed images from all of the _first to nth monitoring units 122 _{1 to} 122 _n. It is. However, for this purpose, the total length of the _first to n-th transmission lines 123 _{1 to} 123 _n becomes very long, and the distance between the _first to n-th monitoring units 122 _{1 to} 122 _n and the monitoring terminal 124 is increased. If it is large, there is a problem that the cost required for laying these transmission paths becomes enormous.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a remote image monitoring system capable of transmitting images from a plurality of monitoring cameras through a common transmission path to a monitoring location and obtaining detailed images of the desired monitoring camera images. is there.

  According to the first aspect of the present invention, (b) output from at least a part of the plurality of surveillance cameras arranged at the position where the images of the respective photographing locations are photographed and (b) the plurality of surveillance cameras described above. High compression rate encoding means for encoding a video signal at a high compression rate; and (c) a low compression rate code for encoding a video signal output from at least a part of the plurality of monitoring cameras described above at a low compression rate. And (d) one transmission line in a time-division manner for the video signal encoded by the high compression ratio encoding means and the video signal encoded by the low compression ratio encoding means. (E) decoding means for decoding the video signal sent by the video signal sending means, (f) playback means for playing back the video signal decoded by the decoding means, (G) Transmission on the transmission line The remote image monitoring system includes video signal transmission instructing means for instructing transmission of a predetermined one of video signals encoded by the high compression ratio encoding means and the low compression ratio encoding means within an arbitrary range at an arbitrary time. Let

  That is, in the present invention, video signals output from a plurality of surveillance cameras are encoded by the high compression rate encoding unit and the low compression rate encoding unit, respectively, and the video signal transmission instruction unit instructs the video signal transmission. The data is sent to one transmission line in a time division manner and reproduced by the reproducing means. Therefore, a desired image is selected from a plurality of relatively low quality images compressed by the high compression rate encoding means, and the relatively high quality images encoded by the low compression rate encoding means are the same. It can be obtained via one transmission line.

  In the invention according to claim 2, (a) a plurality of surveillance cameras which are arranged at positions where images of respective photographing locations are photographed and which have high compression rate encoding means for encoding video signals at a high compression rate; (B) a low compression rate encoding means for encoding a video signal output from at least a part of the plurality of monitoring cameras described above at a low compression rate; and (c) a high compression rate encoding means in the monitoring camera. Video signal sending means for sending the video signal coded by the low-compression coding means and the video signal coded by the low compression rate coding means to one transmission line in a time-sharing manner; Decoding means for decoding the video signal sent by the video signal sending means, (e) Reproduction means for reproducing the video signal decoded by the decoding means, and (f) High compression rate within the transmission allowable range of the transmission path Encoding means and low compression rate Goka means the video signal transmission instructing means for instructing at any time the transmission of predetermined ones of the encoded video signal is provided to a remote image monitoring system by.

  That is, the present invention uses a plurality of surveillance cameras incorporating a high compression rate encoding means for encoding a video signal at a high compression rate as compared with the invention described in claim 1, so that the low compression rate encoding is performed separately. What is necessary is just to prepare a means.

  In the invention described in claim 3, (b) output from at least a part of the plurality of surveillance cameras arranged at the positions where the images of the respective photographing locations are photographed and (b) the plurality of surveillance cameras described above. High compression rate encoding means for encoding a video signal at a high compression rate; and (c) a low compression rate code for encoding a video signal output from at least a part of the plurality of monitoring cameras described above at a low compression rate. (D) a frame advance image encoding unit that encodes a video signal output from at least a part of the plurality of surveillance cameras as a frame advance image; and (e) a high compression rate encoding unit. One of the video signal encoded by the above, the video signal encoded by the low compression rate encoding means, and the frame-advanced image encoded by the frame-advanced image encoding means that is instructed by time division. On the transmission line (F) decoding means for decoding the video signal sent by the video signal sending means, (g) playback means for playing back the video signal decoded by the decoding means, H) Instructing the transmission of a predetermined one of video signals encoded by the high compression rate encoding means, the low compression rate encoding means, and the frame advance image encoding means within an allowable transmission range of the transmission path at an arbitrary time point And a video signal transmission instruction means for providing the remote image monitoring system.

  That is, the present invention includes frame advance image encoding means for encoding a video signal output from at least a part of a plurality of surveillance cameras as a frame advance image as compared with the invention described in claim 1, Three types of video signals output from the surveillance camera are prepared, and these are selected within a range allowable by one transmission path by the video signal transmission instruction means and transmitted to the reproduction side.

  In the invention described in claim 4, (a) a plurality of surveillance cameras which are arranged at positions where images of respective photographing locations are photographed and which incorporate high compression rate encoding means for encoding video signals at a high compression rate; (B) a low compression rate encoding means for encoding a video signal output from at least a part of the plurality of monitoring cameras described above at a low compression rate; and (c) at least one of the plurality of monitoring cameras described above. A frame-advanced image encoding unit that encodes a video signal output from the unit as a frame-advanced image, and (d) a video signal encoded by a high-compression rate encoding unit in the surveillance camera A video signal sending means for sending a video signal encoded by the means and a frame advance image encoded by the frame advance image encoding means to one transmission path in a time-division manner; E) This video Decoding means for decoding the video signal sent by the signal sending means, (f) reproduction means for reproducing the video signal decoded by the decoding means, and (g) a high compression rate code within the transmission allowable range of the transmission path. And a video signal transmission instruction means for instructing transmission of a predetermined one of the video signals encoded by the encoding means, the low compression ratio encoding means and the frame advance image encoding means at any time point in the remote image monitoring system Provide.

  That is, the present invention comprises frame advance image encoding means for encoding a video signal output from at least a part of a plurality of surveillance cameras as a frame advance image as compared with the invention according to claim 2, Three types of video signals output from the surveillance camera are prepared, and these are selected within a range allowable by one transmission path by the video signal transmission instruction means and transmitted to the reproduction side.

  According to a fifth aspect of the present invention, in the remote image monitoring system according to any one of the first to fourth aspects, an IP address is assigned to each of the monitoring camera and the encoding means, and the transmission path is configured by a LAN cable. The video signal transmitting means transmits the video signal by IP packet to the monitoring terminal on the monitoring side via the LAN cable and the IP network.

  That is, in the present invention, the IP address is specified and each video signal is transmitted in the form of an IP packet. Since an IP network is used, this remote image monitoring system can be easily configured regardless of location.

  According to a sixth aspect of the present invention, in the remote image monitoring system according to any one of the first to fourth aspects, the reproducing means reproduces the images of the plurality of surveillance cameras encoded by the high compression rate encoding means. When the display screen is divided and displayed simultaneously for a plurality of screens, when the video of a specific surveillance camera encoded by the low compression rate encoding means is reproduced, one screen is displayed using the entire display screen, The video signal transmission instructing means is a touch panel arranged in front of the display screen.

  That is, in the present invention, when a plurality of screens are divided and displayed, if a desired screen is indicated on the touch panel, a detailed image of the screen can be acquired, and a remote image monitoring system with excellent operability can be obtained.

  As described above, according to the present invention, video signals output from a plurality of surveillance cameras are encoded by the high compression rate encoding unit and the low compression rate encoding unit, respectively, or the video signal is encoded as a frame advance image. Thus, what is instructed by the video signal transmission instructing means is time-divisionally transmitted to one transmission path by the video signal transmitting means and reproduced by the reproducing means. Accordingly, it is possible to observe and record a detailed image selected from several relatively low quality images while limiting the amount of data transmitted per unit time.

  Moreover, if the image capturing side and the monitoring side are connected using an IP network, the image capturing side and the monitoring side can be selected relatively freely, and an existing network can be used. System construction time and costs can be saved.

<First Embodiment>

  FIG. 1 shows an overview of a remote image monitoring system according to the first embodiment of the present invention. The remote image monitoring system 201 includes a data input terminal 202 arranged at a monitoring location (not shown), an IP (Internet Protocol) network 203, a first transmission path 204 connecting the data input terminal 202 and the IP network 203, The monitoring terminal 205 on the monitoring side and the second transmission path 206 connecting the IP network 203 and the monitoring terminal 205 are configured. In the data input terminal 202, four monitoring cameras, ie, first to fourth analog monitoring cameras 211 to 214 that output analog video signals, respectively, are arranged. For example, when the monitoring place is a ticketing machine (not shown) as described above, the first analog monitoring camera 211 is arranged at a position that reflects the operator's face, and the second analog monitoring camera 212 is located above the ticketing machine. It is arranged in a position overlooking from. The third analog surveillance camera 213 is disposed at a position where the operator panel of the ticketing machine is projected from the right hand side of the operator, and the fourth analog surveillance camera 214 is disposed at a position where the operator panel of the ticket issuing machine is projected from the left hand side of the operator. Is arranged. The first to fourth analog surveillance cameras 211 to 214 are existing cameras, and the components that have been used conventionally can be effectively used by appropriately using these cameras.

  The video signal output from the first analog surveillance camera 211 is input to the first high compression rate encoder 221, and the first high compression rate encoder 221 compresses the image by MPEG4. A first low compression ratio encoder 231 is disposed on the output side of the first high compression ratio encoder 221. The low compression rate encoder 231 according to the present embodiment compresses an image using MPEG2. The video signal output from the second analog surveillance camera 212 is input to the second high compression ratio encoder 222, and a second low compression ratio encoder 232 is disposed on the output side. The same applies hereinafter, and a third high-compression-rate encoder 223 is disposed on the output side of the third analog surveillance camera 213, and a third low-compression-rate encoder 233 is disposed on the output side thereof. Further, a fourth high compression ratio encoder 224 is disposed on the output side of the fourth analog surveillance camera 214, and a fourth low compression ratio encoder 234 is disposed on the output side thereof.

  In the first embodiment, the first transmission path 204 and the second transmission path 206 are both transmission paths configured by a connection method using Ethernet (registered trademark), and IP packets are transmitted via the IP network 203. Is supposed to be transmitted. The IP network 203 means a network using IP technology. These are constituted by, for example, Ethernet (registered trademark) or an intranet. The first transmission line 204 that connects the first to fourth high compression ratio encoders 221 to 224 and the first to fourth low compression ratio encoders 231 to 234 and the IP network 203 via the transmission circuit 236 is a LAN ( It may be a Local Area Network (CA) cable or a meta cable using DSL (Digital Subscriber Line) technology such as ADSL (Asymmetric Digital Subscriber Line).

  In the data input terminal 202, the output of a predetermined encoder from the first to fourth high compression ratio encoders 221 to 224 and the first to fourth low compression ratio encoders 231 to 234 is sent to the first transmission line 204. A transmission circuit 236 for sending to the side is provided. The transmission circuit 236 initially transmits the video signals output from the first to fourth high compression ratio encoders 221 to 224 to the first transmission line 204 in the time division manner in the form of IP packets. As will be described later, when there is an instruction from the monitoring terminal 205, video signals such as those instructed in the first to fourth low compression rate encoders 231 to 234 are similarly sent in the form of IP packets. The data is sent to the first transmission path 204.

  First to fourth analog monitoring cameras 211 to 214 in the data input terminal 202, first to fourth high compression ratio encoders 221 to 224, first to fourth low compression ratio encoders 231 to 234, and a monitoring terminal 205 Are assigned IP addresses, and can be distinguished from each other in the remote image monitoring system 201. The data input terminal 202 grasps the IP address of each component such as the first to fourth analog monitoring cameras 211 to 214 constituting the remote image monitoring system 201. The monitoring terminal 205 also sends the bit rates of the first to fourth high compression ratio encoders 221 to 224 and the first to fourth low compression ratio encoders 231 to 234 and the number of frames sent per second from them. The predetermined information such as is set in an internal nonvolatile memory (not shown).

  Such a monitoring terminal 205 is constituted by a personal computer, for example. In this monitoring terminal 205, a decoder 241 that extracts and decodes the IP packet storing the compressed image signal sent via the second transmission path 206 for each IP address that has been sent, and this decoder 241 A monitor 242 for displaying the image decoded at is arranged. The decoder 241 distinguishes and decodes the image signal compressed by MPEG4 and the image signal compressed by MPEG2.

  On the monitor 242 of the monitoring terminal 205, four screen images obtained by initially compressing the image signals obtained from the first to fourth analog monitoring cameras 211 to 214 with MPEG4 are displayed by screen division. ing. A touch panel 243 is disposed on the front surface of the monitor 242. If a desired screen is selected on the touch panel 243 in a state where images of four screens by the first to fourth analog surveillance cameras 211 to 214 are displayed on the monitor 242, high quality compressed by MPEG2 corresponding to the screen. Are displayed on one screen.

  When the touch panel 243 is pressed while a high-quality image compressed by MPEG2 for one screen of any of the first to fourth analog surveillance cameras 211 to 214 is displayed on the monitor 242, the first again Images of four screens obtained by compressing the image signals obtained from the fourth analog surveillance cameras 211 to 214 with MPEG4 are displayed by screen division. As described above, by simply operating the touch panel 243, it is possible to easily switch between four screen images and one screen representing one detailed image.

  FIG. 2 is a view for explaining control of image acquisition and switching in the remote image monitoring system. However, in order to eliminate the complexity of illustration and description, in this example, only the case where a video signal is output from the first analog monitoring camera 211 will be illustrated and described. An NTSC (National Television System Committee) video signal 251 output from the first analog surveillance camera 211 is input to the first high-compression-ratio encoder 221, where it is converted into an IP that has been compressed by MPEG4. A first image signal 252 is obtained. MPEG4 is a compression format premised on use in a communication environment of 64 kbps (bits / second) or less. In this compression format, an image to be compressed is decomposed into individual objects such as people, character strings, and backgrounds, and each is compressed, so that even in a low-speed communication environment, a certain amount of High image quality can be achieved.

  On the other hand, the video signal 251 output from the first analog surveillance camera 211 passes through the first high compression rate encoder 221 as it is and is also input to the first low compression rate encoder 231 where the video signal is compressed by MPEG2. A second image signal 253 that has been converted to IP is obtained. MPEG2 is a scheme aiming for higher image quality than MPEG4, and is used for digital satellite broadcasting, DVD (Digital Versatile Disc) video, and the like. Thus, based on the video signal 251 output from the first analog surveillance camera 211, the first image signal 252 having a relatively low image quality compressed by MPEG4 and the image having a relatively high image quality compressed by MPEG2. The second image signal 253 is obtained at the same time.

  As described above, in the initial monitoring mode, the monitoring terminal 205 performs connection connection with the first high compression ratio encoder 221 (step S301), whereby the first image signal from the first analog monitoring camera 211 is obtained. 252 is sent to the monitoring terminal 205 (step S302), input to the decoder 241 shown in FIG. 1, and displayed on the monitor 242. At this time, although not shown in FIG. 2, the same first MPEG4 image signal 252 of the second to fourth analog monitoring cameras 212 to 214 is sent to the monitoring terminal 205. Accordingly, four screens based on MPEG4 are displayed at respective positions obtained by dividing the monitor 242 into four (step S303 in FIG. 2). Of course, the image signals of these four screens can be recorded and reproduced by using a moving image recording / reproducing apparatus (not shown).

  In this state, it is assumed that the operator of the monitoring terminal 205 presses the touch panel 243 at a position corresponding to the screen corresponding to the first analog monitoring camera 211, for example. Then, the connection between the monitoring terminal 205 and the first high compression rate encoder 221 is disconnected (step S304). Although not shown, the connection between the monitoring terminal 205 and the second to fourth high compression rate encoders is also disconnected in the same manner. Instead, the connection between the monitoring terminal 205 and the first low compression ratio encoder 231 is connected (step S305). As a result, transmission of a relatively high-quality image captured by the first analog monitoring camera 211 and compressed by MPEG2 is started to the monitoring terminal 205 (step S306), and is displayed as one screen on the entire surface of the monitor 242. (Step S307 in FIG. 2). Of course, this image signal can be recorded and reproduced by using the moving image recording / reproducing apparatus described above. In order to end the display of the one-screen image, the connection between the monitoring terminal 205 and the first low-compression encoder 231 may be disconnected (step S308).

  Of course, as described above, the operator of the monitoring terminal 205 selects a desired other screen on the touch panel 243 while returning to the 4-screen display, and this screen is displayed as a relatively high-quality image from MPEG4 to MPEG2. It becomes possible to switch to and display. That is, it is possible to perform an operation of sequentially switching MPEG2 relatively high-quality images screen by screen.

  In this embodiment, switching between a compressed image based on MPEG4 and a compressed image based on MPEG2 has been described. However, a moving image is compressed in another or a different compression format, or another output format such as motion JPEG. Can be switched between. In the above-described embodiment, in order to display a relatively high-quality image on one screen, it is necessary to return to a comparatively low-quality image once. However, this is not always necessary. For example, after the monitoring terminal 205 establishes a connection with the first low-compression-rate encoder 231, the connection is disconnected after a predetermined time has elapsed, and then the connection with the second low-compression-rate encoder 232 is established. After the predetermined time elapses, the connection is disconnected, and then the third low compression ratio encoder 233 is connected to the connection. After the predetermined time elapses, the connection is disconnected, and then the fourth low compression ratio encoder 234 is connected to the connection. By repeating the process of making a connection and disconnecting the connection after the lapse of a predetermined time, automatic circulation with an MPEG2 image becomes possible.

  In this embodiment, when switching the image on the monitor 242, the operation of always disconnecting the connection between the monitoring terminal 205 and the corresponding encoder is performed, but this is not always necessary. For example, if there is no fear that the transmission capacity of the IP packet between the first transmission path 204 and the second transmission path 206 shown in FIG. The connections may be selected and selected one by one from the first to fourth low-compression-rate encoders 231 to 234 while the connection between 221 to 224 is connected. For example, the bit rate of the image signal compressed with MPEG4 is 64 kbps to 3 Mbps, and the bit rate of the image signal compressed with MPEG2 is 3 Mbps to 6 Mbps. Is possible.

  Further, in this embodiment, an example in which the NTSC system is used as a monitoring camera has been described. However, it is naturally possible to use a monitoring camera of a PAL (Phase Alternation by Line) system or a SECAM (SEquential Couleur A Memoire) system. It is. Of course, the number of monitoring cameras used for monitoring of the monitoring terminal is not limited to this embodiment. Furthermore, it is natural that the surveillance camera may be a digital surveillance camera as well as the so-called analog surveillance camera shown in the present embodiment.

<Second Embodiment>

  FIG. 3 shows an outline of a remote image monitoring system according to the second embodiment of the present invention. In FIG. 3, the same parts as those in FIG. The remote image monitoring system 401 includes a data input terminal 402 arranged at a monitoring location (not shown), an IP network 203, a first transmission path 204 connecting the data input terminal 402 and the IP network 203, and a monitoring side. And a second transmission line 206 connecting the IP network 203 and the monitoring terminal 205. In the data input terminal 402, first to fourth IP surveillance cameras 411 to 414 are arranged. The first to fourth IP surveillance cameras 411 to 414 are cameras incorporating MPEG4 moving image compression encoders, respectively, and output the video as IP.

  The video signal output from the first IP surveillance camera 411 is input to the first low compression rate encoder 231. The low compression rate encoder 231 according to the present embodiment compresses images using MPEG2. A second low compression ratio encoder 232 is disposed on the output side of the second IP surveillance camera 412. The same applies hereinafter, and a third low compression ratio encoder 233 is disposed on the output side of the third IP surveillance camera 413. A fourth low compression rate encoder 234 is disposed on the output side of the fourth IP surveillance camera 414.

  In the data input terminal 402, the output of a predetermined encoder from the high compression ratio encoder (not shown) and the first to fourth low compression ratio encoders 231 to 234 in the first to fourth IP surveillance cameras 411 to 414. Is sent to the first transmission path 204 side. Initially, the transmission circuit 236 transmits video signals compressed by MPEG4 output from the first to fourth IP surveillance cameras 411 to 414 to the first transmission line 204 in the form of IP packets in a time division manner. As will be described later, when there is an instruction from the monitoring terminal 205, video signals such as those instructed in the first to fourth low compression rate encoders 231 to 234 are similarly sent in the form of IP packets. The data is sent to the first transmission path 204.

  IP addresses are assigned to the first to fourth IP surveillance cameras 411 to 414, the first to fourth low compression rate encoders 231 to 234 and the monitoring terminal 205 in the data input terminal 402, and the remote image monitoring system Each can be distinguished within 401. The data input terminal 402 grasps the IP address of each component such as the first to fourth IP monitoring cameras 411 to 414 constituting the remote image monitoring system 401. In addition, the monitoring terminal 205 stores predetermined information such as the bit rate of the first to fourth low compression ratio encoders 231 to 234 and the number of frames per second transmitted from these in an internal nonvolatile memory (not shown). It is set.

  Such a monitoring terminal 205 is constituted by a personal computer, for example. In this monitoring terminal 205, a decoder 241 that extracts and decodes the IP packet storing the compressed image signal sent via the second transmission path 206 for each IP address that has been sent, and this decoder 241 A monitor 242 for displaying the image decoded at is arranged. The decoder 241 distinguishes and decodes the image signal compressed by MPEG4 and the image signal compressed by MPEG2.

  On the monitor 242 of the monitoring terminal 205, four screen images compressed by MPEG4 initially obtained from the first to fourth IP surveillance cameras 411 to 414 are displayed by screen division. A touch panel 243 is disposed on the front surface of the monitor 242. If a desired screen is selected on the touch panel 243 in a state where images for four screens by the first to fourth IP surveillance cameras 411 to 414 are displayed on the monitor 242, high quality compressed with MPEG2 corresponding to the screen. Are displayed on one screen.

  FIG. 4 is a diagram for explaining video acquisition and switching control in this remote image monitoring system, and corresponds to FIG. 2 of the first embodiment. In this figure, only the case where a video signal is output from the first IP surveillance camera 411 will be described in order to eliminate the complexity of illustration and description. The first IP surveillance camera 411 incorporates an MPEG4 moving image compression encoder as described above. This encoder encodes an image signal in the MPEG4 format and outputs a first image signal 452. MPEG4 is a compression format premised on use in a communication environment of 64 kbps (bits / second) or less. In this compression format, an image to be compressed is decomposed into individual objects such as people, character strings, and backgrounds, and each is compressed, so that even in a low-speed communication environment, a certain amount of High image quality can be achieved.

  Separately from this, the first IP surveillance camera 411 outputs an NTSC (National Television System Committee) video signal 251. This video signal 251 is input to the low compression ratio encoder 231, where a second image signal 253 that has been converted to an IP and subjected to video compression by MPEG2 is obtained. MPEG2 is a scheme aiming for higher image quality than MPEG4, and is used for digital satellite broadcasting, DVD (Digital Versatile Disc) video, and the like.

  In the initial monitoring mode of the second embodiment, the monitoring terminal 205 establishes connection with the first IP monitoring camera 411 (step S501), whereby the MPEG4 format first image signal 452 is transferred to the monitoring terminal 205. (Step S 502), input to the decoder 241 shown in FIG. 3 and displayed on the monitor 242. At this time, although not shown in FIG. 4, the same first MPEG4 image signal 252 of the second to fourth IP surveillance cameras 412 to 414 is sent to the surveillance terminal 205. Accordingly, four screens based on MPEG4 are displayed at respective positions obtained by dividing the monitor 242 into four parts (step S503 in FIG. 2). Of course, the image signals of these four screens can be recorded and reproduced by using a moving image recording / reproducing apparatus (not shown).

  In this state, it is assumed that the operator of the monitoring terminal 205 presses the touch panel 243 at a position corresponding to the screen corresponding to the first IP monitoring camera 411, for example. Then, the connection between the monitoring terminal 205 and the first IP monitoring camera 411 is disconnected (step S504). Although not shown, the connection between the monitoring terminal 205 and the second to fourth IP monitoring cameras 412 to 414 is also disconnected in the same manner. Instead, the connection between the monitoring terminal 205 and the first low compression ratio encoder 231 is connected (step S505). As a result, transmission of a relatively high-quality image captured by the first IP surveillance camera 411 and compressed by MPEG2 is started to the surveillance terminal 205 (step S506), and is displayed as one screen on the entire surface of the monitor 242. (Step S507 in FIG. 2). Of course, this image signal can be recorded and reproduced by using the moving image recording / reproducing apparatus described above. In order to terminate the display of this one-screen image, the connection between the monitoring terminal 205 and the first low-compression-rate encoder 231 may be disconnected (step S508).

  Of course, as described above, the operator of the monitoring terminal 205 selects a desired other screen on the touch panel 243 while returning to the 4-screen display, and this screen is displayed as a relatively high-quality image from MPEG4 to MPEG2. It becomes possible to switch to and display. That is, it is possible to perform an operation of sequentially switching MPEG2 relatively high-quality images screen by screen.

  In the first and second embodiments described above, the touch panel is used for designating the screen on the monitor. However, other well-known input means such as a numeric keypad and voice input can be used. Further, the number of surveillance cameras arranged as data input terminals does not have to be the one shown in the embodiment, and the number is not particularly limited as long as it is a plurality. In the embodiment described above, the compressed image signal is transmitted using the IP network. However, the image signal can be transmitted in the same manner even if another transmission path is used.

  In the first and second embodiments, only the case where an image is displayed on the monitor has been described. However, not only video but also audio is captured on the data input terminal side, and audio is reproduced together with video on the monitoring terminal side. Of course, it may be.

1 is a system configuration diagram showing an overview of a remote image monitoring system according to a first embodiment of the present invention. It is explanatory drawing which showed control of acquisition and switching of an image | video with the remote image monitoring system of 1st Embodiment. It is a system block diagram showing the outline | summary of the remote image monitoring system in the 2nd Embodiment of this invention. It is explanatory drawing which showed control of acquisition and switching of an image | video with the remote image monitoring system of 2nd Embodiment. It is a system block diagram which showed the remote image monitoring system by the conventional 1st proposal. It is the system block diagram which showed the remote image monitoring system by the conventional 2nd proposal.

Explanation of symbols

201, 401 Remote image monitoring system 202, 402 Data input terminal 203 IP network 204 First transmission path 205 Monitoring terminal 206 Second transmission path 211-214 Analog monitoring camera 221-224 High compression ratio encoder 231-234 Low compression ratio Encoder 236 Transmission circuit 241 Decoder 242 Monitor 243 Touch panel 411-414 IP surveillance camera

Claims (6)

A plurality of surveillance cameras arranged at positions to capture images of each shooting location;
A high compression rate encoding means for encoding a video signal output from at least a part of the plurality of surveillance cameras at a high compression rate;
Low compression rate encoding means for encoding a video signal output from at least a part of the plurality of surveillance cameras at a low compression rate;
Video signal transmission for transmitting the video signal encoded by the high compression rate encoding means and the video signal encoded by the low compression rate encoding means to a single transmission line in a time division manner Means,
Decoding means for decoding the video signal sent by the video signal sending means;
Reproducing means for reproducing the video signal decoded by the decoding means;
Video signal transmission instruction means for instructing transmission of a predetermined one of video signals encoded by the high compression ratio encoding means and the low compression ratio encoding means within an allowable transmission range of the transmission path at an arbitrary time point; A remote image monitoring system comprising: A plurality of surveillance cameras which are arranged at positions where images of respective photographing locations are photographed, and which incorporate high compression rate encoding means for encoding video signals at a high compression rate;
Low compression rate encoding means for encoding a video signal output from at least a part of the plurality of surveillance cameras at a low compression rate;
Of the video signal encoded by the high compression rate encoding means and the video signal encoded by the low compression rate encoding means in the surveillance camera, the one that has been instructed is time-divided into one transmission line. Video signal sending means for sending;
Decoding means for decoding the video signal sent by the video signal sending means;
Reproducing means for reproducing the video signal decoded by the decoding means;
Video signal transmission instruction means for instructing transmission of a predetermined one of video signals encoded by the high compression ratio encoding means and the low compression ratio encoding means within an allowable transmission range of the transmission path at an arbitrary time point; A remote image monitoring system comprising: A plurality of surveillance cameras arranged at positions to capture images of each shooting location;
A high compression rate encoding means for encoding a video signal output from at least a part of the plurality of surveillance cameras at a high compression rate;
Low compression rate encoding means for encoding a video signal output from at least a part of the plurality of surveillance cameras at a low compression rate;
A frame advance image encoding means for encoding a video signal output from at least a part of the plurality of surveillance cameras as a frame advance image;
There was an instruction among the video signal encoded by the high compression ratio encoding means, the video signal encoded by the low compression ratio encoding means, and the frame advance image encoded by the frame advance image encoding means. Video signal sending means for sending a thing to one transmission line in a time-sharing manner;
Decoding means for decoding the video signal sent by the video signal sending means;
Reproducing means for reproducing the video signal decoded by the decoding means;
Transmission of a predetermined one of the video signals encoded by the high compression rate encoding means, the low compression rate encoding means, and the frame advance image encoding means within an allowable transmission range of the transmission path at an arbitrary time point A remote image monitoring system, comprising: a video signal transmission instruction means for instructing at A plurality of surveillance cameras which are arranged at positions where images of respective photographing locations are photographed, and which incorporate high compression rate encoding means for encoding video signals at a high compression rate;
Low compression rate encoding means for encoding a video signal output from at least a part of the plurality of surveillance cameras at a low compression rate;
A frame advance image encoding means for encoding a video signal output from at least a part of the plurality of surveillance cameras as a frame advance image;
The video signal encoded by the high compression ratio encoding means in the surveillance camera, the video signal encoded by the low compression ratio encoding means, and the frame advance image encoded by the frame advance image encoding means Video signal sending means for sending one of the instructions to one transmission line in a time-sharing manner,
Decoding means for decoding the video signal sent by the video signal sending means;
Reproducing means for reproducing the video signal decoded by the decoding means;
Transmission of a predetermined one of the video signals encoded by the high compression rate encoding means, the low compression rate encoding means, and the frame advance image encoding means within an allowable transmission range of the transmission path at an arbitrary time point A remote image monitoring system, comprising: a video signal transmission instruction means for instructing at   An IP address is assigned to each of the monitoring camera and the encoding means, the transmission path is constituted by a LAN cable, and the video signal sending means is sent to the monitoring terminal on the monitoring side via the LAN cable and the IP network. The remote image monitoring system according to claim 1, wherein the video signal is transmitted by an IP packet.   The reproduction means divides a display screen and simultaneously displays a plurality of screens when reproducing the images of the plurality of surveillance cameras encoded by the high compression ratio encoding means, and encodes by the low compression ratio encoding means When the video of the specified surveillance camera is reproduced, one screen is displayed using the entire display screen, and the video signal transmission instructing means is a touch panel disposed on the front of the display screen. The remote image monitoring system according to any one of claims 1 to 4.

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