KR100480520B1 - Method for transferring image signals and system using the method - Google Patents

Abstract

An image transmission method and a network camera system using the same are provided to transmit a digital image signal with high resolution and an analog image signal with low resolution to a DVR(Digital Video Recorder) system, to store the digital image signal to a memory and to display the analog image signal at real time by the DVR system. A high resolution image photographic member(210) photographs an object and generates a high resolution image signal. An A/D(Analog/Digital) converting member(220) converts the high resolution image signal into a digital image signal. An image signal compressing member(230) receives the digital image signal, compresses the digital image signal with the high definition and generates the first digital image signal. A down-scaling member(240) receives the digital image signal, performs a down-scaling operation of the digital image signal and generates the second digital image signal. A D/A converting member(250) converts the second digital image signal into the second analog image signal. An image signal converting member(260) converts the second analog image signal into the second LAN(Local Area Network) cable. A network interface member(270) is connected to a LAN cable and transmits the first digital image signal and the second LAN cable analog image signal to a predetermined DVR system through a LAN cable.

Description

Image transfer method and network camera system using the method {Method For Transferring Image Signals And System Using The Method}

The present invention relates to a network camera system and a video signal transmission method capable of simultaneously transmitting a high resolution digital video signal and a low resolution analog video signal through a LAN cable.

Digital video recorders (DVRs) are gaining popularity in the field of security surveillance based on digital video compression technology. The DVR is distinguished from the conventional analog storage device (VCR) and can digitize the input image and store it in a hard disk.

The biggest advantage of DVR is that it does not incur maintenance costs because it can periodically change and store the recording tapes, unlike the existing analog method. In addition, it is possible to search quickly in case of an accident and get clear picture quality. Also, it is possible to understand the situation actively by receiving video in real time through telephone line or internet network. ) In terms of use, functional excellence.

The DVR is mainly used to check the security status of the building, parking lot, bank, etc. by installing multiple cameras in the area where security is required. DVRs are generally similar to closed-circuit televisions (CCTVs) in terms of their use, but with a big difference in the way they operate. In addition, closed-circuit television (CCTV) records the video captured by the surveillance camera on video tape, and records and reads it through the VCR, whereas the DVR converts the video data input from the analog surveillance camera into a digital image, and records it on the hard disk. It is characterized by converting and storing high quality digital video signal.

In recent years, high resolution cameras capable of capturing high-definition images have been adopted in DVR systems, and their utility is increasing day by day. Images taken in accordance with the existing NTSC / PAL standard signal consisted of about 30-400,000 pixels, but images taken by high-resolution cameras that acquire images with high-resolution CCD / CMOS devices are basically 800,000 to 1.5 million pixels. It is made of high quality of Mega Pixel which reaches pixel.

Such a high resolution image has a number of advantages because the identification of the photographed subject is more obvious and easier, but in a transmission process of receiving and transmitting the high resolution image to a DVR, the network connects one or more high resolution cameras to the DVR. Overload may occur, and the load of a DVR that receives and processes an image from a high resolution camera through a network is greatly increased. The high resolution video signals compressed and transmitted from several high resolution network cameras have a very large data size, making it difficult to receive captured images in real time from the DVR due to the limitation of network transmission bandwidth. In order to display and decompress and analogize high-resolution video signals in real time, a high specification is required in terms of processing power and memory capacity of the DVR processor.

The present invention has been made to improve the prior art as described above, a high resolution digital image signal obtained from a high resolution image signal captured by a high resolution camera, and a low resolution analog image signal obtained through a process of downscaling the high resolution image signal. To the DVR system, and the DVR system stores the high resolution digital video signal in a predetermined memory, and provides a video transmission method and a network camera system capable of displaying the low resolution analog video signal in real time. do.

In addition, the present invention provides a video signal to the user in real time, and at the same time, if the user wants to provide the same scene as the video signal in a high resolution video signal, while preventing the overload in the DVR system and network And another object of the present invention is to provide a network camera system.

In addition, the present invention allows the simultaneous transmission of different types of video signals, such as high resolution digital video signals and low resolution analog video signals, over a LAN cable, thereby eliminating the need for a separate coaxial cable for transmitting low resolution analog video signals. Another object is to provide a transmission method and a network camera system.

In order to achieve the above object and solve the problems of the prior art, a network camera system according to the present invention, a high-resolution image pickup unit for photographing a subject to generate a high-resolution image signal, an analog for converting the high-resolution image signal into a digital image signal And a digital signal converter for receiving the digital video signal from the analog / digital converter and compressing the digital video signal in high resolution to generate a first digital video signal. A downscaling unit for receiving a digital video signal, downscaling the digital video signal to generate a second digital video signal, and a digital / converter for converting the second digital video signal to generate a second analog video signal. An analog converter to convert the second analog video signal Second LAN cable that can be transmitted by cable Video signal converting unit for converting into an analog video signal, and LAN cable is connected, the first digital video signal and the second LAN cable analog video signal to a predetermined DVR via the LAN cable It includes a network interface for transmitting to the system.

The network camera system according to the present invention receives the first digital video signal and the second LAN cable analog video signal, and converts the second LAN cable analog video signal to a second analog video signal that can be transmitted by a coaxial cable. The apparatus may further include a branching device for receiving the first digital video signal and the second LAN cable analog video signal input from the network interface unit through the LAN cable. A second interface unit for transmitting a first digital video signal to the DVR system, a second video signal converter for converting the second LAN cable analog video signal into a second analog video signal transmittable by a coaxial cable, and a coaxial cable The coaxial cable is connected to the converted second analog video signal. It includes a third interface portion for transmitting to the DVR system is connected.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 is a diagram illustrating a network connection of a network camera system of the present invention.

The network camera system 110 according to the present invention includes a camera installed at one or more places to photograph a subject of each place. The DVR system 130 receives and displays or stores an image signal input from the network camera system 110. The branch device 120 is connected to the network camera system 110 and internally and externally installed in the DVR system 130 to receive a high resolution digital video signal and a low resolution analog video signal from one or more network camera systems 110, respectively. The analog video signal is converted into a signal that can be transmitted by a coaxial cable and transmitted to the DVR system 130, respectively. The LAN cable 140 or the coaxial cable 150 is a medium for transmitting the video signal between the network camera system 110, the branch device 120, or the DVR system 130.

One or more cameras included in the network camera system 110 are respectively installed in an area to be photographed by a user, and the branch device 120 receives a high resolution image signal and a low resolution image signal photographing the installed area through the LAN cable 140. To send). A plurality of cameras of the network camera system 110 may be installed in one or more zones, or may move to a corresponding zone by taking a predetermined range and take an image. The camera widely used in the present specification is a camera that supports high resolution image capturing, and high resolution may generally support megapixel image capturing from about 800,000 pixels to about 1.5 million pixels.

The branch device 120 receives a high resolution digital video signal and a low resolution analog video signal from the network camera system 110, converts the low resolution analog video signal into a signal that can be transmitted by a coaxial cable, and transmits the same to the DVR system 130. . The internal configuration and operation of the branch device will be described later with reference to FIG. 4.

The DVR system 130 receives the high resolution digital video signal transmitted from the branch device 120 through the LAN card 131 connected to the LAN cable 140 and stores it in a predetermined memory means, and transmits it from the branch device 120. The low resolution analog video signal is received through the display module or the capture module 132 connected to the coaxial cable 150 and displayed in real time through a predetermined display means. A user of the DVR system 130 may view an image displayed in real time through the display means, and when the user wants to view an image captured by the scene, the user may search for and view a high resolution image signal stored in the memory means.

The LAN cable 140 is a medium for transmitting a high resolution video signal captured by the network camera system 110 to the LAN card unit 131 of the DVR system 130 through the branch device 120. The LAN cable 140 is mainly Ethernet. It is used as a connecting means to connect the. The LAN cable 140 referred to herein includes an unshielded twisted pair (UTP) cable, which is a commonly used copper telephone line.

The coaxial cable 150 is a medium for transmitting the low resolution analog signal transmitted through the branch device 120 to the DVR system 130.

Hereinafter, a network camera system according to an embodiment of the present invention will be described with reference to FIGS. 2 and 6.

The network camera system 200 according to FIG. 2 is classified into a high resolution image capturing unit 210, an analog / digital converting unit 220, an image signal compression unit 230, a down scaling unit 240, and a digital / analog converting unit ( 250, an image signal converter 260, and a network interface unit 270.

6 is a flowchart illustrating a network image transmission method performed by the network camera system 200.

In operation 610, the high resolution image capturing unit 210 photographs a subject to generate a high resolution image signal. The high-resolution imaging unit 210 is largely composed of a lens and a CCD / CMOS (not shown). When the light input to the lens is collected and transferred to the image sensor of the CCD / CMOS, the CCD / CMOS transmits the transmitted light to an electrical signal. To generate an analog video signal. The high resolution image capturing unit 210 may generate a high resolution image signal by photographing a subject at a mega pixel level of about 800,000 to 1.5 million pixels.

In step 620, the analog-to-digital converter 220 converts the analog image signal obtained through the high-resolution image capturing unit 210 into a digital image signal.

In operation 630, the image signal compressor 230 receives the digital image signal from the analog / digital converter 220 and compresses the digital image signal in high resolution to generate a first digital image signal. In this case, since the video quality may not be good when the DVR system 130 decompresses and reproduces the first video signal according to a compression method or a compression rate, the video signal compression unit 230 according to the present embodiment may be configured as described above. The first video signal is generated by compressing at high resolution so that data loss of the digital video signal is not large.

In operation 640, the down scaler 240 receives a digital video signal from the analog / digital converter 220, and down scales the digital video signal to a low resolution video signal to generate a second digital video signal. The digital image signal is an image signal captured by the high resolution image capturing unit 210 and has, for example, a mega pixel resolution. The down scaling unit 250 has such a high resolution digital video signal having a resolution of about 640 * 480 or 768 * 576 taken by a general NTSC / PAL camera, for example, about NTSC / PAL of about 30-400,000 pixels. Can be scaled down to a lower resolution of.

In operation 650, the digital / analog converter 250 converts the second digital video signal, which has been converted to a low resolution, through the down scaling unit 240 into an analog signal to generate a second analog video signal. The reason for converting the second digital video signal into an analog signal as described above is that the low resolution second digital video signal should be displayed in real time through the display means of the DVR system when transmitted to the DVR system. Since a general display means displays an analog video signal, the second digital video signal, which is a digital video signal, is converted into a second analog video signal through the digital / analog converter 250.

In operation 660, the video signal converter 260 converts the second analog video signal into a second LAN cable analog video signal that can be transmitted through a LAN cable. The second analog video signal is generally transmitted to the DVR system 130 through a coaxial cable, and the second analog video signal is transmitted to the DVR system 130 together through a LAN cable through which the first digital video signal is transmitted. In order to convert the second LAN cable into an analog video signal. For example, a LAN cable may be an unshielded twisted pair (UTP) cable, and the UTP cable may be connected to a connector such as an RJ-45 connector and may be connected to a PC or a hub.

The signal transmitted through the UTP cable is characterized by a differential signal consisting of two waveforms having a phase difference of 180 degrees from each other. Accordingly, in order to transmit the second analog signal to a LAN cable such as a UTP cable, the second analog cable may be converted into a second LAN cable analog video signal having characteristics of a differential signal and transmitted to the DVR system along with the first digital video signal through the LAN cable. .

In this embodiment, a case where the UTP cable is used as the LAN cable is taken as an example, but the video signal converter 260 converts the second analog video signal into an appropriate second LAN cable analog video signal according to the type of LAN cable used. I can convert it.

In operation 670, the network interface unit 270 transmits the first digital video signal and the second LAN cable analog video signal to the DVR system 130 through the LAN cable. The network interface unit 270 may be an RJ-11 configured as a 4PIN connector for a telephone, an RJ-45 configured as an 8PIN connector for a network used when connecting a LAN card or a hub, or a DB15 configured as a 15PIN connector for a serial console or monitor data cable. One can be used. Hereinafter, a configuration in which the network interface 270 is connected to a UTP cable using an RJ-45 connector will be described as an example.

3 is a view for explaining a signal transmitted to each pin of the RJ-45 connector of the network interface unit 270.

According to the present embodiment, the network interface unit 270 may use an RJ-45 connector for connection with a UTP cable, and the RJ-45 connector is composed of eight pins. In addition, by additionally transmitting DC power to the UTP cable according to the IEEE 802.3af regulations, it is possible to supply power to the network camera system 200 through the UTP cable without installing a separate power supply cable.

Referring to FIG. 3, a signal transmitted to each pin of the RJ-45 connector when only the first digital video signal is transmitted without supplying power through the UPT cable is the same as the reference numeral 310. In addition, the signal transmitted to each pin of the RJ-45 connector in the case of supplying power through the UPT cable and transmitting the first digital video signal is the same as the reference numeral 320.

Reference numeral 330 denotes a signal transmitted to each pin of the RJ-45 connector in the case of transmitting the first digital video signal and the second LAN cable analog video signal according to the present embodiment. That is, according to the present embodiment, power is supplied to the network camera system 200 through the UTP cable (see pins 1, 2, 3, and 6), but pins 4, 5, 7, and 8, which are not used in the prior art, are used. The second LAN cable may transmit an analog video signal. That is, as shown in FIG. 3, the second LAN cable analog video signal is transmitted as a differential signal such as Video A +, video A-, Video B +, or Video B-.

Therefore, according to the present embodiment, even when the coaxial cable for transmitting the second analog video signal is not installed, the second analog video signal is converted into the second LAN cable analog video signal and is together with the first digital video signal. It can be transmitted via LAN cable.

Hereinafter, a process of receiving an image signal transmitted from the network camera system 200 and storing or displaying it in the DVR system 130 will be described with reference to FIGS. 4, 5, and 7.

FIG. 4 is a block diagram showing a branching apparatus installed on the DVR system 130 side in this embodiment. The branch device 400 includes a first interface unit 410, a second interface unit 420, a second image signal converter 430, and a third interface unit 440.

In operation 710, the first interface unit 410 receives the first digital video signal and the second LAN cable analog video signal received from the network camera system 200 through the LAN cable. As described above, the second LAN cable analog video signal is a kind of analog video signal. The first interface unit 410 includes the same connector as the connector included in the network interface unit 270 of the network camera system 200. For example, when the RJ-45 connector as shown in FIG. 3 is used, the first interface unit 410 is a first input to pins 1, 2, 3 or 6 of the RJ-45 connector connected to the LAN cable. The digital video signal is transmitted to the second interface 420. In addition, the first interface unit 410 transmits the second LAN cable analog video signal input to pins 4, 5, 7, or 8 of the RJ-45 connector to the second production signal converter 430.

In operation 720, the second interface unit 420 transmits the transmitted first digital video signal to the DVR system 130 by bypass without any processing. The first digital video signal transmitted through the second interface unit 420 is stored in the memory means of the DVR system 130 in step 730. The memory means of the second interface unit 420 and the DVR system 130 may be connected by a LAN cable such as a UTP cable.

In operation 740, the second video signal converter 430 converts the second LAN cable analog video signal transmitted from the first interface unit 410 from the video signal converter 260 of the network camera system 200. The analog image signal (ie, the second analog image signal) before conversion is restored and transmitted to the third interface unit 440.

In operation 750, the third interface unit 440 transmits the second analog video signal transmitted from the second video signal converter 430 to the DVR system 130 connected through the coaxial cable. The second analog video signal transmitted through the third interface unit 440 is transmitted to the display module or the capture module of the DVR system 130 in step 760 to be real-time in a display device such as a TV, a PC monitor, or a PDP. Is displayed. The third interface unit 440 may include a coaxial cable connector for connection with the coaxial cable.

5 is a block diagram illustrating a connection relationship between the branch apparatuses 400 and 510 and the DVR systems 130 and 520 according to the present invention. For convenience of description, only the second interface unit 511 and the third interface unit 512 are shown in the branch device 510, and only the memory means 521 and the display means 522 are provided in the DVR system 520. The illustration of the other components is omitted.

The memory unit 521 of the DVR system 520 may classify and store the first digital video signal, which is a high resolution video signal transmitted from the second interface unit 511 of the branch device 510, by category. For example, the DVR system 520 may be stored for each shooting date corresponding to an identification number assigned to the high resolution network camera that captured the first digital video signal automatically or according to a user's designation.

The display means 522 displays the second analog video signal transmitted from the third interface unit 512 of the branch device 510 in real time. The second analog video signal is converted into a signal that can be transmitted by a coaxial cable through the second video signal converter of the branch device 510, so that the second analog video signal can be displayed immediately in real time on the display means 522 without any additional processing. .

The video signal transmission method using the network camera according to the present invention can be implemented in the form of program instructions that can be executed by various computer means can be recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. The medium may be a transmission medium such as an optical or metal wire, a waveguide, or the like including a carrier wave for transmitting a signal specifying a program command, a data structure, or the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

8 is an internal block diagram of a general-purpose computer device that may be employed to perform a video signal transmission method using a network camera according to the present invention.

Computer device 800 includes one or more processors 810 coupled with a main memory device including random access memory (RAM) 820 and read only memory (ROM) 830. The processor 810 is also called a central processing unit (CPU). As is well known in the art, the ROM 830 serves to transfer data and instructions to the CPU unidirectionally, and the RAM 820 typically transfers data and instructions bidirectionally. Used to. RAM 820 and ROM 830 may include any suitable form of computer readable media. Mass storage 840 is bidirectionally coupled to processor 810 to provide additional data storage capability, and may be any of the computer readable recording media described above. The mass storage device 840 is used to store programs, data, and the like, and is a secondary memory device such as a hard disk which is generally slower than the main memory device. Certain mass storage devices such as CD ROM 860 may be used. The processor 810 may include one or more input / output interfaces, such as video monitors, trackballs, mice, keyboards, microphones, touchscreen displays, card readers, magnetic or paper tape readers, voice or handwriting readers, joysticks, or other known computer input / output devices. 850 is connected. Finally, the processor 810 may be connected to a wired or wireless communication network through the network interface 870. Through this network connection, the procedure of the method described above can be performed. The apparatus and tools described above are well known to those skilled in the computer hardware and software arts.

The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention.

While specific embodiments of the present invention have been described so far, various modifications are possible without departing from the scope of the present invention.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below, but also by the equivalents of the claims.

According to the present invention, a high resolution digital video signal obtained from a high resolution video signal captured by a high resolution camera and a low resolution analog video signal obtained through downscaling the high resolution video signal are transmitted to a DVR system. The high resolution digital video signal is stored in a predetermined memory, and the low resolution analog video signal is provided with an image transmission method and a network camera system capable of displaying in real time.

In addition, according to the present invention, while providing a video signal to the user in real time, at the same time if the user wants to provide the same scene as the video signal in a high resolution video signal, while preventing the overload in the DVR system and network A transmission method and a network camera system are provided.

In addition, according to the present invention, it is possible to simultaneously transmit different types of video signals such as a high resolution digital video signal and a low resolution analog video signal through a LAN cable, and thus it is necessary to provide a separate coaxial cable for transmitting a low resolution analog video signal. An image transmission method and a network camera system are provided.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above-described embodiments, which can be variously modified and modified by those skilled in the art to which the present invention pertains. Modifications are possible. Accordingly, the spirit of the present invention should be understood only by the claims set forth below, and all equivalent or equivalent modifications thereof will belong to the scope of the present invention.

1 is a network diagram showing the overall configuration of a DVR system including a network camera system of the present invention.

Figure 2 is a block diagram showing the configuration of a network camera system according to an embodiment of the present invention.

Figure 3 is a view showing the cable pin configuration of the RJ-45 connector of the network interface unit according to the present invention.

4 is a block diagram showing the configuration of a branching apparatus according to the present invention;

5 is a diagram illustrating a connection configuration of a branch apparatus and a DVR system according to the present invention.

6 is a flowchart illustrating a procedure of a video signal transmission method using a network camera system of the present invention.

7 is a flowchart illustrating a procedure of a video signal receiving method in a branching apparatus and a DVR system of the present invention.

8 is an internal block diagram of a general-purpose computer device that can be employed to perform a video signal transmission method using a network camera according to the present invention.

<Explanation of symbols for the main parts of the drawings>

210: high resolution image capture unit 220: analog / digital converter

230: Image signal compression unit 240: Down scaling unit

250: digital / analog converter 260: video signal converter

270 network interface unit

Claims (13)

In the network camera system, A high resolution image photographing unit photographing a subject to generate a high resolution image signal; An analog / digital converting unit converting the high resolution image signal into a digital image signal; An image signal compression unit configured to receive the digital image signal from the analog / digital converter and to generate a first digital image signal by compressing the digital image signal at a high resolution; A down scaling unit configured to receive the digital image signal from the analog / digital converter, and to down scale the digital image signal to generate a second digital image signal; A digital / analog converter configured to convert the second digital video signal to generate a second analog video signal; An image signal conversion unit converting the second analog image signal into a second LAN cable analog image signal that can be transmitted by a LAN cable; And A network interface unit connected to a LAN cable and transmitting the first digital video signal and the second LAN cable analog video signal to a predetermined DVR system through the LAN cable. Network camera system comprising a. The method of claim 1, The video signal conversion apparatus receives the first digital video signal and the second LAN cable analog video signal, and converts the second LAN cable analog video signal into a second analog video signal that can be transmitted by a coaxial cable. Network camera system. The method of claim 1, The network camera system or the DVR system further comprises a branch device, The branching device, A first interface unit for receiving the first digital video signal and the second LAN cable analog video signal input from the network interface unit through the LAN cable; A second interface unit for transmitting the first digital video signal to the DVR system; A second video signal converter configured to convert the second LAN cable analog video signal into a second analog video signal that can be transmitted by a coaxial cable; And A third interface unit connected to a coaxial cable and transmitting the converted second analog video signal to the DVR system connected through the coaxial cable Network camera system comprising a. The method of claim 3, The second interface unit is a network camera system, characterized in that for transmitting the first digital video signal to the memory means of the DVR system. The method of claim 3, And the third interface unit transmits the second analog video signal to a display module or a capture module of the DVR system. The method of claim 1, The network interface unit network camera system, characterized in that it comprises an RJ-45 LAN cable pin. The method of claim 1, And said second LAN cable analog video signal is a differential signal. The method of claim 1, Low-resolution imaging unit for shooting a target subject to produce a low-resolution video signal Network camera system, characterized in that it further comprises. The method of claim 1, The high resolution image capturing unit photographs the subject to generate a mega pixel high resolution image signal of 800,000 pixels or more. The method of claim 1, And the downscaling unit converts the high resolution digital video signal into a second digital video signal having a resolution of NTSC / PAL of 400,000 pixels or less. In the video signal transmission method of the network camera, Photographing a subject to be directed to generate a high resolution image signal; Converting the high resolution video signal into a digital video signal; Compressing the digital video signal and converting the digital video signal into a first digital video signal; Generating a second digital video signal by down scaling the digital video signal; Generating a second analog video signal by converting the second digital video signal into an analog signal; Converting the second analog video signal into a second LAN cable analog video signal that can be transmitted by a LAN cable; And Transmitting the first digital video signal and the second LAN cable analog video signal to a predetermined DVR system through the LAN cable. Image signal transmission method of a network camera comprising a. The method of claim 11, Transmitting the first digital video signal and the second LAN cable analog video signal to a predetermined DVR system through the LAN cable, Receiving the first digital video signal and the second LAN cable analog video signal through the LAN cable; Transmitting the first digital video signal to the DVR system; Converting the second LAN cable analog video signal into a second analog video signal transmittable by a coaxial cable; And Transmitting the converted second analog video signal to the DVR system connected through the coaxial cable Image signal transmission method of a network camera comprising a. A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 11 and 12.