KR19990053519A - Remote Quality Control at Video Terminal - Google Patents

Abstract

The present invention relates to an apparatus for controlling the image quality of a remote terminal in a video terminal.

This present vision is a video camera 301; An analog-to-digital converter 302 for converting the output of the video camera to digital; A captured image storage unit 303 for storing image data of a predetermined size input through an analog-digital converter; An image compression unit 304 for compressing and encoding an image of the captured image storage unit; An image quality remote control unit 310 outputting image quality control information in a predetermined format according to a user's control; A multiplexing unit 305 for multiplexing the output of the image compression unit and the image quality remote control unit into a predetermined frame, and a demultiplexing unit 331 for demultiplexing the received bit stream to separate the video stream and the image quality control stream; An image restorer 332 for decoding the video stream output by the demultiplexer; A digital-analog converter 334 for converting the reconstructed image into an analog signal; A quality control information decoder 320 for decoding a quality control stream output by the demultiplexer and outputting a control signal; And display means 335 for adjusting image quality related parameter values according to the control signal of the image quality control information decoder and displaying the output image signal of the digital-analog converter.

Description

Apparatus for controlling video parameters of remote terminal in a video terminal

The present invention relates to an apparatus for controlling the image quality of a remote terminal in a video terminal.

Recently, the Integrated Services Digital Network (hereinafter referred to as ISDN) and the Broadband ISDN (B-ISDN) have been actively studied, and in the field of communication, a new service that can communicate video and data in addition to the existing voice communication service. The demand for is increasing. The most representative examples of this new service are "visual telephone" and "video conferencing system".

Recommendations from the International Telecommunication Unit-Telecommunication Standardization sector (hereinafter referred to as ITU-T) relating to video telephony and conferencing systems are given in Table 1 below.

Recommendation Contents H.320 Technical specification of narrowband audiovisual system H.242 Turn call on and off H.230 Control and Display Signals H.221 Multiplexing / Demultiplexing of Multimedia Information H.261 Video encoding

G.711 64 Kbps PCM Audio G.722 48,56,64 Kbps ADPCM audio G.728 16 Kbps audio I series Interface between terminal and network

In accordance with international cooperation for implementing video telephony and video conferencing and improvement of video signal compression technology, a standard as shown in Table 1 above could be proposed, and efforts to provide services by implementing the same have been continuously made.

As shown in FIG. 1, a general video terminal actually implemented according to the recommendation of the ITU-T includes an image input / output unit 102, an image compression and reconstruction unit 104, an audio input / output unit 112, an audio compression and The restoration unit 114, the data input / output and processing unit 120, the video camera remote control unit 132, the system control unit 134, the multimedia multiplexing and demultiplexing unit 140, and the communication network connection unit 150 are included.

Referring to FIG. 1, the video input / output unit 102 is a video camera or display apparatus of a video telephone or video conferencing system, and the image compression and decompression unit 104 displays an image input from the video input / output unit 102 in H.261. Compressed or decoded video data according to the standard and decode the video data received from the multimedia multiplexer and demultiplexer 140 according to the H.261 standard. The voice input / output unit 112 is a microphone or a speaker of a video telephone or a video conferencing system, and the voice compression and decompression unit 114 receives the voice data input from the voice input / output unit 112 in G.711, G.722, G. The compressed data according to the 728 standard or the voice data received from the multimedia multiplexing and demultiplexing unit 140 are decoded according to the G.711, G.722, and G.728 standards.

The data input / output and processing unit 120 is implemented as a protocol for transmitting image data other than video and audio (i.e. messages) according to the recommendations of the T.120 series. In other words, the T.120 standard is a standard for sharing whiteboard applications, file transfers, and various applications for video conferencing. .124 general control structure, etc.

Here, T.120 describes the general details of the data protocol for multimedia conferencing, T.121 is a template describing the general format, format, etc. of applications, and T.123 is an ISDN, POTS, LAN, ATM, etc. It expresses the function that can be connected according to the status of the lower network, and T.122 / 125 (MCS: Multipoint Communication Control) is a multilateral interactive based on the transport layer protocol (T.123) in the T.120 video conferencing structure. It supports multimedia conferencing applications. T.124 (GCC: Generic Conference Control) is a higher-level framework for managing real-time conferencing, video conferencing systems, and controlling MCS. It establishes and closes meetings, invites and leaves meetings, and participates in meetings. Provides management functions such as adding and removing nodes to the group. T.126 is a protocol that allows multi-user handling of still images in common areas in video conferencing, allowing each user to annotate.

The system controller 134 provides signaling, control and display functions defined by H.242 and H.230 protocols, and the video camera remote controller 132 executes the H.281 protocol based on H.224. To control the remote camera.

The multimedia multiplexing and demultiplexing unit 140 multiplexes and demultiplexes video, audio, and control streams according to the H.221 recommendation, and the network connection unit 150 provides a connection function with an actual communication network.

However, the conventional video terminal has proposed a structure for remotely controlling a video camera, but there is a problem in that a structure for controlling the image quality of a remote video terminal cannot be provided.

Accordingly, an object of the present invention is to provide a remote quality control apparatus capable of controlling the image quality of a remote video terminal in a video terminal in order to solve the problems of the prior art.

In order to achieve the above object, in the present invention, the transmission part compresses and encodes a voice signal and a video signal according to a predetermined protocol, and then multiplexes and transmits the same through a communication network. A video terminal which demultiplexes and decodes the signal according to a predetermined protocol, the output terminal comprising: a video camera; An analog-to-digital converter for converting the output of the video camera to digital; A captured image storage unit for storing image data of a predetermined size input through the analog-digital converter; An image compression unit compressing and encoding an image of the captured image storage unit; An image quality remote control unit outputting image quality control information in a predetermined format according to a user's control; A demultiplexer for multiplexing the output of the image compressor and the image quality remote control unit into a predetermined frame, wherein the receiving unit demultiplexes the received bit stream to separate the video stream and the image quality control stream; An image restorer for decoding the video stream output by the demultiplexer; A digital-analog converter for converting the reconstructed image into an analog signal; An image quality control information decoder configured to decode an image quality control stream output by the demultiplexer and output a control signal; And display means for adjusting an image quality related parameter value according to a control signal of the image quality control information decoder and displaying an output image signal of the digital-analog converter.

1 is a block diagram of a general video terminal proposed by ITU-T H.320,

2 is a schematic structural diagram of a video terminal according to the present invention;

3 is a block diagram illustrating transmission and reception of a video terminal according to the present invention.

4 is a view for explaining a remote quality control method according to the present invention.

* Explanation of symbols for main parts of the drawings

202: image input and output unit 204,210: image compression and restoration unit

212,220: voice input and output unit 214,222: voice compression and recovery unit

220: data input and output and processing unit 232: image quality remote control unit

234: system control unit 240: multimedia multiplexing and demultiplexing unit

250: communication network connection 301: video camera

302: analog-to-digital converter 303: capture image storage unit

304: image compression unit 305: multiplexer

310: image quality remote control unit 320: image quality control information decoder

331: demultiplexer

332: image restoration unit 333: restoration image storage unit

334: digital-to-analog converter 335: display device

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 2, the video terminal according to the present invention includes an image input / output unit 202, an image compression and reconstruction unit 204, an audio input / output unit 212, an audio compression and reconstruction unit 214, data input / output and The processor 220, the image quality remote control unit 232, the system controller 234, the multimedia multiplexing and demultiplexing unit 240, and a communication network connection unit 250 are included. In FIG. 2, the configurations except for the image quality remote control unit 232 are similar to those of the related art, and thus, further descriptions thereof will be omitted. The image quality remote control unit 232 will be described with reference to the embodiment of FIG. 3 and the data format of FIG. 4. Let's explain.

As described above, the embodiment of the present invention having the remote quality control function includes a transmission part A, a reception part B, and a transmission network 320, and the transmission part A is a video. The camera 301, the analog-to-digital converter 302, the captured image storage unit 303, the image compression unit 304, the multiplexing unit 305, the image quality remote control unit 310, the receiving portion (B) The demultiplexer 331, the image restorer 332, the restored image storage unit 333, the digital-analog converter 334, the display device 335, the image quality control information decoder 320, and the like.

Referring to FIG. 3, the video camera 301 captures the face of the conference attendee or the speaker, and the analog-to-digital converter (ADC) 302 converts and captures the analog image output from the video camera 301 into a digital image. The image storage unit 303 stores the image.

The captured image storage unit 303 is a video memory and forms a Common Intermediate Format (CIF) video format (ie, 352 x 288) of the H.261 standard.

The output image of the captured image storage unit 303 is compressed and encoded by the image compression unit 304 according to the H.261 standard, and then multiplexed by the multiplexer 305 and then the other side through the communication network connection and the transmission network 320, which are not shown. Is sent to.

Image quality remote control information by user control is input from the remote image quality control unit 310 to the multiplexer 305 and multiplexed according to the H.221 protocol. At this time, the image quality remote control information is multiplexed according to the format shown in FIG.

Referring to FIG. 4, the H.221 multiplexed frame is multiplexed with audio, video, LSD for remote control, MLP for T.120 series multimedia data transmission, and BAS data for system control. The LSD contains real-time remote control data in Q.222 (UI) frame.

Real-time remote control data consists of a flag, an address header, a control octet, an H.224 PDU, a frame check sequence (FCS), and a flag, and the H.224 PDU is a destination. To Terminal Address, Source Terminal Address, RES, Client ID, ES, BS, C1, C0, Segment Number, and Client Data Octets The quality control information is carried in this client data octet.

The client data octet includes the Client List Code, Response Code, number of clients, EX CAPS, Client ID, Client ID, and Client ID. ID).

In such a data format, when the control information for controlling the image quality of the remote terminal is inserted and transmitted, the reception unit receives the data stream and demultiplexes the multiplexer 331. The video stream separated by the demultiplexer 331 stores the reconstructed image decoded by the image restorer 332 according to the protocol of H.261 in the storage 333, and the image stored in the storage 333. Is converted into an analog signal by a digital-to-analog converter (DAC) 334 and then displayed on the display device 335. The audio stream is decoded through the audio decoder, not shown, and then output to the speaker.

In this case, the image quality control information is separated from the demultiplexer 331 and input to the image quality control information decoder 320, and the image quality control information decoder 320 receives the quality control information requested by the user according to the data format shown in FIG. Interpret The display device 335 transmits a control signal for controlling the image quality of the video parameter (eg, brightness, contrast, etc.) according to the image quality control information.

As described above, according to the present invention, it is possible to easily control the image quality of the remote terminal in a videoconferencing system or a video telephone, thereby providing a higher quality service.

Claims (1)

The transmitting part compresses and encodes the audio signal and the video signal according to a predetermined protocol, and then multiplexes and transmits it through a communication network. The receiving portion demultiplexes the received audio and video signal through the communication network and then decodes the signal according to a predetermined protocol. In the output video terminal, The transmitting part Video camera 301; An analog-to-digital converter 302 for converting the output of the video camera to digital; A capture image storage unit 303 for storing image data of a predetermined size input through the analog-digital converter; An image compression unit 304 compressing and encoding an image of the captured image storage unit; An image quality remote control unit 310 outputting image quality control information in a predetermined format according to a user's control; And a multiplexing unit 305 for multiplexing the output of the image compression unit and the image quality remote control unit into a predetermined frame. The receiving part A demultiplexer 331 for demultiplexing the received bitstream to separate the video stream and the image quality control stream; An image restorer 332 for decoding the video stream output by the demultiplexer; A digital-analog converter 334 for converting the reconstructed image into an analog signal; A quality control information decoder 320 for decoding a quality control stream output by the demultiplexer and outputting a control signal; And And display means (335) for adjusting image quality related parameter values according to the control signal of the image quality control information decoder and displaying the output image signal of the digital-analog converter.