JPH08336122A - Remote conference device with automatic line disconnection function - Google Patents

Abstract

PURPOSE: To provide a function capable of safely disconnecting a line and a power source by judging leaving of a user. CONSTITUTION: This remote conference device comprises a camera A, an image encoder block B, a personal computer C, a communication control block D and a power source controller E. The line and the power source are disconnected by inputting code quantity information obtained in the coding of an image and the AF information of the camera to the personal computer C, comparing a prescribed condition with the present input value in advance, and judging the case that the condition is not satisfied for set continuous fixed time as leaving of the user.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion compensation mechanism or a measurement function incorporated as a basic function in a moving image communication device including a coding mechanism for compressing a moving image such as a video conference device and an in-person conference device. Utilizing the information output by the distance mechanism, without the need for a dedicated sensor for determining the presence or absence of the user, it is possible to determine that the user is absent and have a means for surely disconnecting the line or power supply. Related to the remote conference device.

[0002]

2. Description of the Related Art In a conventional device for performing a conference or moving image communication with a remote place represented by a videophone and a conference device, a user disconnects a line according to a predetermined procedure,
I had to turn off the main power to the device.

As for the means for judging leaving the seat,
An example of means for detecting the presence / absence of an operator near the device, other than the device for conducting a conference or moving image communication with a remote place,
It is described in JP-A-2-248147. The system described in this publication is a system for determining whether or not there is an operator of a telephone relay stand by extracting a contour from an image captured by a camera and using image recognition means. If this method is adopted to realize the function of determining the presence of a remote conference, an image processing mechanism for contour extraction and an image recognition device for determining whether or not the operator is present are required. . Since these are not included in the basic functions of the moving image communication device, this means that a dedicated function must be added to determine the presence or absence of a user.

An example of means for detecting the presence / absence of an operator near a device other than a device for conducting a conference or moving image communication with a remote place has been disclosed in JP-A-2-288555 and Sho-63. No. 252055, JP-A-59-7
No. 2266, etc. The system described in this publication is a system that uses an ultrasonic sensor infrared sensor, an optical sensor, or the like to determine whether or not a telephone relay stand operator is present. If this method is adopted to realize the function of determining the presence of a teleconference, these sensors are required, and it is not included in the basic functions of the video communication device. It means that a dedicated function must be added to.

[0005]

In a conventional device for conducting a conference or moving image communication with a remote place represented by a videophone and a conference device, a user disconnects a line according to a predetermined procedure, Since the main power supply of the equipment had to be cut off, it was not possible to automatically disconnect the line or cut off the power supply.Therefore, communication costs increased due to forgetting to turn off the user, accidents due to overheating of equipment, etc. There was a risk.

[0006]

In order to solve the above-mentioned problems, in the teleconference device with the automatic leaving / disconnecting line disconnection function of the present invention, the presence or absence of the user at that time, that is, the state of leaving the user is displayed. A means for determining, a means for measuring the time for leaving the conference when the user has been away for a certain period of time, and a means for storing the ending process necessary before disconnecting the line and the power supply. And a means for performing (or executing) a termination process for disconnecting the line and the power according to the stored sequence, and it is possible to automatically perform the necessary procedure for disconnecting the line and the power of the remote conference device. And

The means for judging the user's leaving state is originally performed by processing the data obtained from the function included in the remote conference device as a basic function, and the change over time or a preset value is set. It is realized by monitoring the difference between the value and the value. That is, the codec monitors the difference between the motion vector information, which is intermediate information generated at the time of encoding, and the inter-frame difference information, the change in the amount of information over time or a preset value, or the camera. In the case of a teleconferencing device that includes an automatic focal length adjustment mechanism, the distance measurement information of this camera is taken out and the presence or absence of a user is determined based on its temporal change or the difference from a preset value. It is possible to realize the function of controlling the disconnection of the line and the power without adding a dedicated detection mechanism.

If necessary, in the system for detecting the absence of the operator for the telephone relay stand, the means described in the publications cited in the section of the prior art may be used together or partially incorporated to further improve the apparatus. The judgment system may be enhanced, or the system configuration may be adapted to the site of use.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing the overall structure. First, regarding the flow of image information, the image captured from camera A enters image coding block B. The encoding block B digitizes the image information, performs a work to reduce the amount of the information, that is, compresses the information, and transmits the information to the communication circuit control block. From here, the communication line (mainly a telephone network or a digital communication network) is placed, and the information is transmitted to the communication partner.

FIG. 2 shows the image coding block B in FIG.
FIG. 3 is a block diagram showing in detail. The signal input from the camera A of FIG. 1 enters the capture circuit of B10. The capture circuit digitizes and captures the image.

The captured image information enters a quadrature converter B1 via a switch (which logically functions as a switch and can actually be composed of a semiconductor or software) B8. Generally, the operation performed in the orthogonal transformer is DCT (discrete cosine transform). Switch B
No. 8 is always switched for the first frame so that the information is guided from the video capture B10 to the orthogonal transformer B1 in the direction in which the intraframe coding is performed. For the subsequent frames and thereafter, the encoding control unit B3 monitors the information amount (the information path flowing from the subtractor B11 to the switch B8) obtained from the inter-frame difference and acquires the information from the video capture B10 or the subtractor B11. Then, the switch B8 is switched.

The signal output from the switch B8 is orthogonally transformed by the orthogonal transformer B1 and supplied to the quantizer B2. The quantizer B2 quantizes information and reduces the amount of information at that time. In image coding, the information output by the quantizer B2, that is, the transform coefficient level B16, together with the inter-frame intra-frame identification flag B13, the transmission / non-transmission flag B14, the quantization characteristic information B15, and the motion vector information B
17 is encoded (generally digitized flag information and variable-length encoded conversion coefficient level B16 are put on a predetermined protocol defined by an international standard, such as H.261).
However, the parts from this point onward are not shown because they are not directly related to the explanation of the principle of the present patent.

The output of the quantizer B2 is also sent to the inverse orthogonal transformer B5 via the inverse quantizer B4, locally decoded by the adder B12, sent to the predictor B6, and video-captured by the subtractor B11. Only the difference of the information coming from B10 is passed to B8, and the information amount of the captured image is suppressed.

In the predictor B6, the local decoding signal of the output of the adder B12 obtained by the inverse conversion and the video capture B
Based on the information input from 10, the motion vector information B
Take out 17. Since the motion vector information is the information that describes the difference between the motions of the previous frame and the next frame, if the difference is large in nature (such as when there is a large moving object in the screen), The code amount increases. On the other hand, if there is little movement, the code amount decreases.

Therefore, by utilizing this property, it is possible to quantitatively capture the motion of the person in the image by monitoring the information amount B30 of the motion vector.

Further, since the predictor B6 holds the image information of the frame one frame before, that is, the local decoding signal, the local decoding signal and the information of the new frame obtained from the video capture B10 are directly input. , Compare with a comparator,
By obtaining the information on the difference, it is possible to know how the person in the image moved from the previous frame based on this information as the information difference between the newly captured frame and the previous frame. .

Although not shown, in many image coding apparatuses, the coding controller B3 generally includes a mechanism for monitoring the motion vector information amount B30. The motion vector information amount B is set in order to determine the selection condition for switching the switch B8 by performing coding control.
This is because the amount of information of the inter-frame difference information, which is 30 or equivalent, is required.

To explain the reason, if we touch on a general coding control method, the image obtained from the video capture B10 is compressed as it is, or the difference information obtained from the subtractor B11 is used. In order to determine which is more preferable, the condition is generally selected by monitoring the amount of motion vector and managing the amount of information generated here.

Here, the monitored motion vector amount B3
If 0 has a remarkably large value, it means that the frame has a low correlation with the previous frame. In this case, even if the output information of the subtractor B11 is used, the code amount can be effectively reduced. I can't contribute. Therefore, a selection is made to encode high-quality image information using information with few errors, that is, a selection is made to directly encode the image obtained from the video capture B10. Then, the encoding controller B3 controls the switch B8 to send information from the video capture B10 to the orthogonal transformer B1.

On the other hand, when the amount of motion vector is small, it means that the correlation with the previous frame is high, and the subtractor B1
The information amount of the difference information from the frame output by 1 is significantly smaller than the information amount of the frame directly captured from the video capture B10. Therefore, the difference information obtained from the subtractor B11 is encoded to select to increase the image compression efficiency. The coding controller B3 controls the switch B8 to send information from the subtractor B11 to the orthogonal transformer B1.

That is, since the coding controller B3 performs the coding control as described above, the motion vector information amount B30
It can be seen that the same information as is handled. Therefore, in order to obtain the information amount B30 of the motion vector, the internal information of the image encoding device can be utilized and a dedicated mechanism is not required.

The determination of leaving the seat is made by monitoring the information amount B30 of the motion vector. This information is input to the personal computer C. When monitoring the amount of information generated (equivalent to the amount of generated code), the image capturing of the teleconferencing system must be 30 frames / sec or less (because TV signals are handled, NTSC is 30 frames / sec or less, and PAL is 25 frames / sec. / Sec or less), and is generally 15 frames / sec or less, limited by the bandwidth of the transmission path.

Therefore, as the processing content, the comparison with the set numerical value is carried out by the interrupt processing of 30 times or less per second.
It is fully possible to be processed by the program in U, and it is not necessary to prepare special hardware for this.

Various methods are conceivable as the method of determining the leaving seat. For example, when a person is on the screen, the motion vector information B17 is always generated because it moves a little. In response to this, a value larger than a certain threshold should be output as the motion vector information amount B30. Therefore, when the motion vector information amount B30 continues to show a value smaller than the preset threshold value for a time longer than the preset time, it can be determined that the user has left the seat. Is.

That is, C on the personal computer
The program processed by PU reads the value of B30 with an I / O instruction (in the case of a memory-mapped I / O CPU, reads it as a memory read) at an interval interrupt of 30 times per second, and the value is preset. It is determined whether it is smaller than the threshold. If it is larger than the preset threshold value, the counter is cleared. If it is smaller, the counter is incremented, and then it is checked whether or not the count number of the counter exceeds a preset specified time. To give an example of the checking method, if the specified time is 1 minute and 30 seconds, for a system that checks at 30 times per second, 30 [times / second] × 9
When 0 [sec] = 2700 and the counter reaches 2700, it can be easily realized by activating a program that enters the termination process.

In the termination processing, in the case of a remote conference system capable of multipoint connection or data conference via a server system, logout (or various names such as logoff, leaving the conference, etc. depending on the system) is performed. Next, the line is disconnected (off-hook for telephone lines or ISDN, closed for networks such as LAN), and it is confirmed that these processes have been completed (even if it was done normally or if there was any abnormality). Then, after confirming that the line can be disconnected according to a predetermined protocol), a power-off signal is transmitted to the power control device E.

In the first embodiment, the method of reading the amount of information from the image code or the device for the determination of leaving the seat is to monitor the change in the amount of information with respect to the image of one screen of the currently displayed frame. In many cases, the image coding apparatus handles the data as a block (generally 8 × 8 pixels or 16 × 16 pixels) in a unit of performing orthogonal transformation. There is also a method of extracting information in block units and determining information in block units. The screen size of a general TV phone is 176
Although it is × 144 (QCIF), when divided by a block of 16 × 16 pixels, the parameter of the code amount obtained from one screen is 11 × 9 = 99 blocks, and about 99 numerical comparison operations are performed by the CPU. The calculation amount is such that it can be sufficiently processed within 1/30 seconds.

When handled in blocks, the person in the image is generally relatively in the center, so
It is possible to focus on the center and activate the end processing.

In the above embodiment, the case where the slight movement when the user is reflected in the screen can be continuously detected has been set as the seat, but when the user leaves the seat, the operation of leaving the person is not performed. Since it moves to the screen, the difference between frames increases once, and then there are no more people, so it becomes extremely small.

That is, once the generated code amount becomes large,
After that, when the generated code amount converges to a smaller value than before and the time has elapsed, it is possible to determine that the user has left and start the termination process.

Further, in the above embodiments, only the information obtained from the image coding apparatus is relied upon. However, when the camera A with an autofocus function is equipped as shown in FIG. The focus distance information can be obtained and used as information for the personal computer C to determine whether the user leaves the seat. If the installation location is decided, the distance measured when there is no person is saved in advance, the saved distance value is compared with the distance information currently obtained from the AF mechanism, and it is saved for a certain time or longer. If the distance value that is substantially equal to the given distance value continues, it can be determined that the user has left the seat. The method of measuring the fixed time can be the same as the method described in the first embodiment, that is, the method of counting by the interrupt processing of the CPU.

Alternatively, the distance value is saved in the presence of a person,
If the difference from the distance information currently obtained from the AF mechanism continues to deviate from a preset allowable value for a certain period of time or longer, it can be determined that the user has left the seat.

[0033]

INDUSTRIAL APPLICABILITY The present invention has a motion compensating mechanism and a distance measuring mechanism incorporated as basic functions in a moving picture communication apparatus including a coding mechanism for compressing a moving picture such as a video conference apparatus and an in-person conference apparatus. It is possible to provide a means for utilizing the information output by to determine that the user is absent and surely disconnect the line or power without the need for a dedicated sensor for determining the presence or absence of the user.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a remote conference device of the present invention.

FIG. 2 is a diagram showing a configuration example of an image coding block in FIG.

[Explanation of symbols]

 A camera B image coding block C personal computer D communication control block E power supply controller B1 orthogonal transformer B2 quantizer B3 coding controller B4 inverse quantizer B5 inverse transformer (orthogonal inverse transformer) B6 predictor B8 Switcher B9 Switcher B10 Capture circuit (video input circuit) B11 Subtractor B12 Adder

Claims (3)

[Claims] 1. In a teleconferencing system having a motion compensation mechanism between frames at the time of moving image coding, a means for extracting a motion vector value from a motion detection mechanism of the moving image coding mechanism, and a user's value from the vector value. A remote conference device with an automatic line disconnection function, which has a unit for determining the absence of a seat and a unit for detecting that a user has left the seat and has been absent for a certain period of time to disconnect the system line and power supply. 2. The apparatus according to claim 1, further comprising means for monitoring a code amount generated by the motion compensation mechanism from the moving image encoding mechanism, and determining a user's leaving by providing a fixed threshold value for the code amount. A remote conference device with an automatic line disconnection function. 3. The system according to claim 1 or 2, further comprising a camera having an autofocus (automatic focal length adjusting mechanism) function, and the means for detecting the leaving seat is means for taking out focal length information of the camera. A remote conferencing device with an automatic line disconnection function, which is equipped with an automatic line disconnection function and determines whether or not to leave the seat by monitoring the information.