JPH09322136A - Image transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To select automatically a specific talker making a speech at present among a plurality of talkers in the image transmitter for a video conference system or the like. SOLUTION: The image transmitter having a communication control section making communication through the use of a telephone line, a digital signal processing section 5 compressing/expanding communication data, a video signal processing section 4 displaying a sent image or a received image, and a camera section 1 used for an input section of a transmission image and driven vertically and horizontally is provided with an image recognition means identifying image data from the camera section and the image recognition means applies recognition processing to the image data from the camera to specify one talker among a plurality of talkers so as to move the camera automatically in a direction of the specific talker.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still image transmission device,
The present invention relates to an image transmission device such as a moving image transmission device, a videophone, a video conference system, or the like.

[0002]

2. Description of the Related Art FIG. 7 shows a functional block diagram of a conventional image transmission apparatus. In the camera unit 101, reflected light from a subject passes through a lens 102 and is imaged on a solid-state image sensor (hereinafter referred to as CCD) 103. In the CCD 103, incident light is converted into an electric signal by photoelectric conversion, and is input to the video signal processing unit 104 as horizontal serial data of an image. The incident light here is processed into a luminance signal and a color difference signal, converted into a digital signal of several bits through an analog-digital (A / D) converter, and transferred to the digital signal processing unit 105.

The digital signal input to the digital signal processing unit 105 is encoded and written in the field memory as compressed data. The audio signal from the microphone 107 is also converted into a digital signal here and then encoded and written in the memory. Since the video data written in the field memory is displayed, it is transferred to the video signal processing unit 104 and at the same time transferred to the communication control unit 106 according to the intention of the user, and is transferred to the analog general line or I line.
It is transmitted to the communication partner through the SDN line.

The video data transferred to the video signal processing unit 104 is converted into an analog signal by a digital-analog (D / A) converter and then subjected to encoding processing and output as a composite signal to an external monitor. On the other hand, the video / audio data transferred to the communication control unit 106 is subjected to network control and protocol control of the analog general line or ISDN line, and the transmission is started.

The above is the flow of signals on the sender side of communication, and on the receiver side, the reverse process is followed. That is,
The video / audio data sent from the analog general line or the ISDN line is input to the digital signal processing unit 105 through the communication control unit 106. This received data is encoded compressed data. Digital signal processing unit 105
At the same time, the compressed data is written to the field memory and simultaneously decoded and transferred to the video signal processing unit 104, converted into an analog signal by a digital-analog converter and then converted into a composite signal by an encoding process, and then an external monitor. Is output to. The camera unit 10 used here
In No. 1, the camera is attached to the image transmission device or is connected to a commercially available camera device to perform photographing. Therefore, when changing the direction of the camera to a specific speaker among multiple speakers, there are some cameras that can be operated remotely by the attached camera, but commercially available cameras do not have a control line for remote operation, so they can be operated manually. All I could do was point the camera at a specific speaker. In any case, in the prior art, the camera lens unit is used until the specific speaker comes to the center of the monitor while manually or electrically checking the position of the speaker to check the position of the speaker for shooting the speaker of the conference. Was moving up, down, left and right.

[0006]

In the prior art, there is no choice but to adjust the camera position manually or electrically while looking at the monitor in order to photograph the talker during the conference. I couldn't concentrate. In addition, there is a problem that the resolution is lowered because only a method of extracting a specific speaker and electrically enlarging it can be performed.
The present invention has been made in view of the above problems, and provides an image transmission apparatus capable of automatically selecting a specific speaker who is currently speaking from a plurality of speakers.

[0007]

According to a first aspect of the present invention, there is provided a communication control unit for communicating using a telephone line, a digital signal processing unit for compressing / decompressing communication data, and a transmitted image or a received image. In an image transmission device including a video signal processing unit for displaying and a camera unit that can be driven vertically and horizontally to be used as an input unit for an image to be transmitted, image recognition means for identifying image data from the camera unit is provided. By recognizing the image data from the camera in the image recognition means, one speaker is specified from a plurality of speakers,
The invention is characterized in that the camera is automatically moved in the direction of a specific speaker. According to the invention of claim 2, in the invention of claim 1, the speaker is identified by the movement of the mouth. It is characterized by performing.

According to the above image transmission device, a specific speaker who is currently speaking can be automatically selected from a plurality of speakers in an image transmission device such as a TV conference system, so that a plurality of speakers are usually present. It is possible to proceed as efficiently as the conference.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a functional block diagram of an image transmission device according to the present invention. In the image transmission device of FIG. 1, first,
The image captured from the camera unit 1 is a solid-state image sensor (CC
After being converted into a luminance signal and a color difference signal by the video signal processing unit 4 via D) 8, analog-digital (A / D) conversion is performed and the result is input to the digital signal processing unit 5.

The digital signal input to the digital signal processing unit 5 is encoded and written in the field memory as compressed data. The audio signal from the microphone 7 is also converted into a digital signal here, and then encoded and written in the filled memory. The digital signal processing unit 5 mainly performs image feature extraction, motion vector detection, feature extraction image recognition processing, and the like, and also generates a rotation control signal for controlling rotation of the camera unit 1 and image memory control. And the image is compressed / decompressed. That is, although a plurality of speakers who have a meeting or a meeting are photographed in the video signal input from the lens 2 of the camera unit 1, the mouths of the plurality of speakers are extracted to determine whether or not they are currently moving. Then, the speaker with the most vigorous movement is specified from among the plural speakers. And
The specified speaker drives the electromagnet 3 of the camera unit 1 so as to be positioned at the center of the video signal from the lens 2 and changes the orientation of the camera. In other words, identify one from multiple speakers,
Automatic tracking is always performed so that the camera faces the specified person.

Here, the following motion vector detecting method is used to determine whether the speaker's mouth is moving. Motion vector detection methods are roughly classified into the following three methods. Representative point matching method A representative point is extracted from one of two images that are temporally continuous, the absolute value difference is calculated while shifting the position from the other image, and all representative points are added and accumulated.
The displacement amount that minimizes the cumulative value is determined as the one in which the two images have the highest correlation, and the displacement amount is obtained as a motion vector.

Gradient method A motion vector is obtained from two temporally continuous images by the ratio of the temporal gradient of the luminance value and the spatial gradient. This gradient method includes an iterative gradient method that simplifies the calculation and improves the detection accuracy by iterative calculation.

Phase Correlation Method A motion vector is obtained by utilizing the fact that the phase portion of the Fourier transform coefficient of two temporally consecutive images reflects velocity. This method requires a huge amount of calculation. Here, the circuit configuration is based on the representative point matching method.

The digitized image data from the camera section 1 is transferred to the communication control section 6 for line control as data compressed by the digital signal processing section 5 and transmitted through the public telephone line. It FIG. 2 is a block diagram showing the configuration of the motion vector detecting unit in the image transmitting apparatus, and FIG. 3 is a detailed block diagram of the motion vector detector used in the detecting unit. These Figure 2
In FIG. 3, 8 is a CCD, 9 is a CCD signal processing unit that processes a signal from the CCD 8, 10 is a motion vector detector that detects a motion vector based on a luminance signal from the CCD signal processing unit 9, and 11 is a center. A luminance signal obtained by processing the signal from the CCD 8 is converted into a digital signal through an A / D converter 12 in the motion vector detector 10, and then an odd field and an even field. Passing through the line interpolator 13 that corrects the positional deviation between the lines of the two-character low-pass filter (LP
The signal passed through F) 14 is sampled and recorded in the representative point memory 15 as a representative point. In the next field, the representative point line memory 1 is used as the representative point of the previous field.
6 and the absolute value difference between the luminance value of each pixel of the current field output from the low pass filter 14 is calculated by the absolute value difference circuit 17, and the difference is input to the adder 18 in the next stage. The output of the cumulative addition memory 19 is connected to the other input terminal of the adder 18, and the addition result is recorded in the cumulative addition memory 19. When this series of operations is executed over the entire TV scan, the cumulative addition memory 19 obtains a cumulative function corresponding to the two-dimensional address. After that, the address corresponding to the cell having the minimum value in the contents of the cumulative addition memory 19 is detected as a motion vector. Based on the detected motion vector, the central processing unit 12 identifies the speaker having the most motion every approximately one second. When the speaker is specified, the electromagnet 3 (see FIG. 1) attached to the camera is driven to control the speaker so that the speaker comes to the center of the image from the camera.

FIG. 4 shows an enlarged front view of the camera section, and FIG. 5 shows an enlarged side view of the camera section. Electromagnets 22, 23, 24 are provided inside the camera unit 21 that houses the lens 20 and in the rear and front of the camera unit 21. Further, the electromagnets 25 and 26 for driving the camera are arranged close to each other on the left and right of the camera unit 23, and the electromagnets 27 and 28 for driving the camera in the vertical direction are also arranged close to each other at the lower part of the camera unit 21. Has been done. In the initial state, no current is flowing in the coil portion of each electromagnet, and when the direction of the camera unit 21 is changed, it is controlled so that the current individually flows. For example, turn the camera unit 21 to the left (to the left toward the camera).
When changing to, a current is passed through the electromagnet 28. Then, the permanent magnet 22 at the front of the camera unit 21 is attracted, and the lens unit moves leftward. The rate of movement is controlled so that the speaker specified by the video signal from the lens comes to the center. For moving up and down, for example, when shooting an upward object, the current flowing through the electromagnet 27 on the front side of the bottom surface of the camera unit is reduced so that the rear portion of the camera unit portion 21 is lowered, so that the lens portion is raised. I will turn to the direction. When the lens portion is directed downward, the magnetic force of the electromagnet 28 on the rear side of the bottom surface of the camera is reduced by the opposite, and
By increasing the magnetic force of 7, the lens portion is directed downward.

FIG. 6 shows a detailed circuit block diagram of the image transmission apparatus of the present invention. In FIG. 6, 1 is the above-mentioned C
A camera unit including a CD, a lens, etc., 30 is a video output unit for outputting NTSC signals, 4 is the above-mentioned video signal processing unit, and CCD signal processing units 9, C for performing CCD signal processing
A motion vector detector 10 for detecting a motion vector from the signal from the CD signal processing unit 9 and an A / D for performing an A / D conversion process.
The D conversion unit 31, the encoder 32, and the D / A conversion unit 33 that performs D / A conversion on the signal from the encoder 32 are configured. Reference numeral 5 denotes the above-mentioned digital signal processing unit, which includes a memory control unit 34 for performing memory control, a buffer memory 35,
An image codec DSP 36, a buffer memory 37, an image memory 38, a camera drive control unit 39 for performing camera drive control, an image recognition unit 40 for performing image recognition, a microprocessor (CPU) 11, and the like. Reference numeral 6 denotes the above-mentioned communication control unit, which includes a dual port memory 41, a data selector 42, a serial / parallel conversion control unit 43 for performing serial / parallel conversion control, a line control controller 44, a microprocessor (CPU) 45, and the like. There is.

In this circuit, an output signal from the CCD of the camera section 1 is converted into a luminance signal and a color difference signal by the CCD signal processing section 4. Each signal is converted from an analog signal to a digital signal by the A / D converter 31 and recorded in the image memory 38. At this time, the luminance signal from the CCD signal processing unit 9 is transferred to the partial motion vector detector 10 and input to the microprocessor 11 as a motion vector. In the digital signal processing unit 5, the memory control unit 34 controls writing or reading of image data into the image memory 38.
Done by Further, the image code DSP 36 performs encoding / decoding of image data. At this time, efficient data transfer is performed by the buffer memories 35 and 37.

Further, in this circuit, the speaker is recognized by the image recognition unit 40 from the movement of the mouth of the person captured by the camera, and the camera drive control unit 39 controls the camera to follow the speaker. Be seen.

The signal from the CCD is the image memory 38.
Is recorded once, and when data is transferred to the line, the data is read from the image memory 38 and transferred to the image codec DSP 36 through the buffer memory 35, where the decoding process is performed and the communication control unit is executed again via the buffer memory 37. 6 is transferred. The received data from the communication line is decoded in the reverse flow, and the image memory 3
Written to 8.

In the above circuit, the microprocessor 1
1 controls a series of the above flows, and at the same time, selects a specific speaker from a plurality of speakers from the motion vector from the video signal processing unit 4, and performs camera drive control for moving the camera to the speaker. . Also, the decoded data from the digital signal processing unit 5 is converted to parallel data from serial data via the dual port memory 41 of the communication control unit 6 and transmitted to the general public line.

[0021]

According to the present invention, a specific speaker who is currently talking can be automatically selected from a plurality of speakers by an image transmission device such as a video conference system, and the camera automatically selects the specific speaker. Since it can be moved in the direction of the speaker, it is possible to proceed as efficiently as a normal conference in which a plurality of speakers are present.

[Brief description of drawings]

FIG. 1 is a functional block diagram of an image transmission device according to the present invention.

FIG. 2 is a block diagram showing a configuration of a motion vector detection unit in the device of the present invention.

FIG. 3 is a detailed block diagram of a motion vector detector in the device of the present invention.

FIG. 4 is an enlarged front view of a camera unit in the device of the present invention.

FIG. 5 is an enlarged lateral view of a camera unit in the device of the present invention.

FIG. 6 is a detailed circuit block diagram of the image transmission device of the present invention.

FIG. 7 is a functional block diagram of a conventional image transmission device.

[Explanation of symbols]

 1 camera section 2 lens 3 electromagnet for driving camera section 4 video signal processing section 5 digital signal processing section 6 communication control section 7 built-in / external microphone 8 solid-state image sensor (CCD) 10 motion vector detector 40 image recognition section

Claims (2)

[Claims] 1. A communication control unit for communicating using a telephone line, a digital signal processing unit for compressing / decompressing communication data, a video signal processing unit for displaying a transmitted image or a received image, and an image to be transmitted. In an image transmission device equipped with a camera unit that can be driven vertically and horizontally to be used as an input unit of, an image recognition unit for identifying image data from the camera unit is provided, and the image recognition unit recognizes image data from the camera. An image transmission device characterized in that one speaker is specified from a plurality of speakers by recognition processing, and the camera is automatically moved in the direction of the specified speaker. 2. The image transmission device according to claim 1, wherein the speaker is identified by the movement of the mouth.