JP4066288B2 - Automatic tracking device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic tracking device, and is suitable for application to an automatic tracking device that automatically tracks the optical axis of a video camera on a subject.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, video cameras used for video conferencing have been considered to have an automatic tracking function for automatically tracking the optical axis of a video camera with respect to a desired subject.
[0003]
FIG. 4 shows an audio tracking type automatic tracking camera 1 in which a camera unit 10 is mounted on a turntable 15 that is movable up and down and left and right. The voice tracking type automatic tracking camera 1 collects the voice of the speaker with the microphones 20A to 20D, calculates the azimuth difference between the optical axis of the imaging unit 23 and the speaker based on the phase difference of the voice, and based on this. By driving the turntable 15, the speaker is made to track the optical axis of the imaging unit 23.
[0004]
That is, in FIG. 5, the audio tracking type automatic tracking camera 1 amplifies the audio signals S20A to S20D supplied from the microphones 20A to 20D by the corresponding microphone amplifiers 21A to 21D, and sends them to the analog / digital converters 22A to 22D. . The analog / digital converters 22A to 22D convert the audio signals S20A to S20D from analog to digital and output them to the arithmetic unit 26. The computing unit 26 calculates the azimuth difference between the optical axis of the imaging unit 23 (FIG. 1) of the camera unit 10 and the speaker based on the phase difference between the audio signals S20A to S20D, and this is calculated as the azimuth signal S26 to the control unit 27. Output. The control unit 27 generates an X-axis drive signal S27X and a Y-axis drive signal S27Y based on the azimuth signal S26, and sends them to the X-axis motor 29X and the Y-axis motor 29Y included in the turntable 15. The X-axis motor 29X and the Y-axis motor 29Y rotate according to the X-axis drive signal S27X and the Y-axis drive signal S27Y so that the speaker can track the optical axis of the imaging unit 23.
[0005]
On the other hand, FIG. 6 shows the image tracking type automatic tracking camera 2, and the camera unit 11 is mounted on a turntable 15 that is movable up and down and left and right. The image tracking type automatic tracking camera 2 recognizes an image of a subject at the center of the captured image, and when the subject moves, the optical axis of the imaging unit 23 is changed by driving the turntable 15 according to the amount of movement of the subject. It is designed to track the subject.
[0006]
That is, in FIG. 7, the image tracking type automatic tracking camera 2 performs Y / C separation on the video signal S23 output from the imaging unit 23 in the Y / C separation circuit 24, and Y signals (luminance signals) S24Y and C signals (color difference signals). ) S24C is generated and sent to the analog / digital converters 25Y and 25C. The analog / digital converters 25Y and 25C perform analog / digital conversion on the Y signal S24Y and the C signal S24C, respectively, and output the result to the arithmetic unit 27. The calculation unit 26 recognizes the subject at the center of the screen imaged by the imaging unit 23 using the Y signal S24Y and the C signal S24C. When the subject moves, the calculation unit 26 calculates an azimuth difference between the optical axis of the imaging unit 23 and the subject, and outputs this to the control unit 27 as the azimuth signal S26. The control unit 27 generates an X-axis drive signal S27X and a Y-axis drive signal S27Y based on the azimuth signal S26, and sends them to the X-axis motor 29X and the Y-axis motor 29Y included in the turntable 15, respectively. The X-axis motor 29X and the Y-axis motor 29Y rotate according to the X-axis drive signal S27X and the Y-axis drive signal S27Y, thereby tracking the optical axis of the imaging unit 23 to a desired subject. When the subject moves so as to approach or move away from the image tracking type automatic tracking camera 2, the control unit 27 sends a zoom signal S27Z to the imaging unit 23 in response to the zooming.
[0007]
[Problems to be solved by the invention]
However, voice tracking has low tracking accuracy in principle, and it is difficult to reliably track a speaker when the camera is zoomed in. On the other hand, image tracking has a problem that when a speaker is replaced, it is impossible to track a new speaker.
[0008]
The present invention has been made in consideration of the above points, and intends to propose an automatic tracking device capable of performing natural automatic tracking on a subject.
[0009]
[Means for Solving the Problems]
In order to solve such a problem, in the present invention, a sound collecting unit that collects sound emitted from a subject, a focal length input unit that inputs a focal length of the imaging device, and a focal length of the imaging device from a predetermined focal length threshold value Is smaller, the direction of the subject is calculated based on the sound collected by the sound collecting means, and based on the imaging signal output from the imaging means when the focal length of the imaging device is larger than a predetermined focal distance threshold Subject direction calculating means for calculating the direction of the subject and driving means for driving the optical axis of the imaging device in the direction of the subject based on the calculated subject direction are provided.
[0010]
By selecting and executing the audio tracking operation and the image tracking operation according to the focal length of the imaging device, natural automatic tracking can be performed on the subject.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0012]
In FIG. 1, reference numeral 3 denotes an automatic tracking camera as a whole, and a camera unit 12 is placed on a turntable 15 as driving means that can move up and down and left and right. As an audio tracking operation, the automatic tracking camera 3 collects the speaker's voice with the microphones 20A to 20D as the sound collecting means, calculates the direction of the speaker based on the phase difference of the collected voice, and based on this. By driving the turntable 15, the optical axis of the image pickup unit 23 is tracked to the speaker. Further, as an image tracking operation, the automatic tracking camera 12 recognizes an image of a subject at the center of the imaged screen, and when the subject moves, drives the turntable 15 according to the amount of movement of the subject, thereby The axis is tracked to a desired subject. Further, the automatic tracking camera 12 receives a zoom instruction signal and a table rotation instruction signal transmitted from the remote controller 40 as a focal length input means operated by the operator via infrared rays by the light receiving unit 32.
[0013]
That is, in FIG. 2 in which the same reference numerals are assigned to the common parts with FIGS. 5 and 7, the automatic tracking camera 12 amplifies the audio signals S20A to S20D supplied from the microphones 20A to 20D by the microphone amplifiers 21A to 21D, respectively. , And sent to the corresponding analog / digital converters 22A to 22D. The analog / digital converters 22A to 22D perform analog / digital conversion on the audio signals S20A to S20D and output them to the arithmetic unit 30 as subject direction calculation means. The Y / C separation circuit 24 performs Y / C separation on the video signal S23 output from the imaging unit 23 to generate a Y signal (luminance signal) S24Y and a C signal (color difference signal) S24C, which are analog / digital. Send to converters 25Y and 25C. The analog / digital converters 25Y and 25C perform analog / digital conversion on the Y signal S24Y and the C signal S24C, respectively, and output the result to the arithmetic unit 30.
[0014]
The calculation unit 30 performs a tracking operation determination process, which will be described later, and performs an audio tracking operation or an image tracking operation according to the zoom position of the imaging unit 23.
[0015]
In the voice tracking operation, the calculation unit 30 calculates the azimuth difference between the optical axis of the imaging unit 23 and the speaker based on the phase difference between the voice signals S20A to S20D, and outputs this to the control unit 31 as the azimuth signal S30. The control unit 31 generates an X-axis drive signal S31X and a Y-axis drive signal S31Y based on the azimuth signal S30, and sends them to the X-axis motor 29X and the Y-axis motor 29Y included in the turntable 15, respectively. The X-axis motor 29X and the Y-axis motor 29Y rotate according to the X-axis drive signal S31X and the Y-axis drive signal S31Y, thereby causing the speaker to track the optical axis of the imaging unit 23.
[0016]
On the other hand, in the image tracking operation, the calculation unit 30 recognizes the subject at the center of the screen imaged by the imaging unit 23 using the Y signal S24Y and the C signal S24C. When the subject moves, the calculation unit 30 calculates the azimuth difference between the optical axis of the imaging unit 23 and the subject, and outputs this to the control unit 27 as the azimuth signal S26. The control unit 27 generates an X-axis drive signal S27X and a Y-axis drive signal S27Y based on the azimuth signal S26, and sends them to the X-axis motor 29X and the Y-axis motor 29Y included in the turntable 15, respectively. The X-axis motor 29X and the Y-axis motor 29Y rotate according to the X-axis drive signal S27X and the Y-axis drive signal S27Y, thereby tracking the optical axis of the imaging unit 23 to a desired subject. When the subject moves so as to approach or move away from the automatic tracking camera 12, the control unit 31 sends a zoom signal S31Z to the imaging unit 23 in response to the zooming.
[0017]
FIG. 3 shows the tracking operation determination process. The control unit 31 starts the process at step SP1, and determines whether or not the turntable 15 and / or the zoom mechanism of the imaging unit 23 are stopped at step SP2. If a negative result is obtained in step SP2, this indicates that the turntable 15 and / or the zoom mechanism of the imaging unit 23 are operating, and the control unit 31 returns to step SP2. On the other hand, when an affirmative result is obtained in step SP2, this indicates that the zoom mechanism of the turntable 15 and the imaging unit 23 is stopped, and the control unit 31 proceeds to step SP3.
[0018]
In step SP3, the control unit 31 obtains the zoom position of the zoom lens of the image pickup unit 23, that is, information on the current focal length as zoom information S23Z. In step SP4, the control unit 31 compares the zoom information S23Z with a predetermined zoom threshold. This zoom threshold is input in advance by the operator.
[0019]
If a negative result is obtained in step SP4, this indicates that the zoom information S23Z is smaller than the zoom threshold, that is, the zoom-out state, and the control unit 31 proceeds to step SP5 and performs the audio tracking operation. Start. In step SP6, it is determined whether or not a zoom instruction signal from the remote controller 40 has been input. If a negative result is obtained in step SP6, this indicates that the zoom instruction signal is not input, and the control unit 31 returns to step SP5 and continues the audio tracking operation. If a positive result is obtained in step SP6, this indicates that a zoom instruction signal has been input, and the control unit 31 returns to step SP3.
[0020]
On the other hand, when an affirmative result is obtained in step SP4, this indicates that the value of the zoom information S23Z is larger than the zoom threshold, that is, the zoom-in state, and the control unit 31 proceeds to step SP7 and performs image tracking operation. To start. In step SP8, it is determined whether or not a table rotation instruction signal from the remote controller 40 has been input. If an affirmative result is obtained in step SP8, this indicates that a table rotation instruction signal has been input, and the control unit 31 returns to step SP7 to perform an image tracking operation on a new subject in the center of the screen. Start. On the other hand, if a negative result is obtained in step SP8, this indicates that the table rotation instruction signal has not been input, and the control unit 31 proceeds to step SP9 to determine whether or not a zoom instruction from the remote controller 40 has been input. Judging. If a negative result is obtained in step SP9, this indicates that a zoom instruction has not been input, and the control unit 31 returns to step SP7 and continues the image tracking operation. If a positive result is obtained in step SP9, this indicates that a zoom instruction signal has been input, and the control unit 31 returns to step SP3.
[0021]
Thus, the control unit 31 performs an audio tracking operation or an image tracking operation in accordance with the zoom position of the imaging unit 23, the zoom instruction signal, and the table rotation instruction signal.
[0022]
In the above configuration, the control unit 31 executes either the audio tracking operation or the image tracking operation according to the zoom position of the imaging unit 23. When the imaging unit 23 is in the zoom-out state, the control unit 31 starts an audio tracking operation and controls the X-axis motor 29X and the Y-axis motor 29Y so that the optical axis of the imaging unit 23 faces the speaker. In this state, when a zoom instruction signal is input from the remote controller 40, the control unit 31 again selects either the audio tracking operation or the image tracking operation according to the zoom position of the imaging unit 23.
[0023]
When the imaging unit 23 is zoomed in, the control unit 31 starts an image tracking operation, and controls the X-axis motor 29X and the Y-axis motor 29Y so that the optical axis of the imaging unit 23 is directed toward the subject at the center of the screen. In this state, when a table rotation instruction signal is input from the remote controller 40, the control unit 31 controls the X-axis motor 29X and the Y-axis motor 29Y so that the optical axis of the imaging unit 23 is directed toward the new subject. In this state, when a zoom instruction signal is input from the remote controller 40, the control unit 31 again selects either the audio tracking operation or the image tracking operation according to the zoom position of the imaging unit 23.
[0024]
According to the above configuration, the operator inputs the zoom position of the imaging unit 23 using the remote controller 40, and the control unit 31 executes either the audio tracking operation or the image tracking operation according to the zoom position. As a result, natural automatic tracking of the subject can be performed.
[0025]
In the above-described embodiment, a plurality of microphones are provided in the automatic tracking camera. However, the present invention is not limited to this, and the microphones may be provided on the turntable.
[0026]
【The invention's effect】
As described above, according to the present invention, the sound collecting means for collecting the sound emitted from the subject, the focal length input means for inputting the focal length of the imaging device, and the focal length of the imaging device is lower than a predetermined focal length threshold value. If it is small, the direction of the subject is calculated based on the sound collected by the sound collecting means, and if the focal length of the imaging device is larger than a predetermined focal length threshold, the subject is based on the imaging signal output from the imaging means. The subject direction calculating means for calculating the direction of the image and the driving means for driving the optical axis of the imaging device in the direction of the subject based on the calculated direction of the subject are provided to perform natural automatic tracking on the subject. The obtained automatic tracking device can be easily realized.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an embodiment of an automatic tracking camera according to the present invention.
FIG. 2 is a block diagram showing an embodiment of an automatic tracking camera according to the present invention.
FIG. 3 is a flowchart showing a tracking operation determination process.
FIG. 4 is a schematic diagram showing a voice tracking type automatic tracking camera.
FIG. 5 is a block diagram showing an audio tracking type automatic tracking camera.
FIG. 6 is a schematic diagram showing an image tracking type automatic tracking camera.
FIG. 7 is a block diagram showing an image tracking type automatic tracking camera.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Voice tracking type automatic tracking camera, 2 ... Image tracking type automatic tracking camera, 3 ... Automatic tracking camera, 10, 11, 12 ... Camera part, 15 ... Turntable, 20A-20D ... Microphone, 23... Imaging unit, 30... Arithmetic unit, 31.

Claims (3)

In an automatic tracking device that tracks the optical axis of an imaging device whose focal length is variable to a predetermined subject,
Sound collecting means for collecting sound emitted from the subject;
A focal length input means for inputting the focal length of the imaging device;
When the focal length of the imaging device is smaller than a predetermined focal length threshold, the direction of the subject is calculated based on the sound collected by the sound collecting means, and the focal length of the imaging device is the focal length threshold. A subject direction calculation means for calculating the direction of the subject based on an imaging signal output from the imaging means when greater than,
An automatic tracking device comprising driving means for driving the optical axis of the imaging device in the direction of the subject based on the calculated direction of the subject. The said sound collecting means comprises a plurality of microphones, and the subject direction calculating means calculates the direction of the subject based on the phase difference of the sound collected by the plurality of microphones. Automatic tracking device. The automatic tracking device according to claim 1, wherein the subject direction calculation unit calculates the direction of the subject by recognizing the subject based on the imaging signal.

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