JPH0715646A - Network camera - Google Patents

Abstract

PURPOSE:To provide a network camera which can freely select the angle of view and the shooting direction of a subject. CONSTITUTION:The video signals of the 1st and 2nd camera heads 103 and 117 are supplied to a video signal encoder 110 through a video signal bus 107 to undergo the data format conversion and coding processings. The coded video signals are sent to a network via an interface 111 which performs the protocol processing, etc. A control instruction given from a network is received by the interface 111 and transferred to a controller 109. The controller 109 stores the controlled variable of an actuator for each part at the relevant time point and outputs the difference between the controlled variable of the actuator and the control instruction value sent from the network as the drive value of the actuator. The network can control the directions of attaching angles, the focal distances, the focuses and the apertures of both camera heads and the positions and the intensity of the 1st and 2nd illuminators 105 and 106 respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera used in a high speed network capable of video communication and its control.

[0002]

2. Description of the Related Art Conventionally, a video camera has been used as a moving image input device in video conferences, video phones, and devices for making presentations using video images. Here, there is a document camera in which a television camera, lighting, a camera stand, and the like are integrated so as to be particularly convenient for presentations and meetings.

[0003]

A conventional document camera is
It is assumed that the presenter handles the camera while operating it directly. In particular, when performing a video communication with a distant place using a high-speed network capable of communicating a video signal, the conventional document camera has the following problems.

Since the presenter directly operates the camera, camera settings (eg, zoom and focus) are set in the document camera body.
The switches are installed, and the camera installation angle and lighting position cannot be changed or was set manually. Therefore, in the above-mentioned network conference, when the video receiver wants to focus on a part of the subject, the presenter is requested to zoom in the camera. Also, in a meeting showing a complex three-dimensional object, it is difficult to understand the shape only from the image seen from one side, so it is inevitable that the receiver side wants to change the camera position, angle, focus, etc. Often occurs.

Further, even when the receiver does not need the image, if the presenter keeps sending the image signal, the network channel is used more than necessary.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a network-compatible camera in which a receiver can freely select an angle of view and a shooting direction of a subject.

[0007]

In order to achieve the above object, a network-compatible camera according to the present invention has a plurality of camera heads according to claim 1, and a photographing condition of each camera head is externally controlled. Have means,
According to a second aspect of the present invention, the apparatus further comprises means for externally detecting a photographing condition of each camera head, and further, the third aspect of the present invention further comprises means for storing and returning a value indicating a performance peculiar to the camera. It is a thing. The shooting conditions of each camera head are as follows: shooting angle, distance between two camera heads, lens focal length, focus position, aperture amount, shutter speed of light receiving element, exposure timing of light receiving element, position of subject stage, position of illumination. , Which includes the amount of illumination, and the value that indicates the camera's unique performance includes the signal characteristics of the light receiving element, the characteristics of the color filter, the variable range of the focal length / focus / aperture of the lens, the color temperature of the illumination, and the flicker characteristics. It includes.

[0008]

The camera of the present invention has a plurality of camera heads, has a function of operating the state of each camera and lens from the network, and having a function of detecting the state of each camera / lens.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a block diagram of a network camera according to the present invention. In the figure, 101 is a subject, 10
2 is the subject stage, 103 is the first camera head, 1
04 is the second camera head, 105 is the first illumination, 10
6 is the second illumination, 107 is a video signal bus, 108 is a control signal bus, 109 is a system controller, 110 is a video signal encoder, and 111 is a network interface. Further, 112 is a stage drive unit, 113
Is a first head drive unit of the camera head, 114 is a first camera head focal length drive unit, 115 is a first camera head focus drive unit, 116 is a first camera head aperture amount drive unit, 117 is a second camera A head angle drive unit, 118 is a second camera head focal length drive unit, 119 is a second camera head focus drive unit, 120 is a second camera head aperture amount drive unit, 121 is a first illumination position drive unit, 12
2 is a first illumination intensity control unit, 123 is a second illumination position drive unit, 124 is a second illumination intensity control unit, and 125 is a ROM.
It's a table. Drive the mounting angle of 131 and 132
The detection unit handles at least two directions, and can be operated, for example, in the lateral direction within the paper surface and the direction perpendicular to the paper surface. The device is connected to a network through an interface 111 to communicate a video signal and a control signal.

Next, the operation of this apparatus will be described. First, the video signal has the following flow. The video signals of the first camera head and the second camera head are video signal bus 107.
Through the video signal encoder 110. This encoder performs conversion processing and coding into a data format for communication on the network. Further, this signal is transmitted to the network through the interface 111 which performs protocol processing and the like. Here, in normal use, the video signals of the two camera heads are coded and communicated as independent signals.
However, as shown in the figure, the encoder 110 is the controller 10
It is also possible to change the settings so that, for example, the signal of only the first camera head is transmitted and the signal of the second camera head is not transmitted, or vice versa. There is.

A control command for the camera head sent from the network is received by the interface 111 and passed to the controller 109. The controller 109 stores the actuator control amount of each unit at that time, and when a control command is sent from the net, outputs the difference from the command value as the actuator drive amount. In this example, all actuators are assumed to be of the type controlled by open loop such as stepping motors, but in the case of actuators controlled by closed loop, encoders are provided in each part and the values at that time are read from the control signal bus. It is configured to control afterwards. From the net, the two mounting angles of the camera heads, the focal length, the focus, the diaphragm, and the positions and intensities of the first illumination and the second illumination can be controlled.

This device can read out the control amounts, set values, device specifications of the device, that is, the shooting conditions of each camera head, from the network. For example, since the control amount of the actuator at that time is stored in the controller 109, it is read from here and transmitted. Information specific to the device, such as the variable range of the focal length of the lens, the mounting interval of each camera, the characteristics of the light receiving element, the minimum unit of the mounting angle drive, and the color temperature of the illumination system, are stored in the ROM table 12.
5, the data is read from the ROM table 125 and transmitted to the network.

Since the camera head of the present invention has such a structure, it is possible to realize the following new functions. FIG. 2 shows its usage. In the figure, 2
00 is a trunk network, 201 is a document camera of the present invention, 202 is a video camera, 203 is a presenter, 204, 206, 209 and 212 are the first, respectively.
2nd, 3rd, 4th displays, 205, 207, 2
Reference numerals 10 and 213 denote first, second, third and fourth joysticks for operating the display on the first, second, third and fourth displays, respectively. Further, 208 is an image coordinate conversion circuit, and 211 is an image composition circuit. In this figure, the video signal and the control signal are shown as being communicated on the same net, but they may be connected on different networks.

First, the first and second displays will be described. The first display 204 is the document camera 20.
Second display 206 of the first camera head of No. 1
Displays the images of the second camera head as they are. Each display is equipped with a joystick, and this operation makes it possible to control the mounting angle of the camera head, the focal length, and the focusing. Therefore, the receiver of the image can operate the joystick as desired to view the subject of the document camera at any angle and size. In this example, since only two camera heads are attached to the document camera 201, the number of recipients who can directly operate the camera heads is limited to two. Where the recipient is 3
There are cases where more than one person wants to view an image from a position different from that of the first and second displays. When this apparatus is used, the third image can be obtained without changing the states of the first and second camera heads. For example, the third display 209
An image coordinate conversion circuit 208 is attached to
The joystick is connected to this circuit. The coordinate conversion circuit 208 reads the state of each camera head and the video signal by communication, and detects the stereoscopic information of the subject.
Then, the receiver converts the image from the direction specified by the joystick, outputs the image, and displays the image on the third display. When there are two or more such camera heads, the technique of pseudo-converting the shooting direction of the subject is already known and realized. In this network, even if there are any number of displays on the reception side, if the coordinate conversion circuit is provided, it is possible to display at each photographing angle. Also, depending on the recipient, there is a case in which a particular point of interest is desired to be closed up to obtain detailed information. In a network using this device, when two camera heads are photographing the same portion in duplicate, that portion can be projected in high definition. For example, the fourth display includes an image synthesizing circuit 211, calculates the corresponding points of the overlapping portions of the images of the two camera heads, and superimposes the pixels of the corresponding two images to obtain the S / N ratio. Higher image quality can be obtained. Further, by instructing to shift the two camera head view angles by 0.5 pixel, it is possible to obtain image information with a fine pixel pitch apparently. As described above, in the document camera of the present invention, by providing the processing circuit on the receiver side, it is possible for a plurality of receivers to obtain one subject in any direction, size and image quality.

However, in the case of performing the coordinate conversion processing, the high definition of the overlapping portion, and the high S / N ratio processing, if the subject moves, the following points must be noted. For example, the image pickup device of each camera is a current TV system CCD image pickup device such as NTSC, and the field frequency is 60 Hz.
It is assumed that it is operating continuously. At this time, if the exposure start times of the cameras are deviated, that is, if the V-direction synchronization of the video signals is not the same, the respective cameras capture different states when the subject moves at high speed. At this time, the two images cannot be associated with each other, and the coordinate conversion process cannot be performed accurately. Moreover, when the images of the overlapping portion are overlapped, a blunt image or a blurred image results. Therefore, when performing such processing, the present apparatus can control the exposure time of each camera unit by an external command. When the exposure is performed periodically as in the current television system, the exposure time may be controlled only once. When the exposure cycle of each camera unit is different, the exposure start time, the exposure end time, and the read start time are independently controlled.

Furthermore, when each camera unit is exposed at the same field frequency, it is possible to use the system by intentionally shifting the V periods from each other. By doing so, the number of exposures per unit time can be apparently doubled. Therefore, when the subject has a fast movement, it is possible to suppress the shift of the image for each field to be small and to accurately grasp the movement state. In such a case, the difference between the exposure times of the camera units is read out or controlled from the network.

An error may occur in the detection value of the photographing condition of each camera unit in this apparatus due to mechanical mechanical play or electrical noise. For example, even if the focal length information read from each camera unit has the same numerical value, the respective image sizes may be slightly different. If the images are combined as they are, the images will still be blurred or blurred. Therefore, in a processing device that synthesizes images, for example, 208 and 211 in FIG. 2, the command value and the detection value of the shooting condition are calibrated using the image that is actually obtained.

In the above example, the number of camera heads is two, but when the number of camera heads is three or more, the stereoscopic information can be measured more accurately, and the range of the photographing direction to be converted is widened. Further, even when it is desired to obtain a high-definition image as in the case of the fourth display, if the number of camera heads is 3 or more, a finer image can be displayed. But,
These functions are peculiar to the camera of the present invention, because the above functions cannot be obtained at all by a document camera having only one camera head or a camera having two or more cameras that cannot be operated from the network.

The device further has the following functions. Figure 2
In the case where the second, third, and fourth displays desire the same video image and only display the video image, for example, when only the first camera head is required, the second video image is displayed. The video signal of the camera head uses a wasteful channel (band) on the network. Therefore, the document camera 201 does not transmit the signal of the second camera head to the network when there is no signal requesting the image of the second camera head. Therefore, the communication traffic of the network can be reduced to the minimum.

[0020]

As described above, the document camera of the present invention is provided with a plurality of camera heads, and is provided with a function of operating and detecting each camera head state from the network, so that a plurality of recipients can be detected. In a conference or presentation on the existing video network, the receiver can freely select the angle of view and shooting direction of the subject, and can realize more realistic video communication.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a document camera of the present invention.

FIG. 2 is a diagram showing an image pickup example of a document camera of the present invention in a video network.

[Explanation of symbols]

 101 Subject 102 Subject Stage 103 First Camera Head 104 Second Camera Head 105 First Illumination 106 Second Illumination 107 Video Signal Bus 108 Control Signal Bus 109 System Controller 110 Video Signal Encoder 111 Network Interface 112 Stage Drive Unit 113 First camera head angle drive unit 114 First camera head focal length drive unit 115 First camera head focus drive unit 116 First camera head aperture amount drive unit 117 Second camera head angle drive unit 118 Second Camera head focal length drive unit 119 Second camera head focus drive unit 120 Second camera head aperture amount drive unit 121 First illumination position drive unit 122 First illumination intensity control unit 123 Second illumination position drive unit 124 Second Brightness control section 125 ROM table 200 Main network 201 Document camera of the present invention 202 Video camera 203 Presenter 204 First display 205 First display operation joystick 206 Second display 207 Second display operation joystick 208 Image Coordinate conversion circuit 209 Third display 210 Third display operation joystick 211 Image combining circuit 212 Fourth display 213 Fourth display operation joystick

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideaki Mitsutake Inventor Hideaki Maruko 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Katsumi Iijima 3-30-2 Shimomaruko Ota-ku, Tokyo Canon Within the corporation

Claims (6)

[Claims] 1. A network-compatible camera comprising a plurality of camera heads, and means for externally manipulating photographing conditions of each camera head. 2. A network compatible device having a plurality of camera heads, having means for externally operating the photographing conditions of each camera head and means for externally detecting the photographing conditions of each camera head. camera. 3. A camera having a plurality of camera heads, means for operating the shooting conditions of each camera head from the outside, means for detecting the shooting conditions of each camera head from the outside, and a value indicating a performance peculiar to the camera is stored. A network compatible camera having means for transmitting and receiving. 4. A photographing condition of each camera head includes a photographing angle, a distance between two camera heads, a lens focal length, a focus position, an aperture amount, a shutter speed of a light receiving element, a position of a subject stage, a position of illumination, and an illumination amount. The network compatible camera according to claim 1, further comprising: 5. The value indicating the characteristic peculiar to the camera is a signal characteristic of a light receiving element, a characteristic of a color filter, a variable range of a focal length / focus / aperture of a lens, a minimum variable unit,
The network compatible camera according to claim 1, further comprising a response characteristic to a command, a color temperature of illumination, and a flicker characteristic. 6. A network-compatible camera, wherein shooting conditions of each camera head include exposure start time, exposure end time, and read time of an image sensor and a mutual time difference.