1. Field of the Invention
The present invention relates to a camera control system, and to a camera control method suitable for use with a system in which information communication is performed through a network, for example, a monitoring camera system or a television conference system.
2. Description of the Related Art
Conventionally, monitoring systems employing cameras have been used in comparatively small buildings. In such monitoring systems, a certain number of cameras are operated to form images of objects to be observed and the images in accordance with analog image signals output from the cameras are displayed on a plurality of monitor screens.
A camera control system has been proposed which can connect a plurality of cameras of a monitoring system of the above-described kind to a digital network such as a local area network (LAN) or to a public digital network such as an integrated service digital network (ISDN), and which enables a larger number of cameras in remoter places to be easily connected to the monitoring center.
For use in such a camera control system, a system has also been proposed in which a personal computer or a workstation is used as a camera operating terminal to perform camera control and image display with camera operations using a graphical user interface (GUI).
Such a graphical system has the advantage of enabling even a person unfamiliar with the control system to easily execute desired control operations. In particular, the facility of control can be improved by the method of displaying on a monitor screen a control panel of a camera along with the image output from the camera.
The method of displaying a control panel of a camera along with the image output from the camera on the monitor screen, however, entails a problem of a need to reduce the size of the image from the camera so as to leave a space for display of the camera control panel, as shown in
In view of the above-described problem, an object of the present invention is to provide a camera control system enabling an operator to intuitively control a camera while a large-area display of the image formed by the camera is provided.
To achieve the above-described object, according to one aspect of the present invention, there is provided a camera control system comprising display means for displaying an image formed by a camera on the basis of an image signal output from the camera, detection means for detecting a figure described on a display surface on which the image is being displayed by the display means, output means for outputting a command for controlling the camera on the basis of the figure detected by the detection means, control means for controlling the camera on the basis of the camera control command output from the output means.
According to another aspect of the present invention, there is provided a camera control apparatus comprising display means for displaying an image formed by a camera on the basis of an image signal output from the camera, detection means for detecting a figure described on a display surface on which the image is being displayed by the display means, and output means for outputting a command for controlling the camera on the basis of the figure detected by the detection means.
According to still another aspect of the present invention, there is provided a method of controlling a camera control system comprising a detection step of detecting a figure described on a display surface on which an image formed by a camera is being displayed, and an output step of outputting a command for controlling the camera on the basis of the figure detected in the detection step.
According to a further aspect of the present invention, there is provided a storage medium for storing programs for executing operational processings in a camera control apparatus, the storage medium being stored with programs for executing processings for displaying an image formed by a camera on the basis of an image signal output from the camera, detecting a figure described on a display surface on which the image is being displayed, and outputting a command for controlling the camera on the basis of the detected figure.
According to still a further aspect of the present invention, a camera control system comprises a monitor for displaying an image sensed by a camera, the displayed image corresponding to an image signal output from the camera. A detector is provided for detecting a gestural sign on a display surface on which the image is being displayed by said monitor. An interface is also provided for outputting a command for controlling the camera on the basis of the gestural signal detected by said detector. Finally, a controller controls the camera on the basis of the camera control command output from the output means.
These and other objects, features and advantages of the present invention will become apparent from the following description and the accompanying drawings.
A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.
To the image transmission terminals 12 (12-1 to 12-n), which function as camera servers, cameras 16 (16-1 to 16-n) are connected through camera controllers 14 (14-1 to 14-n). Each of the camera controllers 14 (14-1 to 14-n) controls pan, tilt, zoom and focusing of the corresponding one of the cameras 16 (16-1 to 16-n), with which it connects, in accordance with a control signal from the corresponding one of the image transmission terminals 12 (12-1 to 12-n).
The cameras 16 (16-1 to 16-n) are supplied with electric power from the camera controllers 14 (14-1 to 14-n). Each of the camera controllers 14 (14-1 to 14-n) performs on-off control of the corresponding one of the cameras 16 (16-1 to 16-n) in accordance with an external control signal.
To the network 10 are also connected image reception terminals 18 (18-1 to 18-m) which receive image information sent from the image transmission terminals 12 (12-1 to 12-n) into the network 10, and which display images formed by the cameras. To the image reception terminals 18 (18-1 to 18-m), which are client terminals, monitors 20 (20-1 to 20-m) constituted of bit-map displays, cathode ray tubes (CRTs) or the like are connected.
The network 10, which is not necessarily a wired network, may be a wireless network using wireless LAN apparatus. In such a case, image reception terminals 18 may be portable image reception terminals integral with monitors 20.
Each of the image transmission terminals 12 (12-1 to 12-n) compresses an image signal output from the corresponding one of the cameras 16 (16-1 to 16-n) in accordance with a predetermined compression system such as H.261, MPEG (Moving Image Experts Group) or Motion JPEG (Joint Photographic Experts Group), and transmits the compressed image signal to some of the image reception terminals 18 requesting the image or to all the image reception terminals 18. Each image reception terminal 18 is capable of controlling various parameters of the cameras 16 (shooting direction, image magnification, focus, aperture and so on) as well as power supply on-off control.
Each image transmission terminal 12 can also be used as an image reception terminal if a monitor is connected to it and if it is provided with an image expansion unit for expanding compressed images. On the other hand, each image reception terminal 18 can also be used as an image transmission terminal if camera controller 14 and camera 16 are connected to it and if it is provided with an image compression unit. In such case, these terminals are provided with read only memories (ROMs) for storing programs for executing image transmission and reception processings.
The image capture unit 36 of this embodiment has an A/D conversion function for converting an analog video signal into a digital signal, and an image compression function for compressing image information.
The image transmission terminal 12 also has a video board 38 for displaying image information on the screen of a monitor 40, a network interface 42, and a system bus 44 which connects the components 22 to 38, and 42 to each other. If the terminal 12 is provided as a unit for image transmission only, the video board 38 and the monitor 40 can be removed.
The thus-arranged image transmission terminal 12 transmits an image signal to some image reception terminal 18 in a remote place, receives a camera control signal transmitted from the image reception terminal 18, and executes control of pan, tilt and so on of the camera 16.
The image reception terminal 18 also has a pen type pointing device 130, which is used to input gestural signs described below on the screen of the monitor 140. A pressure sensor 150 is provided on the display screen of the monitor 140. The pressure sensor 150 detects a pressure when the display screen of the monitor 140 is pressed with the pen type pointing device 130, and transmits an address signal corresponding to a detected area to the CPU 122. The CPU 122 identifies a gestural sign described with the pen type pointing device 130 on the basis of a signal transmitted from the pressure sensor 150.
The pressure sensor 150 for detecting contact between the pen type pointing device 130 and the display screen is formed of transparent materials and the pressure detection system of the pressure sensor 150 may be of any type such as an electrostatic capacity type, a surface acoustic wave type, a resistance film type, or an infrared type. For example, if an electrostatic capacity system is used, contact with the panel surface can be recognized from a change in electrostatic capacity and the position of contact can be detected from changes in small ac currents supplied to the pressure sensor 150. Information on the state of contact, expressed as coordinate data, is supplied to the CPU 122 to identify a gestural sign described on the display screen.
The image reception terminal 18 has the same configuration as the image transmission terminal 12 shown in
The image reception terminal 18 transmits a camera control signal to one of image transmission terminals 12, and the image transmission terminal 12 controls the camera 16 in accordance with the content of the camera control signal and sends back information on the present status of the controlled camera 16. The image reception terminal 18 receives image data sent from the image transmission terminal 12, processes the data by predetermined kinds of processing and displays the image on the display screen of the monitor 140 in a real time manner.
Image reception software 52 is software for management of all the cameras 16 connected to the image transmission terminals 12 connected to the network 10. It includes fixed information and various kinds of changeable information of each camera 16 (e.g., a name of the camera, a host name or a name of the image transmission terminal 12 to which the camera 16 is presently connected, the state of the camera with respect to pan, tilt and zoom, possibility or impossibility of camera control, and identification of cameras 16 presently controlled by the terminal using this software or identification of cameras 16 from which displayed images are supplied). These kinds of information are also supplied to the camera control client 50 and to the map management software 54 and are used, for example, when the camera icon display is changed.
In the secondary storage 28 of each image transmission terminal 12 are stored a camera control server (software) 56 for controlling the camera 16 with the camera controller 14 according to a request from one of the camera control clients 50 and informing the requester of information on the present status of the camera 16 (the state of use of camera 16 and the like), and image transmission software 58 for compressing the output image from the camera 16 and transmitting the compressed image in a predetermined format to a requester through the network 10.
As shown in
A window 64 is an image display window having image display areas 66a to 66f, in which images from the cameras 16 are shown. The image display window 64 has a display mode for showing a plurality of image display areas, as shown in
In the camera control system of this embodiment, if there is a request for displaying an image formed by one of the cameras 16, a sequence of operations comprising selecting the icon representing the camera 16 on the corresponding map in the map window 60, superposing the icon on one of the image display areas 66a to 66f of the image display window 64 and releasing the icon in the superposed state (drag and drop) is performed. The image formed by the camera 16 is thereby displayed in the image display area onto which the icon has been dragged and dropped.
In operational processing in the image reception terminal 18 in this situation, the map management software 54 informs the image reception software 52 of the identity of the camera corresponding to the selected icon. The image reception software 52 finds, from this identity, the camera direction, the camera name and the name of the host to which the camera is connected. The image reception software 52 informs the camera control client 50 and the map management software 54 of these information items. The camera control client 50 and the map management software 54 execute the above-described operations on the basis of this control information.
If the above-described camera icon drag and drop operation is executed on one of the image display areas where an image is currently being displayed, a warning display is made to provide notice to the operator that the camera outputting the image will be changed, thereby enabling the operator to select or cancel the display of an image corresponding to a newly dragged and dropped icon in the image display area.
First, if clicking is performed on one of the image display areas 66a to 66f where an image from one of the cameras that the operator wishes to control is being displayed, then the above-described display windows are changed into a watch mode window such as shown in
In the watch mode, one image is displayed in an enlarged state. At this time, it is possible to select a frame rate priority display such that a displayed moving image can move smoothly, or an image quality priority display at high resolution, which is made by reducing the compression rate.
In step s101, after the display has been changed from the viewed mode to the watch mode, the camera control client 50 sends an inquiry signal to the camera control server 56 of the image transmission terminal 12, to which the camera 16 corresponding to the image displayed in the selected image display area is connected, to inquire whether or not the camera 16 is controllable.
Referring to
The image reception software 52 receives the camera status information in step s102 and then makes a determination in step s103 as to whether camera control with respect to pan and tilt or the like of the camera is possible from the received information on the present status of the camera 16.
If the result of the determination is that such camera control is possible, the image reception software 52 informs the camera control client 50 of this result and the camera control client 50 transmits a camera control signal to the camera control server 56 of the image transmission terminal 12. The camera control signal is formed by the operator in accordance with an operating method described below.
The camera control server 56 receives the camera control signal in step s203 and controls the operation of the camera 16 in accordance with the camera control signal in step s204.
If the result of the determination is that camera control is impossible, the image reception software 52 informs the camera control client 50 of this result and the camera control client 50 performs the control such that any control signal which may be input by the operator to execute a certain operation is ineffective.
In step s105, if the operator wishes to stop camera control, he or she may click a views button 82. The display window is thereby changed into watch mode windows such as those shown in
The method of controlling one of the cameras 16 forming an image displayed in the enlarged window in the watch mode as shown in
In this embodiment, in the case where an enlarged image is displayed in the watch mode, camera control is executed on the basis of a gestural sign which is described on the monitor 140 in a predetermined manner with the pen type pointing device 130, and which is detected by the pressure sensor 150 and is recognized by the CPU 122.
In this embodiment, the above-described pan and tilt control has a parameter variable according to the size (amount of stroke) of each kind of gestural sign.
In comparison between
While the pan and tilt control described above with reference to
If a gestural sign comprising a segment B and an arrowhead segment A is formed in such a manner, the CPU 122 determines the direction of pan or tilt according to the direction of arrowhead segment A in relation to the direction of segment B of the gestural sign detected by the pressure sensor.
The gestural sign shown in
Then, the CPU 122 transmits a control signal to the image transmission terminal 12 to perform panning and tilting so that the center of the circle described at a position on the image is positioned at the center of the window. Simultaneously, the CPU 122 transmits a signal for controlling the zoom ratio according to the size of the described circle to the image transmission terminal 12.
While pan, tilt and zoom control of camera 16 using a circularly described gestural sign such as that shown in
If such a rectangular gesture is made, the CPU 122 can definitely recognize the enlargement target area to accurately form commands for controlling pan, tilt and zoom of camera 16.
As shown in
The CPU 122 transmits a control signal to the image transmission terminal 12 to perform panning and tilting so that the point of intersection of the two segments forming “x” is positioned at the center of the window. Simultaneously, the CPU 122 transmits a control signal for reducing the zoom ratio according to the size of the described “x” to the image transmission terminal 12. In this embodiment, if the size of “x” is increased, the zoom ratio designated by the control signal is reduced.
In step s10, an input gesture is normalized on the basis of the signal representing the result of detection made by the pressure sensor 150. Next, in step s11, the normalized input gesture pattern is collated with gesture patterns previously stored in the external storage 126 (with respect to processing relating to the gesture and the stroke of the gesture).
If collation in step s12 ends in failure, no processing is performed thereafter and the process ends. If collation in step s12 ends in success, a control command (for pan, tilt, zoom or the like) corresponding to the collated gesture pattern is searched for in step s13. In step s14, some of various control parameters, which are the amount of panning movement, the amount of tilting movement, the zoom ratio and so on, is calculated from the size of the gesture pattern or the position at which the gesture pattern is formed.
For example, in pan and tilt control of camera 16 with respect to gestures such as those shown in
In step s15, a control signal for executing control using some of the various parameters calculated as described above is transmitted to the image transmission terminal 12 through the network.
In this embodiment, normalization of an input gesture, the collation of the gesture pattern and search for a corresponding control command, and camera control in accordance with the control command found by searching are executed on the image reception terminal 18 side. However, the arrangement may alternatively be such that the input gesture signal is immediately transmitted from the image reception terminal 18 to the image transmission terminal 12 and the above-described operational processing is performed in the image transmission terminal 12.
This operation method can easily be practiced in such a manner that a control program for executing the above-described operational processing is stored in the secondary storage 28 or the external storage 26, and the CPU 22 reads out the control program to the main storage 24 and executes the camera control processing in accordance with the program.
As described above, the camera 16 corresponding to a displayed image can easily be controlled by performing a gestural operation on the screen of the monitor 140 with the pen type pointing device 130. If this camera control is performed, the need for provision of an operation panel for camera control on the screen of the monitor 140 is eliminated, so that the image formed by the camera can be displayed without being obstructed by the operation panel, that is, the image display area can be enlarged by the amount corresponding to the operation panel area.
According to the above-described embodiment of the present invention, the arrangement may alternatively be such that a recording medium on which program codes of software for realizing the above-described functions is supplied to a system or unit, and this system or unit (CPU, MPU or the like) reads out the program codes stored in the storage medium and executes processings in accordance with the program codes.
In such a case, the program codes themselves realize the functions of the embodiment described above, and the storage medium storing the program codes constitutes this embodiment.
The storage medium used to supply program codes may be, for example, a floppy disk, a hard disk, an optical disk, an magneto-optical disk, a compact disk read only memory (CD-ROM), CD-Recordable, a magnetic tape, nonvolatile memory card, or a read only memory.
The method for realizing the functions of the above-described embodiment by executing processing in accordance with program codes read out by a computer may also comprise performing a part or the whole of the actual processing with an operating system or the like running on the computer in accordance with instructions of the program codes.
Further, after the program codes read out from the recording medium have been written to a feature expansion board inserted in the computer or to a memory provided in a feature expansion unit inserted in the computer, a CPU or the like provided in the feature expansion board or unit performs a part or the whole of the actual processing in accordance with instructions of the program codes, thereby realizing the functions of the above-described embodiment.
If the above-described recording medium is used, the program codes corresponding to the above-described flowcharts are stored. Briefly, modules necessary for the camera control system of the present invention are stored in the storage medium.
According to the above-described embodiment of the present invention, at least program codes of a “normalization module” for normalizing an input gesture, a “collation module” for collating the gesture normalized by the normalization module with gesture patterns previously stored, and a “parameter calculation module” for calculating each of various control parameters from the size of the input gesture or the position of the gesture on the screen may be stored in the storage medium.
According to the embodiment of the present invention, as described above, it is possible to provide a camera control system which makes it possible to easily control pan, tilt or zoom of a camera through a network by performing a predetermined gestural operation on a display window while an image formed by the camera is being displayed in the display window, which requires no camera control operation panel on the screen of the monitor since such camera control is performed, and which therefore enables the image formed by the camera to be displayed by being fully enlarged over the monitor screen while enabling the desired camera control.
According to the embodiment of the present invention, it is also possible to provide an image receiving apparatus in which pan, tilt or zoom of a camera can easily be controlled through a network by performing a predetermined gestural operation on a display window while an image formed by the camera is being displayed in the display window, which requires no camera control operation panel on the screen of the monitor since such camera control is performed, and in which the image formed by the camera can therefore be displayed by being fully enlarged over the monitor screen while the desired camera control can be performed.
According to the embodiment of the present invention, it is also possible to provide a method of controlling an image receiving apparatus which makes it possible to easily control pan, tilt or zoom of a camera through a network by performing a predetermined gestural operation on a display while an image formed by the camera is being displayed in the display window, which eliminates the need for a camera control operation panel on the screen of the monitor by using the arrangement for such camera control, and which therefore enables the image formed by the camera to be displayed by being fully enlarged over the monitor screen while enabling the desired camera control.
According to the embodiment of the present invention, it is also possible to provide a storage medium for storing a control program which makes it possible to easily control pan, tilt or zoom of a camera through a network by performing a predetermined gestural operation on a display while an image formed by the camera is being displayed in the display window, which eliminates the need for a camera control operation panel on the screen of the monitor by using the arrangement for such camera control, and which therefore enables the image formed by the camera to be displayed by being fully enlarged over the monitor screen while enabling the desired camera control.
While the present invention has been described with respect to what presently is considered to be the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment. To the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
Number | Date | Country | Kind |
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9-13943 | Jan 1997 | JP | national |
Number | Date | Country | |
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Parent | 09009932 | Jan 1998 | US |
Child | 11148290 | Jun 2005 | US |