Abstract:
An electronic apparatus includes a display and a data processor for processing data. First output circuitry outputs the data processed by the data processor to the display in order to display the data. An image pickup device picks up an object image and outputs motion-image data. Second output circuitry outputs to the display (i) the motion-image data output by the image pickup device, and (ii) control-window data for controlling the image pickup device. Preferably, camera pan and zoom icons are displayed on a computer display and may be used to pan and zoom a camera to place the camera moving image within an image display area on the same computer display.

Description:
This is a divisional application of Application No. 08/676,895, filed Jul. 8, 1996, now U.S. Pat. No. 5,793,367, which is a continuation of Ser. No. 08/175,869 filed Dec. 30, 1993 now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an electronic apparatus, and a control method therefor, and more particularly, to an electronic apparatus which is suitable for controlling image pickup means of the user and/or the communication partner (for example, in a video conference system), and a control method therefor. 
     2. Description of the Related Art 
     According to the provision of a digital and high-speed public communication network, it becomes possible to utilize a video conference system and a visual telephone system in which a moving image and a voice are simultaneously transmitted. 
     In a conventional video-conference or visual-telephone terminal, a camera for photographing meeting members or a speaker is mounted on a camera mount, so that panning, tilting, zooming, the control of the diaphragm and the like of the camera can be controlled using, for example, dedicated operation knobs on an operation panel of the user&#39;s apparatus. These functions can also be subjected to remote control by the communication partner&#39;s apparatus via a communication network. 
     In the above-described conventional configuration, however, the method of operating the operation knobs or the like is not related to the user&#39;s intuition and therefore is difficult to operate. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in consideration of the above-described problems. 
     It is an object of the present invention to provide an electronic apparatus which is easy to operate. 
     It is a further object of the present invention to provide a method of controlling an electronic apparatus which is easy to operate. 
     It is a still further object of the present invention to provide an electronic apparatus which is easy to operate and a method for controlling the apparatus when controlling image-pickup means. 
     It is still another object of the present invention to provide a new user interface for an image-pickup device. 
     It is still a further object of the present invention to provide an electronic apparatus having new functions. 
     It is yet another object of the present invention to provide an electronic apparatus which can perform a new type of control for an image pickup device. 
     According to one aspect, the present invention which achieves these objectives relates to an electronic apparatus comprising data processing means for processing data, first output means for outputting the data processed by the data processing means to display means in order to display the data, image pickup means for picking up an object image and for outputting motion-image data, and second output means for outputting motion-image data output by the image-pickup means and control-window data for controlling the image-pickup means to the display means. 
     According to another aspect, the present invention relates to a method for controlling an electronic apparatus including data processing means for processing provided data and output means for outputting the data processed by the processing means to display means in order to display the data, comprising the steps of generating motion-image data from image-pickup means, and outputting the motion-image data and control-window data for controlling the image pickup means to the display means. 
     According to still another aspect, the present invention relates to an electronic apparatus for controlling respective control factors for image pickup means generating a motion-image signal, comprising display means for displaying an image signal from the image pickup means on an image display area together with control icons for the respective control factors, pointing means for controlling the respective control icons, and control means for controlling the image pickup means in accordance with an operation of a control icon by the pointing means. 
     According to yet another aspect, the present invention relates to a method of controlling an electronic apparatus including image pickup means, comprising the steps of displaying an image signal from the image pickup means together with control icons corresponding to respective control factors for the image pickup means when controlling the respective control factors, and controlling the image pickup means in accordance with an operation of a displayed control icon. 
     According to still a further aspect, the present invention relates to an electronic apparatus including image pickup means, comprising means for assigning areas for an object assigned by pointing means on a display picture surface, calculation means for calculating an angle of rotation and an amount of zooming of the image pickup means for zooming an image within the areas in the display picture surface, and control means for controlling a rotation driving unit and a zooming driving unit of the image-pickup means in accordance with the calculated values. 
     The foregoing and other objects, advantages and features of the present invention will become more apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic diagram illustrating the configuration of a picture surface according to an embodiment of the present invention; 
     FIG. 2 is a diagram illustrating an external appearance of a terminal of the embodiment; 
     FIGS.  3 ( a ) through  5 ( b ) are diagrams illustrating the relationship between panning-control cursors and the angle of panning; 
     FIG. 6 is a format of a remote control command; 
     FIG. 7 is a block diagram illustrating a schematic configuration of the circuitry of video camera  40 ; 
     FIG. 8 is a block diagram illustrating a schematic configuration of a circuit for synthesizing a video signal and a computer image; 
     FIG. 9 is a block diagram illustrating a schematic configuration of another circuit for synthesizing a video signal and a computer image; 
     FIG. 10 is a block diagram illustrating a schematic configuration of a third circuit for synthesizing a video signal and a computer image; 
     FIG. 11 is a diagram illustrating an external appearance of a terminal, in which a microphone and a sound-volume control icon are added, according to another embodiment of the present invention; 
     FIGS. 12 through 14 are operational flowcharts in the second embodiment; 
     FIG. 15 is a flowchart of another routine for assigning panning, tilting and zooming; 
     FIG. 16 is a diagram illustrating the relationship between the focal length of the lens, the size and the angle of view of the image-pickup device; and 
     FIG. 17 is a diagram illustrating the size of camera-image display area  12 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Preferred embodiments of the present invention will now be described with reference to the drawings. 
     In an embodiment of the present invention, a moving image photographed by a camera is displayed on a window in an image display window system as a dedicated window (camera display/control window) for controlling the camera. Camera control cursors for panning, tilting, zooming, the diaphragm and the like of the camera are displayed on the camera display/control window. These cursors are assigned by one of various kinds of pointing devices (a mouse, a track ball and the like) or point input devices (a digitizer tablet, a touch panel and the like), and are moved on the picture surface. 
     A main-body CPU (central processing unit) controls panning, tilting, zooming, the control of the diaphragm or the like of the camera in accordance with the movement of the corresponding camera control cursor. The main-body CPU also functions as the CPU of a work station, a personal computer or the like, and therefore can perform various kinds of processing as in an ordinary computer. 
     FIG. 1 illustrates a camera display/control window of the embodiment. In camera display/control window  10 , camera-image display area  12  for displaying an image photographed by the camera is set, and panning-control cursor  14  and tilting-control cursor  16  are set below and at the right of camera-image display area  12 , respectively. Panning-control cursor  14  can freely move within the range of the horizontal width of camera-image display area  12 , and tilting-control cursor  16  can freely move within the range of the vertical width of camera-image display area  12 . 
     Panning-control cursor  14  allocates the range of panning of the video camera to be controlled within the movable range of the cursor, and is displayed at a position corresponding to the current angle of panning. Tilting-control cursor  16  functions in the same manner as panning-control cursor  14 . 
     Diaphragm-control cursor  18  is set at the right of tilting-control cursor  16 , and zooming-control cursor  20  is set at the right of diaphragm-control cursor  18 . These cursors can freely move in the vertical direction. The diaphragm is opened to a greater degree as diaphragm-control cursor  18  is located at a higher position, and the zoom magnification has a greater value as zooming-control cursor  20  is located at a higher position. 
     By moving these control cursors  14 ,  16 ,  18  and  20  in respective predetermined directions, the amounts of control of panning, tilting, the diaphragm and zooming of the camera are input to the main-body CPU. When displaying an image from the user&#39;s camera in camera-image display area  12 , the image is displayed while being inverted in the horizontal direction using a mirror-image forming circuit. When displaying an image from the communication partner&#39;s camera, the image is displayed without being inverted. 
     FIG. 2 is a front view illustrating an external appearance of a terminal. Main body  30  incorporates well-known circuit devices, such as a CPU board, a memory board, a floppy disk drive, a hard disk drive and the like. Camera display/control window  36  described with reference to FIG. 1 is displayed within full picture surface  34  of monitor  32 . The same reference numerals as those shown in FIG. 1 are indicated for the camera-image display area and the respective control cursors within camera display/control window  36 . By selecting video-camera-view icon  38 , the camera display/control window  36  is opened and displayed as shown in FIG.  2 . Although it is omitted from illustration a television-meeting icon, a document icon and the like are also displayed. 
     Video camera  40  is installed above monitor  32 . Video camera  40  incorporates a panning/tilting mount as well as video circuit and a video interface. 
     FIGS.  3 ( a ) through  5 ( b ) illustrate the corresponding relationship between the direction of panning of camera  40  and panning-control cursor  14 . FIGS.  3 ( a ),  4 ( a ) and  5 ( a ) are plan views of the terminal shown in FIG. 2 as seen from above, and FIGS.  3 ( b ),  4 ( b ) and  5 ( b ) illustrate positions of panning-control cursor  14  of camera display/control window  36 . 
     The user&#39;s video camera is controlled through the camera display/control window opened by the video-camera-view icon of the user&#39;s camera, and the communication partner&#39;s video camera is controlled through the camera display/control window opened by the video-camera-view icon of the communication partner&#39;s camera. 
     When controlling the communication partner&#39;s camera, the CPU within main body  30  transmits camera-control information to the communication partner&#39;s apparatus in a predetermined format. The CPU within the communication partner&#39;s apparatus performs panning and the like of the communication partner&#39;s camera in accordance with the received camera-control information. FIG. 6 illustrates a transmission format of such control information. The format includes an identifier indicating control information (“;” in the present embodiment), information relating to the apparatus to be controlled (3 bytes), the kind of operation command (2 bytes), an extension flag and an extender. 
     For example, as for the apparatus to be controlled, camera inputs #1 and #2 are represented by “V 11 ” and “V 12 ”, respectively. Information to identify respective apparatuses is represented by 3 bytes. The following operation commands are provided: 
     F0: setting of an automatic focus adjustment mode 
     F1: setting of a manual focus adjustment mode 
     F3: set the focus position to a farther position 
     F4: set the focus position to a nearer position 
     E0: perform automatic control of the diaphragm 
     E1: perform manual control of the diaphragm 
     E2: reduce the aperture value 
     E4: increase the aperture value 
     E0: designate the absolute value of the aperture value (utilizing the extender) 
     I0: request of initialization 
     S0: Request to return a status signal 
     Z0: setting of zooming up 
     Z1: setting of zooming out 
     Z2: move the zoom lens to the stored position (utilizing the extender) 
     Z5: move the zoom lens to the absolute position (utilizing the extender) 
     U0: panning to the right 
     U1: panning to the left 
     U2: tilt the camera upward 
     U3: tilt the camera downward 
     U4: direct movement to the stored position (utilizing the extender) 
     U5: designate the absolute angle of panning (utilizing the extender) 
     U6: designate the absolute angle of tilting (utilizing the extender) 
     The above-described commands represent an example, and the present invention is not limited to such commands. These operation commands may be set on the window of main body  30  of the terminal, or may be set through a keyboard connected to main body  30  of the terminal. 
     FIG. 7 illustrates the configuration of the internal circuitry of video camera  40 . Image pickup device  50  is driven by a clock signal generated by clock-signal generation circuit  52 , and converts an optical image passing through photographing lens  54  and diaphragm  56  into an electrical signal. Processing circuit  57  performs camera-signal processing, such as γ-conversion, color balance adjustment and the like, for the output of image pickup device  50 . Video encoder  58  converts the output of processing circuit  57  into a predetermined video format, for example, the NTSC format. The output of video encoder  58  is supplied from video output terminal  60  to main body  30 . 
     A camera control signal from main body  30  of the terminal is supplied to control circuit (CPU)  66  via control terminal  62  and interface  64 . Control circuit  66  controls panning-control motor  68  and tilting-control motor  70 , zoom lens  54   a  of photographing lens  54  via zooming control circuit  72 , and diaphragm  56  via diaphragm control circuit  74 . 
     Electric power necessary for these circuits is supplied from main body  30  to DC-DC converter  78  via power-supply terminal  76 . DC-DC converter  78  generates and supplies power-supply voltages necessary for the recpective circuits. 
     In the present embodiment, image pickup device  50 , clock-signal generation circuit  52 , photographing lens  54 , diaphragm  56 , control circuits  72  and  74  are installed on a movable mount. Panning-control motor  68  pans the movable mount, and tilting-control motor  70  tilts the movable mount. 
     Circuitry to synthesize an image represented by a non-interlacing signal, such as an output signal from a video camera or a television signal, with an image represented by an interlacing signal of a computer is well known. An example of such circuitry will be described. 
     FIG. 8 is a block diagram illustrating a schematic configuration of circuitry incorporated within main body  30 , in which a video signal from video camera  40  is superimposed on an internally generated image signal. An analog video (moving-image) signal conforming to NTSC/PAL/SECAM systems (or one of these systems) is input from video camera  40  to input terminal  100 . A/D converter  102  converts the analog video (moving-image) signal from input terminal  100  into a digital signal (moving-image signal). Video decoder  104  converts the output of A/D converter  102  into an RGB format, and supplies its output to synthesis control circuit  106 . PLL circuit  108  supplies a clock signal having a predetermined frequency to A/D converter  102 , video decoder  104  and synthesis control circuit  110 . 
     Data on bus  110  of main body  30  is supplied to synthesis control circuit  106  via buffer  112 . An address/control signal is directly supplied to synthesis control circuit  106 . Data, an address and a control signal on bus  110  of main body  30  are supplied to VGA-display-signal generation circuit  116  via bus interface  114 . VGA-display-signal generation circuit  116  generates image data in the VGA form of an image to be stored in memory  120  in accordance with a timing signal from timing-signal generation circuit  118 . The generated image data is supplied to synthesis control circuit  106  and color palette  122 . Color palette  122  outputs RGB image data in accordance with the data from circuit  116 . 
     Synthesis control circuit  106  writes the RGB data from video decoder  104  in video memory  124 , and generates a switching control signal for switch circuit  126  in accordance with the address/control signal from bus  110 . Switch circuit  126  selects one of the RGB data from color palette  122  and the RGB data from video memory  124  in accordance with the switching control signal, and outputs the selected data to D/A converter  128 . D/A converter  128  converts the digital data into an analog data. The synthesized image signal is supplied from output terminal  130  to monitor  32 , and the corresponding image is displayed on picture surface  34 . 
     FIG. 9 illustrates another example of circuitry to superimpose a video signal from video camera  40  on an image signal generated within main body  30 . An analog video signal from video camera  40  is input to input terminal  140 . A control signal, an address and data on the system bus of main body  30  are input to input terminals  142 ,  144  and  146 , respectively. Video digitizer circuit  148  digitizes the analog video signal from input terminal  140 , and supplies the digitized signal to arithmetic circuit  154 . An image signal generated by main body  30  is input to input terminal  150 , and synchronizing-signal generation circuit  152  generates a synchronizing signal in accordance with the image signal. 
     The control signal, the address and the data from input terminals  142 ,  144  and  146 , respectively, and the synchronizing signal from synchronizing-signal generation circuit  152  are input to arithmetic circuit  154 , which performs the following calculation in accordance with the synchronizing signal from circuit  152 . That is, arithmetic circuit  154  generates a switching signal for forming the image of the camera display/control window described with reference to FIG.  1  and for inserting an image obtained by changing the scanning rate of the output of circuit  148  in area  12  of the window. That is, arithmetic circuit  154  generates a switching signal between a signal representing a computer picture surface and a video signal. Arithmetic circuit  154  also writes image data generated by window control in video memory  156  in order to change the scanning rate of the output of circuit  148  using video memory  156 . The data stored in video memory  156  is read at a predetermined speed, and is converted into an analog signal by D/A converter  158 . 
     An image signal representing a computer picture surface from input terminal  150  is input to contact “a” of switch  160 , and the output of D/A converter  158  is input to contact b. A signal representing a picture surface from main body  30  of the terminal is input to input terminal  150 . Switch  160  is switched by the switching control signal output from arithmetic circuit  154 , and the output of switch  160  is supplied to monitor  32  of the main body of the terminal via output terminal  162 . 
     When displaying an image photographed by the user&#39;s camera, it is desirable to display the image while inverting the image in the horizontal direction from the viewpoint of the human sense. In the present embodiment, this is accomplished by inverting an image represented by a video signal from video camera  40  in the horizontal direction using a mirror-image forming circuit. In the circuitry illustrated in FIG. 10, a mirror-image forming circuit is added to the circuitry shown in FIG.  8 . Mirror-image forming circuit  164  is inserted between video decoder  104  and synthesis control circuit  106 , and is subjected to on/off control by data, an address and a control signal on bus  110 . That is, when mirror-image forming circuit  164  is turned on, the RGB image signal input from video decoder  104  is output while inverting the corresponding image in the horizontal direction. When mirror-image forming circuit is turned off, the RGB image signal input from video decoder  104  is output without being modified. Of course, when operating mirror-image forming circuit  164 , the relationship between the movement of panning-control cursor  14  in the horizontal direction and the direction of panning of the user&#39;s video camera  40  is inverted. 
     A microphone for voice input is indispensable in a video conference or a visual telephone. For example, as illustrated in FIG. 11, it is convenient if a directional microphone  170  is incorporated in video camera  40  and the direction of directional microphone  170  is changed in accordance with panning and tilting of video camera  40 . At that time, as shown in FIG. 11, sound-level control icon  172  is displayed within the camera display/control window. Camera-view icon  174  displaying the microphone is also used. 
     A description will now be provided of the operation of the present embodiment to perform remote control of the communication partner&#39;s video camera with reference to FIGS. 12,  13  and  14 . After turning on the power supply (step S 1 ), the setting of the communication partner&#39;s video camera to an initial position is requested by initialization command I 0  (step S 2 ). This setting includes, for example, the setting of the focus of the lens to a position to which the lens is most frequently focused. Thereafter, the apparatus of the present embodiment confirms completion of initialization of the communication partner&#39;s video camera by status return requenst command S 0  (step S 3 ). The loop of steps S 2  and S 3  is repeated until the initialization is completed (step S 4 ). 
     When the initialization has been completed, the main body of the terminal generates a computer display signal for monitor so that video-camera-view icon  38  (or  174 ) of the communication partner&#39;s camera is displayed on the user&#39;s monitor (step S 5 ). In response to the operation to open the icon  38  (or  174 ) (step S 6 ), the main body of the terminal controls video memory  156  and switch  160  (see FIG. 9) so that camera display/control window  10  (or  36 ) is set (step S 7 ). Camera display/control window  36  is thereby displayed on the monitor picture surface as shown in FIG. 2 (step S 8 ). 
     If there is an operation for camera display/control window  36  (step S 9 ), and if the operation is to close camera display/control window  36  (step S 10 ), camera display/control window  36  is closed, and the process returns to step S 6 . 
     If there is an operation for panning-control cursor  14  (step S 12 ), the process branches from step S 12  to step S 13 , in which the main body of the terminal calculates the panning angle of the communication partner&#39;s video camera in accordance with the new position of panning-control cursor  14 , and indicates the absolute panning angle by command U 5 . 
     If there is an operation for tilting-control cursor  16  (step S 14 ), the process branches from step S 14  to step S 15 , in which the main body of the terminal calculates the tilting angle of the communication partner&#39;s video camera in accordance with the new position of tilting-control cursor  16 , and indicates the absolute tilting angle by command U 6 . 
     If there is an operation for diaphragm-control cursor  18  (step S 16 ), the main body of the terminal calculates the stop value of the communication partner&#39;s video camera in accordance with the new position of diaphragm-control cursor  18 , and indicates the absolute stop value by command E 5  (step S 17 ). 
     If there is an operation for zooming-control cursor  20  (step S 18 ), the main body of the terminal calculates the zooming position of the communication partner&#39;s video camera in accordance with the new position of zooming-control cursor  20 , and indicates the absolute zooming position by command Z 5  (step S 19 ). 
     After steps S 13 , S 15 , S 17  and S 19 , the control state of the communication partner&#39;s video camera is requested by status-signal return request command SO (step S 20 ), and it is awaited until the desired control state is provided (step S 21 ). 
     Thereafter, it is checked if the user&#39;s apparatus is connected to the communication partner&#39;s apparatus (step S 22 ). If the result of the check is negative, the process returns to step S 9 . If the result of the check is affirmative, it is checked if a calling operation is being performed (step S 23 ). If the result of the check is affirmative, the process returns to step S 9 , and the processing and control corresponding to the user&#39;s operation are performed (steps S 9 -S 21 ). 
     When the calling operation has been completed, the process proceeds from step S 23  to step S 24 , in which it is checked if the user&#39;s apparatus is connected to the communication partner&#39;s line. If the result of the check is negative, the communication partner is again called (step S 25 ), and the processing after step S 9  is repeated. That is, by executing the above-described steps S 12 -S 21  after the user&#39;s apparatus has been connected to the communication partner&#39;s line, the communication partner&#39;s camera is controlled on the monitor of the user&#39;s terminal. 
     After the line connection has been completed, data of the functions of the user&#39;s camera and the communication partner&#39;s camera are exchanged (step S 26 ). After the data exchange has been completed, camera-view icon  38  (or  174 ) corresponding to the functions of the communication partner&#39;s camera is displayed on the monitor picture surface (step S 27 ). 
     After the meeting or conversation has ended, processing to terminate communication is executed. That is, if it is desired to disconnect the line (step S 30 ), the user instructs deletion of camera-view icon  38  (or  174 ) of the communication partner&#39;s camera by, for example, superimposing it on a refuse-bin icon as processing to disconnect the line (step S 31 ). The main-body CPU thereby determines that instruction to disconnect the line has been performed, and instructs a communication control circuit incorporated in or provided outside the apparatus to disconnect the line. After the line has been disconnected, the main-body CPU first flashes the camera-view icon of the communication partner&#39;s camera for a predetermined time period, and then erases it from the monitor picture surface. The process then returns to step S 9 , and start of the next communication is awaited. That is, in the present embodiment, communication can be disconnected only by erasing the microprocessor of the communication partner&#39;s camera. 
     In the present embodiment, the user&#39;s camera and the communication partner&#39;s camera can be intuitively operated by providing a graphical user interface. As a result, the operability of each camera is improved. Furthermore, since control icons are provided around a display image from the communication partner&#39;s camera, the communication partner&#39;s camera can be operated while watching the communication partner. 
     Alternatively, an arbitrary point within camera-image display area  12  shown in FIG. 2 may be selected, and the video camera to be controlled may be panned or tilted around that point. For that purpose, the relative coordinates of an assigned point within or outside camera-image display area  12  are calculated, the panning angle and the tilting angle are calculated from the calculated coordinate values. After confirming that the assigned point is within a movable range, the video camera to be controlled is rotatably driven by assigning the absolute values of the calculated angles. 
     In another approach, an arbitrary range within camera display/control window  10  and within or outside camera-image display area  12  may be selected, and panning, tilting and zooming of the video camera to be controlled may be integrally controlled so that an image within the selected range is fully displayed in camera-image display area  12 . For that purpose, the relative coordinates of a central point of the selected range within or outside camera-image display area  12  are calculated, control values for panning and tilting are calculated in the above-described manner, a zooming value for fully displaying the selected range in camera-image display area  12  is calculated, and panning, tilting and zooming of the video camera to be controlled are controlled in accordance with the calculated values. 
     FIG. 15 is a flowchart of a routine to realize the above-described operations. This routine may, for example, be inserted between any steps from step S 12  to step S 23 , preferably, between steps S 22  and S 23 . 
     The mouse is clicked for positions within camera-image display area  12  (steps S 41  and S 43 ), or the mouse is clicked while depressing the shift key for positions outside camera-image display area  12  but within camera display/control window  10 , for example, positions indicated by reference numerals  14  and  16  shown in FIG. 1, (steps S 41 , S 42  and S 43 ). By a dragging operation in the clicked state (step S 50 ), it is understood that the selection of the range has been assigned (step S 51 ). The assigned range is subjected to dicriminative display on the monitor picture surface using a frame, reversal display or the like. If an upper left portion of the selected range is subjected to double-clicking (step S 52 ), it is understood that the selection is released, and the discriminative display of the selected range is erased (step S 53 ). 
     If the clicking operation continues for at least a predetermined time period (step S 54 ), and if the shift key is depressed (step S 55 ), the camera to be controlled is zoomed out (step S 57 ). If the shift key is not depressed (step S 55 ), the camera to be controlled is zoomed up (step S 56 ). That is, by holding the mouse for a predetermined time period, the camera can be zoomed out or zoomed up after the necessary panning and tilting have been performed. 
     When the mouse has been subjected to double-clicking within camera-image display area  12  (steps S 41  and  43 ), or when the mouse has been subjected to double-clicking in the condition of depressing the shift key for a point outside camera-image display area  12  but within camera display/control window  10  (steps S 41 , S 42  and S 43 ), the panning angle α and the tilting angle β making the double-clicked position the center of a photographing operation are calculated (step S 44 ). If the calculated values indicate a region outside the movable range (step S 45 ), the fact is displayed and/or a warning is given using an image and/or voice (step S 46 ). 
     If the calculated values indicate a range within the movable range (step S 45 ), and if the double-click operation is performed for a point within the selected range (step S 47 ), an image within the selected range is zoomed up on the full picture surface (step S 48 ). If the double-clicking operation is performed for a point outside the selected range (step S 47 ), the camera to be controlled is panned and tilted for the calculated angles. 
     Next, the relationship between the focal length of the lens, the angle of view W and angle of rotation θ of the video camera will be briefly described with reference to FIG.  16 . The case of panning will be considered. If the horizontal width of the image pickup device is represented by Y, and the focal length of the photographing lens is represented by f, the following relationship holds: 
     
       
         tan  w=Y/ 2 f.   
       
     
     As shown in FIG. 17, if the horizontal width of camera-image display area  12  is represented by A, the horizontal distance between point P in camera-image display area  12  and point X designated by a mouse operation or the center of the selected range (α) is represented by “a”, and the necessary panning angle is represented by α, the following relationship holds: 
     
       
         tan α=( Y/ 2 f )×( a/A ). 
       
     
     The value α can be obtained from this expression. 
     The same kind of calculation can also be performed for the vertical direction. 
     Although the present invention has been described illustrating a video conference system, the present invention may, of course, be applied to a visual telephone, or a system to communicate or transmit a static image. 
     As will be easily understood from the foregoing description, according to the above-described embodiments, it is possible to control a video camera with a very simple and intuitive operation. 
     The individual components shown in outline or designated by blocks in the drawings are all well known in the electronic apparatus and the control method therefor arts and their specific construction and operation are not critical to the operation or best mode for carrying out the invention. 
     While the present invention has been described with respect to what is presently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. 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.