Abstract:
A method of processing an image includes receiving an omnidirectional image. An instruction is received with a processor to process the omnidirectional image to generate a rectangular image, in response to user input via a display on the omnidirectional image. At least one intermediate image is generated showing a transition between the omnidirectional image and the rectangular image.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of co-pending U.S. application Ser. No. 13/980,422, filed Jul. 18, 2013, which is the U.S. National Stage of International Application No. PCT/JP2012/000366, filed Jan. 23, 2012, which claims priority to Japanese Application No. 2011-026766, filed Feb. 10, 2011. The contents of which are expressly incorporated herein by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a display device which displays video images and, more particularly, relates to a display device which displays video images captured by an omnidirectional camera. 
     BACKGROUND ART 
     Conventionally, a display device which displays a video image of an omnidirectional camera on a monitor is known. The omnidirectional camera generates a video image using a fish-eye lens having 360 degrees of a horizontal field of view, and therefore this video image (referred to as an “omnidirectional image” below) has a circular shape or a donut shape and has characteristics that distortion becomes significant at a position closer to an outer periphery. Hence, a conventional display device can display not only display an omnidirectional image which allows an entire image capturing range to be checked but also display an image (referred to as a “distortion corrected image” below) obtained by correcting distortion of a clipping range of entirety or part of the omnidirectional image. Further, this switching of display is based on a user&#39;s instruction. 
     Meanwhile, a display device which displays a video image of an omnidirectional camera is used in, for example, the following scenes. In a business scene, a mobile terminal such as a mobile telephone is used as a display device to display a video image of an omnidirectional camera installed at a construction site, a facility or a store. Further, when an omnidirectional camera is used as a monitoring camera, the omnidirectional camera is installed at a monitoring target site such as a railway platform or a parking lot, a video image of the omnidirectional camera is displayed at a headquarter or a central control room and is monitored by security guards. Furthermore, when a worker installs an omnidirectional camera which is used as a monitoring camera, at a high place such as a telegraph pole, an installation work business operator adjusts an angle of view while checking a video image of the omnidirectional camera using a display device of a wearable display type such as a wrist watch type. 
     When the display device is realized by a personal computer which has a monitor, an operation inputting means such as a mouse and a keyboard is provided, so that a user can instruct switching display by operating this operation inputting means (see, for example, Patent Literature 1 and Patent Literature 2). 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: Japanese Patent Application Laid-Open No. 11-136584 
     Patent Literature 2: Japanese Patent Application Laid-Open No. 2008-301034 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, when a small mobile terminal such as a mobile telephone is used as a display device as described above, the operation inputting means is physically restricted and an operation inputting means such as a mouse or a keyboard cannot be adopted unlike a conventional display device. In case of the display device which a worker who works at a high place wears as described above, the display device is made smaller and restrictions on the operation inputting means become more severe. 
     Further, even when physical restrictions are comparatively less like a display device installed at the above described headquarter or central control room, it is desirable to switch between display of an omnidirectional image and display of a distortion corrected image by a more intuitive operation without performing a complicated operation. 
     In light of the above problem, an object of the present invention is to provide a display device which can switch between display of an omnidirectional image and display of a distortion corrected image by a simple operation through an intuitive user interface. 
     Solution to Problem 
     In order to solve the conventional problem, a display device according to the present invention employs a configuration which includes: an image acquiring unit which acquires an omnidirectional image or a distortion corrected image obtained by correcting distortion of the omnidirectional image; a touch panel display unit which includes a panel interface; an operation detecting unit which, when the omnidirectional image or the distortion corrected image is displayed on the display unit, detects an operation which is directly performed with respect to a displayed image using the panel interface and which is directed to switching between display of the omnidirectional image and display of the distortion corrected image; and a display control unit which has the display unit displays the omnidirectional image or the distortion corrected image, and switches between the display of the omnidirectional image and the display of the distortion corrected image according to the operation detected by the operation detecting unit. 
     Another aspect of the present invention is a computer program, and this computer program is executed by a display device which has a touch panel display unit to cause the display device to function as the above display device. 
     Still another aspect of the present invention is a computer-implemented method in a device which has a touch panel display unit which includes a panel interface, and this method includes: a step of, when the omnidirectional image or the distortion corrected image is displayed on the display unit, detecting an operation which is directly performed with respect to a displayed image using the panel interface and which is directed to switching between display of the omnidirectional image and display of the distortion corrected image; and a step of switching between the display of the omnidirectional image and the display of the distortion corrected image according to the detected operation. 
     Advantageous Effects of Invention 
     The present invention enables a direct input of an operation of, when an omnidirectional image or a distortion corrected image is displayed on a touch panel display unit, switching display of the displayed image, so that it is possible to intuitively switch between display of an omnidirectional image and display of a distortion corrected image by a simple operation. 
     As described below, the present invention involves other aspects. Hence, disclosure of the present invention is intended to provide parts of the present invention and by no means limits the scope of the invention claimed herein. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram illustrating a configuration of a viewer terminal according to an embodiment of the present invention. 
         FIG. 2  is a block diagram illustrating a detail configuration of an image correcting sequencer according to the embodiment of the present invention. 
         FIG. 3( a )  is a view illustrating an omnidirectional image according to the embodiment of the present invention. 
         FIG. 3( b )  is a view illustrating a dragging operation of specifying a base line upon switching from an omnidirectional image to a panoramic image according to the embodiment of the present invention. 
         FIG. 3( c )  is a view illustrating a pinching out operation upon switching from an omnidirectional image to a panoramic image according to the embodiment of the present invention. 
         FIG. 3 ( d )  is a view illustrating an intermediate image upon switching from an omnidirectional image to a panoramic image according to the embodiment of the present invention. 
         FIG. 3( e )  is a view illustrating an intermediate image upon switching from an omnidirectional image to a panoramic image according to the embodiment of the present invention. 
         FIG. 3( f )  is a view illustrating a panoramic image according to the embodiment of the present invention. 
         FIG. 4( a )  is a view illustrating a panoramic image according to the embodiment of the present invention. 
         FIG. 4 ( b )  is a view illustrating an intermediate image upon switching from a panoramic image to an omnidirectional image according to the embodiment of the present invention. 
         FIG. 4( c )  is a view illustrating an omnidirectional image according to the embodiment of the present invention. 
         FIG. 5  is a flowchart illustrating switching from an omnidirectional image to a panoramic image and switching from a panoramic image to an omnidirectional image according to the embodiment of the present invention. 
         FIG. 6( a )  is a view illustrating an omnidirectional image according to the embodiment of the present invention. 
         FIG. 6( b )  is a view illustrating a tapping operation of specifying a clipped image according to the embodiment of the present invention. 
         FIG. 6( c )  is a view illustrating a pinching out operation of enlarging a clipped image according to the embodiment of the present invention. 
         FIG. 6( d )  is a view illustrating a dragging operation of moving a clipped image according to the embodiment of the present invention. 
         FIG. 6( e )  is a view illustrating a shaking operation of switching to a multiscreen according to the embodiment of the present invention. 
         FIG. 6( f )  is a view illustrating the multiscreen according to the embodiment of the present invention. 
         FIG. 7  is a view for explaining switching a single panoramic image to a double panoramic image according to the embodiment of the present invention. 
         FIG. 8( a )  is a view illustrating a pinching in operation of switching from a double panoramic image to a single panoramic image according to the embodiment of the present invention. 
         FIG. 8 ( b )  is a view illustrating an intermediate image upon switching from a double panoramic image to a single panoramic image according to the embodiment of the present invention. 
         FIG. 8( c )  is a view illustrating a single panoramic image according to the embodiment of the present invention. 
         FIG. 9( a )  is a view illustrating a flicking operation of scrolling a single panoramic image according to the embodiment of the present invention. 
         FIG. 9( b )  is a view illustrating scrolling of a single panoramic image according to the embodiment of the present invention. 
         FIG. 10( a )  is a view illustrating a flicking operation of scrolling a double panoramic image according to the embodiment of the present invention. 
         FIG. 10( b )  is a view illustrating scrolling of a double panoramic image according to the embodiment of the present invention. 
         FIG. 11( a )  is a view illustrating a modified example of an operation of scrolling a panoramic image according to the embodiment of the present invention. 
         FIG. 11 ( b )  is a view illustrating scrolling of a panoramic image according to the embodiment of the present invention. 
         FIG. 12 ( a )  is a view illustrating a pinching out operation of displaying a high quality image according to the embodiment of the present invention. 
         FIG. 12 ( b )  is a view illustrating display of a high quality image according to the embodiment of the present invention. 
         FIG. 12( c )  is a view illustrating a dragging operation of moving a clipping area of a high quality image according to the embodiment of the present invention. 
         FIG. 13( a )  is a view illustrating an omnidirectional image according to the embodiment of the present invention. 
         FIG. 13( b )  is a view illustrating a rotating operation of rotating an omnidirectional image according to the embodiment of the present invention. 
         FIG. 13( c )  is a view illustrating rotation of an omnidirectional image according to the embodiment of the present invention. 
         FIG. 14  is a view illustrating switching from an omnidirectional image to a panoramic image according to a first modified example of the embodiment of the present invention. 
         FIG. 15  is a view illustrating switching from an omnidirectional image to a panoramic image according to a second modified example of the embodiment of the present invention. 
         FIG. 16( a )  is a view illustrating a dragging operation of panoramic expansion according to a third modified example of the embodiment of the present invention. 
         FIG. 16( b )  is a view illustrating a pinching out operation of panoramic expansion according to the third modified example of the embodiment of the present invention. 
         FIG. 17 ( a )  is a view illustrating a dragging operation of double panoramic expansion according to a fourth modified example of the embodiment of the present invention. 
         FIG. 17( b )  is a view illustrating a pinching out operation of double panoramic expansion according to the fourth modified example of the embodiment of the present invention. 
         FIG. 18 ( a )  is a view illustrating a pinching out operation (radial direction) of switching display of an omnidirectional image according to a fifth modified example of the embodiment of the present invention. 
         FIG. 18( b )  is a view illustrating a multi image including a clipped image according to the fifth modified example of the embodiment of the present invention. 
         FIG. 19( a )  is a view illustrating a pinching out operation (circumferential direction) of switching display of an omnidirectional image according to the fifth modified example of the embodiment of the present invention. 
         FIG. 19( b )  is a view illustrating a panoramic image according to the fifth embodiment of the embodiment of the present invention. 
         FIG. 20( a )  is a view illustrating a pinching out operation (vertical direction) of switching a single panoramic image to a double panoramic image according to a sixth modified example of the embodiment of the present invention. 
         FIG. 20( b )  is a view illustrating an intermediate image upon switching from a single panoramic image to a double panoramic image according to the sixth modified example of the embodiment of the present invention. 
         FIG. 20( c )  is a view illustrating a double panoramic image according to the sixth modified example of the embodiment of the present invention. 
         FIG. 21( a )  is a view illustrating a pinching out operation (horizontal direction) of switching a single panoramic image to a double panoramic image according to the sixth modified example of the embodiment of the present invention. 
         FIG. 21( b )  is a view illustrating an intermediate image upon switching from a single panoramic image to a double panoramic image according to the sixth modified example of the embodiment of the present invention. 
         FIG. 21( c )  is a view illustrating an intermediate image upon switching from a single panoramic image to a double panoramic image according to the sixth modified example of the embodiment of the present invention. 
         FIG. 21( d )  is a view illustrating a double panoramic image according to the sixth modified example of the embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, details of the present invention will be described. An embodiment described below is only an example of the present invention, and the present invention can be deformed in various modes. Hence, specific configurations and functions disclosed below by no means limit the claims. 
     A display device according to the embodiment of the present invention employs a configuration which includes: an image acquiring unit which acquires an omnidirectional image or a distortion corrected image obtained by correcting distortion of the omnidirectional image; a touch panel display unit which includes a panel interface; an operation detecting unit which, when the omnidirectional image or the distortion corrected image is displayed on the display unit, detects an operation which is directly performed with respect to a displayed image using the panel interface and which is directed to switching between display of the omnidirectional image and display of the distortion corrected image; and a display control unit which has the display unit displays the omnidirectional image or the distortion corrected image, and switches between the display of the omnidirectional image and the display of the distortion corrected image according to the operation detected by the operation detecting unit. 
     According to this configuration, a user can directly input an operation of, when an omnidirectional image or a distortion corrected image is displayed on a touch panel display unit, switching display of the displayed image, and, consequently, intuitively switch between display of an omnidirectional image and display of a distortion corrected image by a simple operation. In addition, the display device may further have a distortion corrected image generating unit which corrects distortion of part or entirety of the omnidirectional image, and generates a distortion corrected image. 
     In the above display device, when the omnidirectional image is displayed on the display unit and when the operation detecting unit detects that the omnidirectional image displayed on the display unit is pinched out, the display control unit may switch the display of the omnidirectional image to the display of the corrected image. 
     According to this configuration, pinching out of the omnidirectional image performed by the user and switching of display that the omnidirectional image is expanded and a distortion corrected image is displayed intuitively match, so that the user can more intuitively switch the display. 
     In the above display device, when the distortion corrected image is displayed on the display unit and when the operation detecting unit detects that the distortion corrected image displayed on the display unit is pinched in, the display control unit may switch the display of the distortion corrected image to the display of the omnidirectional image. 
     According to this configuration, pinching in of the distortion corrected image performed by the user and switching of display that the distortion corrected image is reversed to the omnidirectional image intuitively match, so that the user can more intuitively switch the display. 
     In the above display device, the distortion corrected image is a panoramic image obtained by performing panoramic expansion of the omnidirectional image based on a pinched out portion as a base line. 
     According to this configuration, pinching out performed by the user and switching of display of the omnidirectional image to display of a panoramic image intuitively match, so that the user can intuitively perform an operation of switching the display of the omnidirectional image to the display of the panoramic image by a simple operation. 
     In the above display device, the distortion corrected image may be a clipped image obtained by enlarging a pinched out portion. 
     According to this configuration, pinching out and display of the enlarged clipped image intuitively match, so that the user can intuitively perform an operation of displaying the clipped image by a simple operation. 
     In the display device, when the omnidirectional image is displayed on the display unit and when the operation detecting unit detects that the omnidirectional image displayed on the display unit is tapped, the display control unit has the display unit displays the distortion corrected image of a tapped portion of the omnidirectional image. 
     According to this configuration, tapping of the omnidirectional image performed by the user and display of the distortion corrected image of the tapped portion intuitively match, so that the user can intuitively perform an operation of displaying the distortion corrected image by a simple operation. 
     In the above display device, the display control unit may determine a correction parameter of an image based on the operation detected by the operation detecting unit, the display device may further have an intermediate image generating unit which generates an intermediate image displayed during switching between the display of the omnidirectional image and the display of the distortion corrected image, according to the correction parameter determined by the display control unit, and the display control unit may have the display unit displays the intermediate image generated by the intermediate image generating unit during the switching between the display of the omnidirectional image and the display of the distortion corrected image. 
     According to this configuration, the user can check switching process of display based on the intermediate image and, consequently, intuitively recognize the operation the user has performed and recognize the correlation between the display before switching and the display after switching. 
     A computer program according to the embodiment of the present invention is executed by a display device which has a touch panel display unit to cause the display device to function as the above display device. 
     A computer-implemented method according to the embodiment of the present invention is a computer-implemented method in a device which has a touch panel display unit which includes a panel interface, and includes: a step of, when the omnidirectional image or the distortion corrected image is displayed on the display unit, detecting an operation which is directly performed with respect to a displayed image using the panel interface and which is directed to switching between display of the omnidirectional image and display of the distortion corrected image; and a step of switching between the display of the omnidirectional image and the display of the distortion corrected image according to the detected operation. 
     According to this configuration, a user can directly input an operation of, when an omnidirectional image or a distortion corrected image is displayed on a touch panel display unit, switching display of the displayed image, and, consequently, intuitively switch between display of an omnidirectional image and display of a distortion corrected image by a simple operation. 
     In the above computer-implemented method, when the omnidirectional image is displayed on the display unit and when the omnidirectional image is pinched out, the display of the omnidirectional image may be switched to the display of the distortion corrected image. 
     According to this configuration, pinching out of the omnidirectional image performed by the user and switching of display that the omnidirectional image is expanded and a distortion corrected image is displayed intuitively match, so that the user can more intuitively switch the display. 
     In the above computer-implemented method, when the distortion corrected image is displayed on the display unit and when the distortion corrected image is pinched in, the display of the distortion corrected image may be switched to the display of the omnidirectional image. 
     According to this configuration, pinching in of the distortion corrected image performed by the user and switching of display that the distortion corrected image is reversed to the omnidirectional image intuitively match, so that the user can more intuitively switch the display. 
     In the above computer-implemented method, when the omnidirectional image is displayed on the display unit and when the omnidirectional image is tapped, the display unit may be caused to display the distortion corrected image of a tapped portion of the omnidirectional image. 
     According to this configuration, tapping of the omnidirectional image performed by the user and display of the distortion corrected image of the tapped portion intuitively match, so that the user can intuitively perform an operation of displaying the distortion corrected image by a simple operation. 
     Hereinafter, an embodiment for implementing the present invention will be described with reference to the drawings.  FIG. 1  is a block diagram illustrating a configuration of a viewer terminal which is a display device according to an embodiment of the present invention. The viewer terminal  1  includes a panel interface  11 , an operation detecting unit  12 , an image correcting sequencer  13 , an intermediate image generating unit  14 , a distortion corrected image generating unit  15 , an omnidirectional image acquiring unit  16 , an omnidirectional image decoding unit  17 , an image queue  18  and an image display unit  19 . In addition, the image display unit  19  and the panel interface  11  are overlaid and provided to form a touch panel display unit. 
     The panel interface  11  receives an operation inputted by user&#39;s fingers, and outputs information of an operation position. The operation detecting unit  12  receives the information of the operation position from the panel interface  11  and, when a panel operation is changed, detects content of the panel operation performed by the user based on content of the change. Operations performed by the user&#39;s fingers with respect to the panel interface  11  include tapping, dragging, flicking, pinching (pinching out and pinching in) and rotation. 
     Tapping refers to an operation of lightly hitting a portion of the panel interface  11  by one finger, that is, an operation of touching the panel interface  11  by one finger and separating the finger from the panel interface  11  without moving the finger on the panel interface  11 . Dragging refers to an operation of dragging the finger on the panel interface  11 , that is, an operation of moving one fingertip in contact with the panel interface  11 , stopping movement of the finger and separating the finger from the panel interface  11 . Flicking refers to an operation of flipping the panel interface  11  by the finger, that is, an operation of moving one fingertip in contact with the panel interface  11  and separating the finger from the panel interface  11  without stopping movement of the finger. 
     Pinching out refers to an operation of moving one or both of two fingertips on the panel interface  11  keeping the two fingertips in contact with the panel interface  11  such that a distance between the fingers becomes far. By contrast with this, pinching in refers to an operation of moving one or both of the two fingertips on the panel interface  11  keeping the two fingertips in contact with the panel interface  11  such that a distance between the fingers becomes close. Rotation refers to an operation of moving one or both of the two fingertips on the panel interface  11  keeping the two fingertips in contact with the panel interface  11  such that a line segment connecting the fingers rotates in a plane of the panel interface  11 . 
     In addition, operations performed by user&#39;s fingers may include, for example, double tapping and long tapping in addition to the above. Further, when an electronic compass is built in the viewer terminal  1  and can detect an acceleration (posture) of the viewer terminal  1 , the user may input an operation by shaking or tilting the viewer terminal  1 . In this case, when the acceleration of the viewer terminal  1  changes, the operation detecting unit  12  detects a user&#39;s operation based on content of this change. 
     The image sequencer  13  determines correction parameters (such as a center coordinate, a range, rotation and distortion) of an image to be generated and displayed next, according to content of a panel operation to have the image display unit  19  display the image and switch between display of an omnidirectional image, display of an intermediate image and display of a distortion corrected image (the distortion corrected image includes a panoramic image and a clipped image.). The correction parameters are parameters used to correct an omnidirectional image. By applying the correction parameters to an omnidirectional image, a distortion corrected image or an intermediate image is generated. The image correcting sequence  13  corresponds to the display control unit according to the present invention. 
     The intermediate image generating unit  14  generates an intermediate image upon switching from an omnidirectional image to a distortion corrected image or from a distortion corrected image to an omnidirectional image. The intermediate image is an image displayed during switching. The intermediate image generating unit  14  generates an intermediate image matching content of a panel operation based on the correction parameters inputted from the image correcting sequencer  13 . The intermediate image generating unit  14  generates a plurality of intermediate images where necessary to show that switching from an omnidirectional image to a distortion corrected image or from a distortion corrected image to an omnidirectional image is performed stepwise. 
     The distortion corrected image generating unit  15  corrects distortion of an omnidirectional image based on the correction parameters inputted from the image correcting sequencer  13 , and generates a distortion corrected image. The omnidirectional image acquiring unit  16  acquires an omnidirectional image captured by an imaging device (camera) using a fish-eye lens. This imaging device has a field of view including 360 degrees of a horizontal angle of view and 180 degrees of a vertical angle of view. The omnidirectional image is a circular or donut-shaped image, and distortion becomes more significant apart from the center. The imaging device is provided at a high place to an image capturing target place to shoot images downward. The omnidirectional image acquiring unit  16  acquires an omnidirectional image captured by the imaging device in a compressed image file format. The omnidirectional image acquiring unit  16  receives an image file of the omnidirectional image by way of, for example, wireless communication. 
     The omnidirectional image decoding unit  17  decodes the image file of the omnidirectional image acquired by the omnidirectional image acquiring unit  16 , and expands the omnidirectional image. The image queue  18  temporarily stores the omnidirectional image expanded by the omnidirectional image decoding unit  17 , and outputs the omnidirectional image to the image correcting sequencer  13  or the image display unit  19  where necessary. Using a monitor, the image display unit  19  displays the intermediate image generated by the intermediate image generating unit  14 , the distortion corrected image generated by the distortion corrected image generating unit  15  and the omnidirectional image expanded by the omnidirectional image decoding unit  17 . The image display unit  19  corresponds to a display unit according to the present invention. 
       FIG. 2  is a block diagram illustrating a detail configuration of the image correcting sequencer. As illustrated in  FIG. 2 , the image correcting sequencer  13  has a panel operation interface unit  131 , a timer control unit  132 , a target image deciding unit  133 , a display image deciding unit  134 , a correction parameter calculating unit  135  and an image correction interface unit  136 . 
     When a panel operation is changed, the panel operation interface unit  131  acquires content of this change from the operation detecting unit  12 . The timer control unit  132  controls a timer for a display switching period until a final target image is displayed. When display of an omnidirectional image is switched to display of a distortion corrected image, the distortion corrected image becomes a target image, and, when display of the distortion corrected image is switched to display of the omnidirectional image, the omnidirectional image becomes a target image. When the panel is operated, the timer control unit  132  sets a time out value according to specific content (an operation position and intensity) of this operation (tapping, dragging, flicking, pinching out, pinching in and rotation). Until time out occurs, an intermediate image is displayed and, after time out occurs, the target image is displayed. 
     The target image deciding unit  133  decides the target image based on content of a current panel operation. That is, when receiving an input of an operation of switching to display of a distortion corrected image while an omnidirectional image is displayed, the target image deciding unit  133  sets the distortion corrected image as a target image. In this case, the distortion corrected image includes a panoramic image and a clipped image, and therefore the target image deciding unit  133  also decides whether the target image is a panoramic image or a clipped image. Further, when receiving an input of an operation of switching to display of an omnidirectional image while a distortion corrected image is displayed, the target image deciding unit  133  sets the omnidirectional image as the target image. 
     The display image deciding unit  134  determines an image (an omnidirectional image, a distortion corrected image or an intermediate image) to be currently displayed according to timer control performed by the timer control unit  132 . When the image to be displayed is an intermediate image, the correction parameter calculating unit  135  determines correction parameters of an intermediate image to be displayed next according to a history of operation inputs, content of a current operation input and a timer value. The correction parameters include parameters related to a center coordinate, rotation and distortion. The image correction interface unit  136  invokes image generation processing per display image determined by the display image deciding unit  134 . 
     Switching of display performed using the viewer terminal  1  configured as described above will be described. Switching of display includes: (1) switching from omnidirectional image to panoramic image; (2) switching from panoramic image to omnidirectional image; (3) switching from omnidirectional image to multi image including clipped image; (4) switching from single panoramic image to double panoramic image; (5) switching from double panoramic image to single panoramic image; (6) scroll of panoramic image; (7) change of clipping range of clipped image; and (8) rotation of omnidirectional image. These will be described in order. 
     (1) Switching from Omnidirectional Image to Panoramic Image 
       FIG. 3  is a view explaining switching from display of an omnidirectional image to display of a panoramic image. In addition, although, in the present embodiment, the display unit of the viewer terminal  1  has a rectangular shape displays an omnidirectional image which is originally circular with upper and lower portions cut, an image to be displayed in this way is also referred to as an “omnidirectional image”. When an omnidirectional image is displayed as illustrated in  FIG. 3( a ) , a user first selects a base line (expansion line) to expand the omnidirectional image to a panoramic image. To select the base line, the user drags the omnidirectional image from a center of the omnidirectional image in a circumferential direction as illustrated in  FIG. 3( b ) . Next, as illustrated in  FIG. 3( c ) , the user pinches out the image crossing a dragging line. 
     The operation detecting unit  12  detects a type (dragging and pinching out), the speed and the position of this operation to output to the image correcting sequencer  13 . The operation panel interface unit  131  of the image correcting sequencer  13  receives an input of content and the position of this operation, and outputs the content and the position to the timer control unit  132  and the target image deciding unit  133 . 
     Based on a currently displayed image (omnidirectional image) and the content and the position of the operation, the target image deciding unit  133  decides that this operation is directed to changing the omnidirectional image to a panoramic image, decides that the target image is a panoramic image and outputs the result to the display image deciding unit  134  and the timer control unit  132 . The timer control unit  132  determines a time spent for a transition from the omnidirectional image to the panoramic image based on the speed at which two fingertips are separated upon pinching out, and starts a timer (that is, makes a transition time shorter when the speed at which fingertips are separated is faster). 
     When the timer value from the timer control unit  132  does not reach a time out value, the display image deciding unit  134  notifies to the image correction interface unit  136  that an image which needs to be displayed is an intermediate image to display the intermediate image according to the timer value, and outputs a time out value and a current timer value or a ratio of the current timer value with respect to the time out value to the correction parameter calculating unit  135 . 
     The correction parameter calculating unit  135  generates correction parameters to generate the intermediate image according to the ratio of the current timer value with respect to the time out value, and outputs the correction parameters to the image correction interface unit  136 . When the timer value reaches the time out value, the display image deciding unit  134  notifies to the image correction interface unit  136  that the image which needs to be displayed is a target image (that is, a panoramic image). 
     When notified by the display image deciding unit  134  that the image which needs to be displayed is the intermediate image, the image correction interface unit  136  invokes intermediate image generation processing of the intermediate image generating unit  14 , and outputs the correction parameters calculated by the correction parameter calculating unit  135  to the intermediate image generating unit  14 . The intermediate image generating unit  14  corrects the omnidirectional image using the correction parameters inputted from the correction parameter calculating unit  135 , generates an intermediate image and outputs the intermediate image to the image display unit  19 . 
     The timer control unit  132  outputs the timer value to the display image deciding unit  134  at a predetermined intermediate image frame rate, and the display image deciding unit  134  decides whether or not a timer value reaches a time out value in each case, notifies to the image correction interface unit  136  that the image which needs to be displayed is an intermediate image until the timer value reaches the time out value, and outputs the time out value and a current timer value, or a ratio of the current timer value with respect to the time out value to the correction parameter calculating unit  135 . Further, the correction parameter calculating unit  135  calculates correction parameters for generating an intermediate image, and the intermediate image generating unit  14  generates an intermediate image using the correction parameters. By this means, until time out occurs, the intermediate image is generated at the above intermediate image frame rate. 
       FIGS. 3( d ) and 3( e )  illustrate the intermediate image generated as described above. The intermediate image is an image which is in process of a transition from a circular omnidirectional image to a rectangular panoramic image, and shows a transition that an up and down direction is crushed downward, a left and right direction is stretched outward and a slit is made in the base line to gradually delete a lower half. 
     When the display image deciding unit  134  decides that a timer value times out as a result that the timer control unit  132  outputs a timer value at an intermediate image frame rate, the image correction interface unit  136  notifies to the distortion corrected image generating unit  15  that an image which needs to be displayed is a target image (that is, a distortion corrected image) from the display image deciding unit  134 . When receiving this notification, the distortion corrected image generating unit  15  corrects the omnidirectional image, and generates a panoramic image without distortion as illustrated in  FIG. 3( f ) . 
     In addition, all directions of 360 degrees of the horizontal angle of view of the panoramic image may be displayed on the image display unit  19 , and only part corresponding to a partial range of 360 degrees of the horizontal angle of view may be displayed. In the latter case, the panoramic image may be scrolled leftward and rightward by a scrolling operation. 
     In addition, although panoramic expansion is performed by drawing the base line from the center of the omnidirectional image in a vertical downward direction in the above example, panoramic expansion is not limited to this, and the base line may be drawn from the center of the omnidirectional image in an arbitrary circumferential direction. Also in this case, the intermediate image generating unit  14  and the distortion corrected image generating unit  15  expand the omnidirectional image such that the image is separated from this base line, and generates the intermediate image and the panoramic image. 
     (2) Switching from Panoramic Image to Omnidirectional Image 
       FIG. 4  is a view explaining switching from display of a panoramic image to display of an omnidirectional image. When a panoramic image is displayed as illustrated in  FIG. 4( a ) , the user pinches in the panoramic image in the left and right direction to change the panoramic image to an omnidirectional image. The operation detecting unit  12  detects a type (pinching in), the speed and the position of this operation to output to the image correcting sequencer  13 . The operation panel interface unit  131  of the image correcting sequencer  13  receives an input of content and the position of this operation, and outputs the content and the position to the timer control unit  132  and the target image deciding unit  133 . 
     Based on a currently displayed image (panoramic image) and the content and the position of the operation, the target image deciding unit  133  decides that this operation is directed to changing the panoramic image to the omnidirectional image, decides that the target image is the omnidirectional image and outputs the result to the display image deciding unit  134  and the timer control unit  132 . The timer control unit  132  determines a time spent for a transition from the panoramic image to the omnidirectional image based on the speed at which two fingertips come close upon pinch in, and starts a timer (that is, makes a transition time shorter when the speed at which fingertips come closer is faster). 
     The correction parameter calculating unit  135  generates correction parameters to generate the intermediate image according to the ratio of the current timer value with respect to the time out value, and outputs the correction parameters to the image correction interface unit  136 . When the timer value reaches the time out value, the display image deciding unit  134  notifies to the image correction interface unit  136  that the timer value reaches the time out value. 
     When notified by the display image deciding unit  134  that the image which needs to be displayed is the intermediate image, the image correction interface unit  136  invokes intermediate image generation processing of the intermediate image generating unit  14 , and outputs the correction parameters calculated by the correction parameter calculating unit  135  to the intermediate image generating unit  14 . The intermediate image generating unit  14  corrects the omnidirectional image using the correction parameters inputted from the correction parameter calculating unit  135 , generates an intermediate image and outputs the intermediate image to the image display unit  19 . 
     The timer control unit  132  outputs the timer value to the display image deciding unit  134  at a predetermined intermediate image frame rate, and the display image deciding unit  134  decides whether or not a timer value reaches a time out value in each case, notifies to the image correction interface unit  136  that the image which needs to be displayed is an intermediate image until the timer value reaches the time out value, and outputs the time out value and a current timer value, or a ratio of the current timer value with respect to the time out value to the correction parameter calculating unit  135 . Further, the correction parameter calculating unit  135  calculates correction parameters for generating an intermediate image, and the intermediate image generating unit  14  generates an intermediate image using the correction parameters. By this means, until time out occurs, the intermediate image is generated at the above intermediate image frame rate. 
       FIG. 4( b )  illustrates the intermediate image generated as described above. The intermediate image transitions such that the panoramic image is stretched in an upper direction and crushed inward in the left and right direction. 
     When the display image deciding unit  134  decides that a timer value times out as a result that the timer control unit  132  outputs a timer value at an intermediate image frame rate, the image correction interface unit  136  notifies to the image queue  18  that an image which needs to be displayed is a target image (that is, an omnidirectional image) from the display image deciding unit  134 . When receiving this notification, the image queue  18  outputs the omnidirectional image to the image display unit  19 , and the image display unit  19  displays the omnidirectional image as illustrated in  FIG. 4( c ) . In this case, a position pinched in on the panoramic image may correspond to a center on an entire periphery image which is a target image. 
       FIG. 5  is a flowchart of switching in case of above (1) and (2). The flow illustrated in  FIG. 5  is repeatedly executed per frame. The operation detecting unit  12  monitors whether or not the panel interface  11  is operated (step S 51 ), and, when the panel interface  11  is operated (YES in step S 51 ), the target image deciding unit  133  of the image correcting sequencer  13  decides whether the target image is a panoramic image or an omnidirectional image (step S 52 ). 
     Further, the timer control unit  132  updates a time out value (step S 53 ), and the correction parameter calculating unit  135  generates correction parameters (step S 54 ). Furthermore, the intermediate image generating unit  14  generates an intermediate image using the generated correction parameters. 
     Next, back to step S 51 , an operation of switching display has already been finished, and then it is decided that the panel interface  11  is not operated (NO in step S 51 ) and whether or not a timer value of the timer control unit times out is decided (step S 56 ). When the timer value does not time out (NO in step S 56 ), the correction parameter calculating unit  135  calculates correction parameters again using this timer value (step S 54 ) and the intermediate image generating unit  14  generates an intermediate image (step S 55 ). 
     When it is decided in step S 56  that the timer value times out by repeating the above processing (YES in step S 56 ), the display image deciding unit  134  decides whether or not the target image is the panoramic image according to the decision of the target image deciding unit  133  (step S 57 ). When the target image is the panoramic image (YES in step S 57 ), the distortion corrected image generating unit  15  generates a panoramic image by correcting distortion of the omnidirectional image (step S 58 ). When the target image is the omnidirectional image, the omnidirectional image is outputted as is without being corrected to the image display unit  19  from the image queue  18 , and is displayed on the image display unit  19  (step S 59 ). 
     (3) Switching from Omnidirectional Image to Multi Image Including Clipped Image 
       FIG. 6  is a view explaining switching from an omnidirectional image to a multi image including a clipped image. When an omnidirectional image is displayed as in  FIG. 6( a ) , areas which have differences from a previous frame equal to a threshold or more are detected in the omnidirectional image as moving objects in advance by a moving object detecting means which is not illustrated and, if the user wants to clip one of moving object areas and display a clipped image, the user needs to tap an area which needs to be clipped as illustrated in  FIG. 6( b ) . 
     The operation detecting unit  12  detects a type (tapping), the speed and the position of this operation to output to the image correcting sequencer  13 . The image correcting sequencer  13  clips the moving object area from the omnidirectional image, and the distortion corrected image generating unit  15  corrects distortion of this clipping area and generates a clipped image. As illustrated in  FIG. 6( c ) , the image display unit  19  superimposes the generated clipped image on the omnidirectional image to display. In this case, the clipped image is superimposed on the omnidirectional image based on a position as an initial position which overlaps the clipping area in the omnidirectional image. 
     As illustrated in  FIG. 6( c ) , the user can enlarge the clipped image by pinching out the clipped image which is superimposed on the omnidirectional image and displayed. Further, the user can reduce the clipped image by pinching in the clipped image which is superimposed on the omnidirectional image and displayed. 
     Furthermore, as illustrated in  FIG. 6( d ) , the user can also superimpose a plurality of clipped images on an omnidirectional image to display by generating clipped images of a plurality of areas. When the clipped image is superimposed on the omnidirectional image, if the user shakes the viewer terminal  1 , the superimposed and displayed clipped images aligned with the omnidirectional image and displayed to generate a multiscreen as illustrated in  FIG. 6( f ) . 
     (4) Switching from Single Panoramic Image to Double Panoramic Image 
       FIG. 7  is a view for explaining switching from a single panoramic image to a double panoramic image. When one panoramic image is displayed (single panoramic image), panoramic images of two upper and lower stages are displayed (double panoramic image) by pinching out this panoramic image as illustrated in  FIG. 7 . The upper and lower panoramic images of the double panoramic image may display panoramic images which do not overlap each other and show 180 degrees of the horizontal angle of view. 
     (5) Switching from Double Panoramic Image to Single Panoramic Image 
       FIG. 8  is a view explaining switching from a double panoramic image to a single panoramic image. As illustrated in  FIG. 8( a ) , when the double panoramic image is displayed, if the user wants to change this double panoramic image to a single panoramic image, the user touches the upper and lower panoramic images one by one by the fingers and pinches the images upward and downward such that the distance between these images becomes close. 
     As illustrated in  FIG. 8( b ) , the intermediate image correcting unit  15  generates an intermediate image in which the upper panoramic image moves downward and the lower panoramic image moves upward such that the two panoramic images overlap (the upper panoramic image becomes a top surface), and finally displays only the upper panoramic image as illustrated in  FIG. 8( c ) . 
     (6) Scrolling of Panoramic Image 
       FIG. 9  is a view explaining scrolling of a single panoramic image. When the panoramic image is displayed as illustrated in  FIG. 9( a ) , if the user wants to scroll this panoramic image in the horizontal direction, the user flicks the panoramic image in a direction in which the panoramic image needs to be scrolled. 
     In an example of  FIG. 9 ( a ) , the panoramic image is flicked in the right direction, and the panoramic image moves in the right direction as illustrated in  FIG. 9 ( b ) . In addition, after flicking, the panoramic image may be moved according to the quantity matching strength of flicking (a moving speed of a finger at which the finger is separated from the panel interface  11 ) and scrolling may be stopped and, when flicking is performed, scrolling may be continued at a certain speed. Further, a moving speed of a panoramic image may be determined according to the strength of flicking. 
       FIG. 10  is a view explaining scrolling of a double panoramic image. When the panoramic image is displayed as illustrated in  FIG. 10( a ) , if the user wants to scroll this double panoramic image in the horizontal direction, the user flicks one of upper and lower panoramic image of the double panoramic image in a direction in which the panoramic image needs to be scrolled. 
     In an example of  FIG. 10( a ) , the upper panoramic image is flicked in the right direction, and the upper panoramic image moves in the right direction as illustrated in  FIG. 10( b ) . In this case, the lower panoramic image is also moved rightward according to upward scrolling. In addition, similar to a single panoramic image, after flicking, upper and lower panoramic images may be moved according to the quantity matching the strength of flicking and, when flicking is performed, scrolling may be continued at a certain speed. Further, moving speeds of upper and lower panoramic images may be determined according to the strength of flicking. 
       FIG. 11  is a view explaining a modified example of scrolling of a panoramic image. A panoramic image can be scrolled by the above flicking and, in addition, by tilting the viewer terminal  1 . As illustrated in  FIG. 11( a ) , when the panoramic image is displayed, a panoramic image moves rightward as illustrated in  FIG. 11( b )  by tiling the viewer terminal  1  such that a right side of the viewer terminal  1  goes downward and the left side goes upward. Further, by tilting the viewer terminal  1  in a reverse direction, that is, by tilting the right side upward and the left side downward, the panoramic image moves leftward. In addition, also in this modified example, a moving speed of a panoramic image may be varied according to the degree of tilt. 
     In addition, a panoramic image can be scrolled by dragging. In this case, the panoramic image moves by the amount of dragging in a direction in which the panoramic image is dragged by dragging. 
     (7) Change of Clipping Range of Clipped Image 
       FIG. 12  is a view explaining change of a clipping range of a clipped image. When an omnidirectional image is displayed as illustrated in  FIG. 12( a ) , if the user wants to display a high quality image (of high resolution without distortion) of a partial area of this omnidirectional image, the user pinches out this area. In addition, only the area detected as a moving object by the moving object detecting means may be a pinching out target. 
     When pinching out is performed, the distortion corrected image generating unit  15  generates a clipped image of this area, and the image display unit  19  displays this clipped image in a full screen as illustrated in  FIG. 12( b ) . When a moving object moves in a clipped image, if the user wants to move an area for which a clipped image including this moving object is generated, the clipped image displayed in the full screen is dragged in a direction in which the image needs to be displayed as illustrated in  FIG. 12( c ) . The distortion corrected image generating unit  15  moves the clipping area in a dragging direction according to the amount of dragging and generates a new clipped image, and the image display unit  19  displays a clipped image continuously generated during dragging. 
     (8) Rotation of Omnidirectional Image 
       FIG. 13  is a view explaining rotation of an omnidirectional image. As illustrated in  FIG. 13( a ) , when an omnidirectional image is displayed, if this omnidirectional image needs to be rotated, as illustrated in  FIG. 13( b ) , two arbitrary points in the image are touched by the two fingers simultaneously and one or both of the two fingers are moved on the panel interface  11  such that a line connecting the two points rotates in the screen. 
     According to this rotation, the image display unit  19  changes a direction of the omnidirectional image to be displayed. In addition, when the two fingers perform flicking simultaneously, the omnidirectional image may continue rotating even after the fingers are separated from the panel interface  11 . 
     The above switching of display can be variously modified. Hereinafter, modified examples will be described. 
     First Modified Example 
       FIG. 14  is a view illustrating a first modified example. The first modified example is a modified example of switching from an omnidirectional image to a panoramic image. When the omnidirectional image is displayed as illustrated in  FIG. 14 , if the user wants to expand this omnidirectional image to the panoramic image, the user touches both left and right portions of the omnidirectional image by the fingers, and pinches out the omnidirectional image to widen outward. In addition, when a monitor is small, this pinching out can be performed by one hand (for example, the thumb and the forefinger), and, when a monitor is large, pinching out may be performed by the both hands as illustrated in  FIG. 14 . 
     According to the above pinching out, the omnidirectional image is continuously expanded to the panoramic image by being stretched outward. In this case, the omnidirectional image can be expanded to the panoramic image such that, for example, portions touched by the two fingers are connected by the line and a center coordinate is positioned on the line stretched from a midpoint in the vertical direction. 
     Also according to this first modified example, pinching out of both left and right ends of an omnidirectional image and switching of display that an omnidirectional image is stretched outward and transitions to a panoramic image sensuously match, so that operability and intelligibility for users improve. 
     Second Modified Example 
       FIG. 15  is a view illustrating a second modified example. The second modified example is a modified example of switching from an omnidirectional image to a panoramic image. When the omnidirectional image is displayed as illustrated in  FIG. 15 , if the user wants to expand this omnidirectional image to the panoramic image, the user touches both left and right portions of the omnidirectional image by the fingers, and pinches in the omnidirectional image to narrow inward. In addition, when a monitor is small, this pinching in can be performed by one hand (for example, the thumb and the forefinger), and, when a monitor is large, pinching in may be performed by the both hands as illustrated in  FIG. 15 . 
     According to the above pinching in, the omnidirectional image is continuously expanded to a panoramic image by being crashed inward. In this case, the omnidirectional image can be expanded to the panoramic image such that, for example, portions touched by the two fingers are connected by the line and a center coordinate is positioned on the line. 
     Also according to this second modified example, pinching in of both upper and lower ends of an omnidirectional image and switching of display that an omnidirectional image is crashed outward and transitions to a panoramic image sensuously match, so that operability and intelligibility for users improve. 
     Third Modified Example 
       FIG. 16  is a view illustrating a third modified example. The third modified example is a modified example of switching from an omnidirectional image to a panoramic image. When the omnidirectional image is displayed as illustrated in  FIG. 16( a ) , if the user wants to expand this omnidirectional image to the panoramic image, a center portion of the omnidirectional image is dragged by making a slit in the left and right direction as illustrated in  FIG. 16( a )  and then the omnidirectional image is pinched out upward and downward by the two fingers crossing the line provided as a slit as illustrated in  FIG. 16( b ) . 
     According to the above series of operations, the omnidirectional image is provided with a slit from a dragging line, and is continuously expanded to a panoramic image in a donut shape. In this case, the omnidirectional image can be expanded to the panoramic image such that, for example, a center coordinate is positioned on the line stretched from a midpoint of the dragging line in the vertical direction. 
     Also according to this third modified example, pinching out of an omnidirectional image by making a slit in the center portion of the omnidirectional image and switching of display that a slit is widened such that the omnidirectional image has a donut shape and transitions to a panoramic image sensuously match, so that operability and intelligibility for users improve. 
     In addition, although, in the above example, the center portion of the omnidirectional image is dragged in the horizontal direction to make a slit therein and the omnidirectional image is pinched out upward and downward by opening this slit, the present invention is not limited to this, and the center portion of the omnidirectional image may be dragged in the vertical direction to make a slit therein and the omnidirectional image is pinched out leftward and rightward by opening this slit or the omnidirectional image may be formed in a donut shape by widening the slit and transition to a panoramic image. 
     Fourth Modified Example 
       FIG. 17  is a view illustrating a fourth modified example. The fourth modified example is a modified example of switching from an omnidirectional image to a panoramic image. In this modified example, display of an omnidirectional image is switched to display of a double panoramic image. When an omnidirectional image is displayed as illustrated in  FIG. 17( a ) , if the user wants to expand this omnidirectional image to a double panoramic image, the user drags the omnidirectional image such that a slit is made in a diameter in the horizontal direction of the omnidirectional image as illustrated in  FIG. 17( a ) . Further, as illustrated in  FIG. 17( b ) , the omnidirectional image is pinched out upward and downward by the two fingers crossing the slit line. 
     According to the above series of operations, the omnidirectional image is expanded as upper and lower panoramic images at a boundary of a dragging line, and then a double panoramic image is displayed. In this case, the omnidirectional image can be expanded to the upper and lower panoramic images such that, for example, a center coordinate is positioned on the line stretched from a midpoint of the dragging line in the vertical direction. 
     Also according to this fourth modified example, pinching out of an omnidirectional image by making a slit in the center portion of the omnidirectional image and switching of display that an upper half and a lower half are expanded to an omnidirectional image to panoramic images at a boundary of a slit and are vertically arranged sensuously match, so that operability and intelligibility for users improve. 
     Fifth Modified Example 
       FIGS. 18 and 19  are views illustrating a fifth modified example. The fifth modified example is a modified example of switching from an omnidirectional image. In this modified example, a target image is switched according to a direction in which an omnidirectional image is pinched out. When pinching out is performed in a radial direction of the omnidirectional image as illustrated in  FIG. 18( a ) , a multi image including a clipped image is a target image as illustrated in  FIG. 18( b )  and the same operation as described in above “(3) switching from omnidirectional image to multi image including clipped image” is performed. In this case, a person at a pinched out position is enlarged and displayed as a clipped image. 
     Meanwhile, when pinching out is performed in a circumferential direction of the omnidirectional image as illustrated in  FIG. 19( a ) , a panoramic image is a target image as illustrated in  FIG. 19( b ) , and the same operation as switching to a panoramic image described in above “(1) switching from omnidirectional image to panoramic image” is performed. In this case, panoramic expansion is performed based on a line segment as a base line which connects a center of a line segment connecting finger positions which are pinched out and a center of the omnidirectional image. 
     Sixth Modified Example 
       FIGS. 20 and 21  are views illustrating a sixth modified example. The sixth modified example is a modified example of switching from a single panoramic image to a double panoramic image. In this modified example, an intermediate image is switched according to a direction in which the single panoramic image is pinched out. When a single panoramic image is pinched out in a vertical direction as illustrated in  FIG. 20( a ) , an intermediate image is generated and displayed similarly as described in “(4) switching from single panoramic image to double panoramic image” as illustrated in  FIG. 20 ( b ) , and a double panoramic image illustrated in  FIG. 20( c )  is displayed. 
     Meanwhile, when the single panoramic image is pinched out in the horizontal direction as illustrated in  FIG. 21( a ) , a panoramic image is cut at a vertical line segment which passes a center of a line segment connecting finger positions which are pinched out as illustrated in  FIG. 21( b ) , an intermediate image in which one of two cut panoramic images moves upward and the other one moves downward is generated and displayed as illustrated in  FIG. 21( c ) , and a double panoramic image illustrated in  FIG. 21( d )  is displayed. In addition, portions indicated by dotted lines in  FIGS. 21( b ) and 21( c )  are hidden portions which are not displayed in the intermediate image. These hidden portions are gradually displayed as the intermediate image develops. 
     As described above, the viewer terminal  1  according to the present embodiment can switch various types of display by a simple operation through an intuitive user interface using the panel interface  11 . Further, the viewer terminal  1  according to the present embodiment generates and displays an intermediate image during switching of display, so that the user can easily recognize a correlation before and after display is switched. 
     In addition, the operation of the above viewer terminal  1  may be realized by executing a computer program in a computation processing device provided in the viewer terminal  1 . 
     Although the preferred embodiment of the present invention which can be thought of at the present has been described above, the present embodiment can be variously deformed and the attached claims are intended to incorporate all such modifications within the spirit and the scope of the present invention. 
     INDUSTRIAL APPLICABILITY 
     As described above, the present invention is useful as, for example, a display device which allows display of an omnidirectional image and display of a distortion corrected image to be intuitively switched by a simple operation, and displays a video image captured by an omnidirectional camera. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  VIEWER TERMINAL 
               11  PANEL INTERFACE 
               12  OPERATION DETECTING UNIT 
               13  IMAGE CORRECTING SEQUENCER 
               14  INTERMEDIATE IMAGE GENERATING UNIT 
               15  DISTORTION CORRECTED IMAGE GENERATING UNIT 
               16  OMNIDIRECTIONAL IMAGE ACQUIRING UNIT 
               17  OMNIDIRECTIONAL IMAGE DECODING UNIT 
               18  IMAGE QUEUE 
               19  IMAGE DISPLAY UNIT 
               131  PANEL OPERATION INTERFACE UNIT 
               132  TIMER CONTROL UNIT 
               133  TARGET IMAGE DECIDING UNIT 
               134  DISPLAY IMAGE DECIDING UNIT 
               135  CORRECTION PARAMETER CALCULATING UNIT 
               136  IMAGE CORRECTION INTERFACE UNIT