Abstract:
Embodiments of the technology involve apparatus and methods for control of displaying of images. In an example, an apparatus may include an image display, a sensor to detect posture of the image display and a processor to control sequentially displaying images of a group of images on the image display based on changes in the detected posture. The processor may control a display of a posture indicator on the image display such that the indicator may represent a relation between a change in the detected posture and an image of the group of images. Optionally, the indicator may be represented by a tilt meter. Moreover, in some embodiments, the sensor may be implemented with a gyroscopic sensor.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an image processing device, and more particularly, to an image processing device and an image processing method for displaying an image, and a program for causing a computer to execute the method. 
       BACKGROUND ART 
       [0002]    In recent years, imaging devices such as a digital still camera or a digital video camera (e.g., a camera-integrated recorder) for imaging a subject such as a person or an animal to generate image data and recording the image data as image content have been used. 
         [0003]    For example, there is a reproduction apparatus for performing image advancing by user manipulation using a manipulation member and sequentially displaying a plurality of images. Also, there is a reproduction apparatus in which a user changes a posture of the reproduction apparatus to change displayed content of a display unit. 
         [0004]    For example, an information processing device for obtaining a movement amount or a rotation amount of a body and instructing, for example, to scroll displayed content of a display unit according to the amount has been proposed (e.g., see Patent Literature 1). 
       CITATION LIST 
     Patent Literature 
     PTL 1 
       [0000]    
       
         Japanese Patent Application Laid-Open No. H06-4208 (FIG. 3) 
       
     
       SUMMARY OF INVENTION 
       [0006]    Some embodiments of the present technology may involve a method of a processor to control a display of images. The method may involve detecting posture of an image display device with a sensor. The method may also involve sequentially displaying images of a group of images on the image display device based on changes in the detected posture. The method may also involve displaying a posture indicator on the image display device, the indicator representing a relation between a change in the detected posture and an image of the group of images. 
         [0007]    Optionally, the indicator may include a graphic tilt meter. In some embodiments, the processor may associate a normalized tilt angle with an image of the sequentially displayed images. The normalized tilt angle may comprise an angle determined as a function of image capture angle information and a maximum tilt angle. In some embodiments, the image capture angle information may comprise a range of captured image angles. Still further, the maximum tilt angle may comprise a display viewing angle limit. In some cases, the method may also involve sequentially displaying entrance images for groups of images on the image display device based on changes in the detected posture. Optionally, the sensor may comprise a gyroscopic sensor. 
         [0008]    Some embodiments of the present technology may involve an apparatus for control of displaying of images. The apparatus may include an image display, a sensor to detect posture of the image display and a processor to control sequentially displaying images of a group of images on the image display based on changes in the detected posture. The processor may control a display of a posture indicator on the image display such that the indicator may represent a relation between a change in the detected posture and an image of the group of images. 
         [0009]    Optionally, the indicator may comprise a tilt meter. Still further, the processor may control associating a normalized tilt angle with an image of the sequentially displayed images. The detection of posture may comprise a detection of angular velocity. Moreover, the processor may control changing the display based on the angular velocity. In some cases of the apparatus, the processor may control calculating the normalized tilt angle as a function of image capture angle information and a maximum tilt angle. The image capture angle information may comprise a range of captured image angles. The maximum tilt angle may comprise a display viewing angle limit. In some such embodiments, the processor may control sequentially displaying entrance images for groups of images on the image display device based on changes in the detected posture. The sensor may include a gyroscopic sensor. 
         [0010]    In still further embodiments of the technology may involve a system for control of displaying images. The system may include a display means for image displaying. The system may also include a posture means for sensing posture of the means for image displaying. The system may also include a control means for controlling sequentially displaying images of a group of images on the display means based on changes in the sensed posture. In some cases, the control means may control a display of a means for posture indicating on the image display, the means for posture indicating representing a relation between a change in the sensed posture and an image of the group of images. Still further, the control means may control associating of a normalized tilt angle with an image of the sequentially displayed images. Moreover, the control means may control calculating the normalized tilt angle as a function of image capture angle information and a maximum tilt angle. In some cases, such an image capture angle information may comprise a range of captured image angles determined by the posture means. 
       TECHNICAL PROBLEM 
       [0011]    According to the above-described related art, the displayed content of the display unit can be changed by changing the posture of a device, making it possible for a user to perform a changing manipulation in a state in which the user holds the device by hand. 
         [0012]    Here, a case in which image advancing or image returning is performed on a plurality of images by changing posture of a device is assumed. In this case, a user performs a manipulation to change posture of the device while viewing images sequentially displayed on the display unit. Accordingly, it is understood that the user can easily perform the manipulation if he or she can easily recognize an image advancing or image returning timing or a position relationship of display images in an image group while viewing images sequentially displayed on the display unit. 
         [0013]    In light of the foregoing, it is desirable to easily perform a manipulation to sequentially display a plurality of images using a manipulation method of changing posture of a device. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0014]      FIG. 1A  shows an appearance configuration example of an imaging device  100  in a first embodiment of the present invention. 
           [0015]      FIG. 1B  shows an appearance configuration example of an imaging device  100  in a first embodiment of the present invention. 
           [0016]      FIG. 2A  shows one example of posture when the imaging device  100  is used in the first embodiment of the present invention. 
           [0017]      FIG. 2B  shows one example of posture when the imaging device  100  is used in the first embodiment of the present invention. 
           [0018]      FIG. 2C  shows one example of posture when the imaging device  100  is used in the first embodiment of the present invention. 
           [0019]      FIG. 3  is a block diagram showing a functional configuration example of the imaging device  100  in the first embodiment of the present invention. 
           [0020]      FIG. 4  schematically shows stored content of the image management information storage unit  210  in the first embodiment of the present invention. 
           [0021]      FIG. 5A  shows a display example of a representative image displayed on an input/output panel  101  by a representative image reproduction unit  150  in the first embodiment of the present invention. 
           [0022]      FIG. 5B  shows a display example of a representative image displayed on an input/output panel  101  by a representative image reproduction unit  150  in the first embodiment of the present invention. 
           [0023]      FIG. 6  schematically shows an image display transition example in the input/output panel  101  in the first embodiment of the present invention. 
           [0024]      FIG. 7  schematically shows an image display transition example in the input/output panel  101  in the first embodiment of the present invention. 
           [0025]      FIG. 8A  shows one example of a position relationship between a subject and the imaging device  100  in an imaging operation performed using the imaging device  100 , and an imaged image group generated in the imaging operation in the first embodiment of the present invention. 
           [0026]      FIG. 8B  shows one example of a position relationship between a subject and the imaging device  100  in an imaging operation performed using the imaging device  100 , and an imaged image group generated in the imaging operation in the first embodiment of the present invention. 
           [0027]      FIG. 9A  shows one example of a change of posture of the imaging device  100  and angle information normalization performed by a manipulation method determination unit  180  in the first embodiment of the present invention. 
           [0028]      FIG. 9B  shows one example of a change of posture of the imaging device  100  and angle information normalization performed by a manipulation method determination unit  180  in the first embodiment of the present invention. 
           [0029]      FIG. 9C  shows one example of a change of posture of the imaging device  100  and angle information normalization performed by a manipulation method determination unit  180  in the first embodiment of the present invention. 
           [0030]      FIG. 10  shows one example of a method of associating an image to be displayed and a tilt angle range in the manipulation method determination unit  180 , and an image displayed after the association and manipulation support information in the first embodiment of the present invention. 
           [0031]      FIG. 11  schematically shows a method of calculating a display area of an indicator in the manipulation method determination unit  180  in the first embodiment of the present invention. 
           [0032]      FIG. 12  shows a display example of an indicator based on a display area of an indicator calculated by the manipulation method determination unit  180  in the first embodiment of the present invention. 
           [0033]      FIG. 13  schematically shows a method of determining the number of images to be displayed and a method of interleaving images to be displayed in the manipulation method determination unit  180  in the first embodiment of the present invention. 
           [0034]      FIG. 14  schematically shows a method of setting the display area of the indicator in the manipulation method determination unit  180  in the first embodiment of the present invention. 
           [0035]      FIG. 15  shows a display transition example of manipulation support information (tilt meter) displayed by the group image reproduction unit  160  in the first embodiment of the present invention. 
           [0036]      FIG. 16  shows a display transition example of manipulation support information (tilt meter) displayed by the group image reproduction unit  160  in the first embodiment of the present invention. 
           [0037]      FIG. 17A  shows a display transition example of manipulation support information (tilt meter) displayed by the group image reproduction unit  160  in the first embodiment of the present invention. 
           [0038]      FIG. 17B  shows a display transition example of manipulation support information (tilt meter) displayed by the group image reproduction unit  160  in the first embodiment of the present invention. 
           [0039]      FIG. 17C  shows a display transition example of manipulation support information (tilt meter) displayed by the group image reproduction unit  160  in the first embodiment of the present invention. 
           [0040]      FIG. 18  schematically shows a relationship between a display transition in the input/output panel  101  and the posture of the imaging device  100  in the first embodiment of the present invention. 
           [0041]      FIG. 19  schematically shows a relationship between a display transition in the input/output panel  101  and the posture of the imaging device  100  in the first embodiment of the present invention. 
           [0042]      FIG. 20  is a flowchart showing an example of a processing procedure in an image content reproduction process in the imaging device  100  in the first embodiment of the present invention. 
           [0043]      FIG. 21  is a flowchart showing an example of a processing procedure in an image content reproduction process in the imaging device  100  in the first embodiment of the present invention. 
           [0044]      FIG. 22  is a flowchart showing an example of a group image display mode setting process in a processing procedure of an image content reproduction process in the imaging device  100  in the first embodiment of the present invention. 
           [0045]      FIG. 23A  shows manipulation support information (tilt meter) displayed by a group image reproduction unit  160 . 
           [0046]      FIG. 23B  shows a display transition example in the input/output panel  101  in a variant of the first embodiment of the present invention. 
           [0047]      FIG. 24A  shows manipulation support information (tilt meter) displayed by a group image reproduction unit  160 . 
           [0048]      FIG. 24B  shows a display transition example in the input/output panel  101  in a variant of the first embodiment of the present invention. 
           [0049]      FIG. 25  shows a display transition example in the input/output panel  101  in a variant of the first embodiment of the present invention. 
           [0050]      FIG. 26  shows a display transition example in the input/output panel  101  in a variant of the first embodiment of the present invention. 
           [0051]      FIG. 27  shows a display transition example in the input/output panel  101  in a variant of the first embodiment of the present invention. 
           [0052]      FIG. 28  shows a display transition example in the input/output panel  101  in a variant of the first embodiment of the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0053]    Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the appended drawings. Note that, in this specification and the appended drawings, structural elements that have substantially the same function and structure are denoted with the same reference numerals, and repeated explanation of these structural elements is omitted. 
         [0054]    The description will be given in the following order. 
         [0000]    1. First embodiment (display control: an example in which an indicator or a tilt meter superimposed on an image in a group is displayed in a group image display mode) 
       2. Variant 
     1. First Embodiment 
     Appearance Configuration Example of Imaging Device 
       [0055]      FIGS. 1A and 1B  show an appearance configuration example of an imaging device  100  in a first embodiment of the present invention.  FIG. 1A  is a perspective view showing an appearance at a display surface side of the imaging device  100 .  FIG. 1B  is a side view showing an appearance at the display surface side of the imaging device  100 . The imaging device  100  is realized, for example, by a digital still camera or a digital video camera (e.g., camera-integrated recorder) capable of imaging a subject to generate image data, recording the image data as image content, and displaying the image content. 
         [0056]    The imaging device  100  includes an input/output panel  101  and a shutter button  102 . The imaging device  100  is an image processing device that can be carried by a user and the user can view an image displayed on the input/output panel  101 . The imaging device  100  is one example of an image processing device defined in the claims. 
         [0057]    The input/output panel  101  displays various images and receives a manipulation input from a user by detecting a contact manipulation on the input/output panel  101 . The shutter button  102  is a button pressed by a photographer when image data (an imaged image) generated by imaging a subject is recorded as image content (a still image file). 
         [0058]    The imaging device  100  includes other manipulation members such as a power switch and a mode switching switch, a lens unit, and the like, but such manipulation members will not be shown and described herein for ease of explanation. Here, the lens unit (not shown) is an optical system including a plurality of lenses for focusing light from the subject, an aperture, and the like. 
         [0059]    Here, a change of posture of the imaging device  100  will be described. For example, the user may change rotation angles (i.e., a yaw angle, a pitch angle, and a roll angle) about three orthogonal axes in a state in which the user holds the imaging device  100  by hand. For example, the user may change the posture of the imaging device  100  in a direction indicated by the arrow  302  (the yaw angle), the axis of which is the arrow  300  (or the arrow  301 ). The change example is shown in  FIG. 2B . For another example, the user may change the posture of the imaging device  100  in a direction indicated by the arrow  305  (the pitch angle), the axis of which is the arrow  303  (or the arrow  304 ). For yet another example, the user may change the posture of the imaging device  100  in a direction indicated by the arrow  308  (the roll angle), the axis of which is the arrow  306  (or the arrow  307 ). 
         [0060]    Further, for example, the user may change the posture of the imaging device  100  by moving (sliding) the imaging device  100  along a straight line on a plane in a state in which the user holds the imaging device  100  by hand. For example, the user may change the posture by moving the imaging device  100  in the direction indicated by the arrow  300  or the arrow  301  (movement in a vertical direction in  FIG. 1B ). For another example, the user may change the posture by moving the imaging device  100  in a direction indicated by the arrow  303  or  304  (movement in a horizontal direction in  FIG. 1B ). This change example is shown in  FIG. 2C . Further, for example, the user may change the posture by moving the imaging device  100  in a direction indicated by the arrow  306  or  307 . 
       Use Example of Imaging Device 
       [0061]      FIGS. 2A to 2C  show one example of the posture when the imaging device  100  is used in the first embodiment of the present invention. In  FIG. 2A , one example of the posture of the imaging device  100  when image content reproduction is performed using the imaging device  100  is shown. When a person  310  performs the image content reproduction using the imaging device  100 , the person  310  may view an image displayed on the input/output panel  101 , for example, in a state in which the person  310  holds the imaging device  100  with both hands as shown in  FIG. 2A . 
         [0062]    In  FIGS. 2B and 2C , a transition example in which the posture of the imaging device  100  is changed is shown. In  FIG. 2B , a transition example when the imaging device  100  is rotated in the direction indicated by the arrow  302  about the arrow  300  ( 301 ) shown in  FIG. 1A  to change the posture is shown. 
         [0063]    In  FIG. 2C , a transition example in which the imaging device  100  is moved in the direction indicated by the arrows  303  and  304  shown in  FIGS. 1A and 1B  to change the posture is shown. In the first embodiment of the present invention, an example in which an image displayed on the input/output panel  101  is sequentially changed by changing the posture of the imaging device  100  as such is shown. That is, an example in which the image displayed on the input/output panel  101  is sequentially changed by gesture manipulation by the user is shown. Such changes of the image display status will be described in detail with reference to  FIGS. 6 ,  7 , or the like. 
       Functional Configuration Example of Imaging Device 
       [0064]      FIG. 3  is a block diagram showing a functional configuration example of the imaging device  100  in the first embodiment of the present invention. The imaging device  100  includes an input/output unit  110 , a posture detection unit  120 , an analysis unit  130 , a control unit  140 , a representative image reproduction unit  150 , a group image reproduction unit  160 , a rendering memory  170 , and the manipulation method determination unit  180 . Moreover, the imaging device  100  includes an image content storage unit  200 , and an image management information storage unit  210 . 
         [0065]    The image content storage unit  200  stores image data (an imaged image) generated by the imaging unit (not shown) as an image file (image content (still image content or moving image content)). The image content storage unit  200  supplies the stored image content to the representative image reproduction unit  150  or the group image reproduction unit  160 . In the first embodiment of the present invention, an example in which the still image content is used as the image content is shown. 
         [0066]    The image management information storage unit  210  stores management information (image management information) on the image content stored in the image content storage unit  200 . Using the image management information, reproduction in the representative image display mode and the group image display mode is performed. Here, the representative image display mode is a mode in which a representative image of grouped image contents and an image of non-grouped image content among the image contents stored in the image content storage unit  200  are sequentially displayed according to user manipulation. The group image display mode is a mode in which images of each grouped image content among the image contents stored in the image content storage unit  200  are sequentially displayed according to the change of the posture of the imaging device  100 . The image content storage unit  200  and the image management information storage unit  210  may be, for example, one or a plurality of removable recording media, such as discs, such as digital versatile discs (DVDs) or semiconductor memories such as memory cards. The recording media may be embedded in the imaging device  100  or detachably provided in the imaging device  100 . 
         [0067]    The input/output unit  110  includes a display unit  111  and a manipulation receiving unit  112 . The display unit  111  is a display unit for displaying an image supplied from the representative image reproduction unit  150  or the group image reproduction unit  160 . Various menu screens or various images are displayed on the display unit  111 . The display unit  111  may be, for example, a liquid crystal display (LCD) or an organic electro luminescence (EL) panel. 
         [0068]    The manipulation receiving unit  112  is a manipulation receiving unit for receiving content of a manipulation by the user, and supplies a manipulation signal dependent on the received manipulation content to the control unit  140 . The manipulation receiving unit  112  corresponds to, for example, the manipulation member such as the shutter button  102  shown in  FIGS. 1A and 1B  or a touch panel. For example, the touch panel is superimposed on the display unit  111  to transmit the screen of the display unit  111 , and receives a manipulation input from the user by detecting an object contacting the display surface. That is, when a user presses a desired location, for example, by touching the display surface in the input/output unit  110  with his or her finger, the touch panel detects a coordinate of the pressed location and outputs a manipulation signal corresponding to the detected coordinate to the control unit  140 . When the control unit  140  acquires the manipulation signal, the control unit  140  executes a predetermined process based on the acquired manipulation signal. The manipulation receiving unit  112  may be, for example, a touch panel for converting a contact on a display surface into an electrical signal using a dedicated sensing device and outputting the converted electrical signal to the control unit  140 . Further, the manipulation receiving unit  112  may be, for example, a touch panel of an optical sensor type capable of detecting an object (e.g., a user&#39;s finger) approaching or contacting a display surface. The input/output unit  110  corresponds to a manipulation member such as the shutter button  102  or the input/output panel  101  shown in  FIGS. 1A and 1B . 
         [0069]    The posture detection unit  120  detects a change of the posture of the imaging device  100  by detecting acceleration, movement, tilt and the like of the imaging device  100 , and outputs posture change information about the detected change of the posture to the analysis unit  130 . For example, the posture detection unit  120  detects a movement direction and a movement amount in a specific direction of the imaging device  100 , and an angular velocity in the specific direction (an angular velocity when the posture of the imaging device  100  is changed) as the change of the posture of the imaging device  100 . The posture detection unit  120  may be realized by a gyro sensor (angular velocity sensor) or an acceleration sensor. The posture detection unit  120  is an example of a detection unit defined in the claims. 
         [0070]    The analysis unit  130  analyzes the change amount (e.g., the movement direction and the movement amount) of the posture of the imaging device  100  based on the posture change information output from the posture detection unit  120  to generate analysis information for performing display switching on the image or the manipulation support information displayed on the display unit  111 . The analysis unit  130  outputs the analysis information to the group image reproduction unit  160 . 
         [0071]    The control unit  140  controls each unit of the imaging device  100  based on the manipulation content from the manipulation receiving unit  112 . For example, the control unit  140  sets the representative image display mode when the manipulation receiving unit  112  receives a representative image display mode setting manipulation and sets the group image display mode when the manipulation receiving unit  112  receives a group image display mode setting manipulation. 
         [0072]    Further, when the group image display mode setting manipulation is received, the control unit  140  performs a control to sequentially display, on the display unit  111 , the images in the group corresponding to the representative image displayed on the display unit  111  upon the setting manipulation. When the group image display mode is set, the control unit  140  performs a control to display, on the display unit  111 , the manipulation support information indicating a relationship between the change of the posture of the imaging device  100  and the display state in the display unit  111 . The manipulation support information is information for supporting a manipulation to change the display state in the display unit  111  and is, for example, an indicator  660  shown in  FIG. 18(   a ) or a tilt meter  670  shown in  FIG. 19(   a ). Further, the control unit  140  performs a control to display, on the display unit  111 , the manipulation support information based on the position of the posture of the imaging device  100  associated by the manipulation method determination unit  180  and the plurality of image contents. 
         [0073]    When the representative image display mode has been set and an instruction manipulation to instruct display switching (e.g., image advancing and image returning) of the image displayed on the display unit  111  is received, the control unit  140  instructs the representative image reproduction unit  150  to switch the image display based on the instruction manipulation. Further, when a group image display mode setting manipulation is performed, the control unit  140  acquires the image management information (the manipulation method  215 , or the like, shown in  FIG. 4 ) associated with the group corresponding to the representative image displayed on the display unit  111  upon a setting manipulation from the group image reproduction unit  160 . The control unit  140  is realized by, for example, a central processing unit (CPU). 
         [0074]    The representative image reproduction unit  150  displays, on the display unit  111 , image content corresponding to the representative image and non-grouped image content among the image contents stored in the image content storage unit  200  under control of the control unit  140 . Specifically, when the representative image display mode has been set, the representative image reproduction unit  150  acquires the image content corresponding to the representative image and non-grouped image content from the image content storage unit  200 . Subsequently, the representative image reproduction unit  150  decodes the acquired image content and renders a display image in the rendering memory  170  based on the decoded image content. The representative image reproduction unit  150  sequentially displays one of the images rendered in the rendering memory  170  on the display unit  111  under control of the control unit  140 . The representative image reproduction unit  150  displays, on the display unit  111 , the representative image, and manipulation support information (e.g., the manipulation support information  261  shown in  FIG. 5 ) supporting the setting manipulation to the group image display mode for displaying each image in the group corresponding to the representative image. Further, the representative image reproduction unit  150  displays, on the display unit  111 , the representative image, and manipulation support information (e.g., the manipulation support information  251 ,  252 ,  256 , and  257  shown in  FIG. 5 ) indicating the representative image, and a type of the group corresponding to the representative image (e.g., the group type  216  shown in  FIG. 4 ). 
         [0075]    The group image reproduction unit  160  displays the grouped image contents among the image contents stored in the image content storage unit  200  on the display unit  111  in a group unit under control of the control unit  140 . Specifically, when the group image display mode is set, the group image reproduction unit  160  acquires each image content belonging to the group corresponding to the representative image displayed upon the group image display mode setting manipulation from the image content storage unit  200 . Further, the group image reproduction unit  160  acquires the image management information associated with each image content belonging to the group from the image management information storage unit  210 . Subsequently, the group image reproduction unit  160  outputs the acquired image management information to the manipulation method determination unit  180 . Moreover, for example, the group image reproduction unit  160  decodes the acquired image content and renders a display image in the rendering memory  170  based on the decoded image content. In this case, the group image reproduction unit  160  arranges display images and renders the images in the rendering memory  170 , for example, according to a predetermined rule. 
         [0076]    When the group image display mode setting manipulation is received, the group image reproduction unit  160  displays each image belonging to a group to be displayed and manipulation support information on the display unit  111  to be associated with each other. In this case, for example, the group image reproduction unit  160  changes content of the manipulation support information based on the change of the posture of the imaging device  100  detected by the posture detection unit  120 . That is, the group image reproduction unit  160  sequentially displays, on the display unit  111 , one image from among the images rendered in the rendering memory  170  based on the image display switching instruction output from the analysis unit  130  (an image advancing or returning instruction). 
         [0077]    The rendering memory  170  is a rendering buffer for holding the images rendered by the representative image reproduction unit  150  or the group image reproduction unit  160 , and supplies the rendered images to the representative image reproduction unit  150  or the group image reproduction unit  160 . 
         [0078]    The manipulation method determination unit  180  determines the manipulation method when grouped image content is in a group unit displayed on the display unit  111 , based on the image management information output from the group image reproduction unit  160 . For example, the manipulation method determination unit  180  normalizes the angle information assigned to a plurality of image contents, for each image content, using a range in which the posture of the imaging device  100  is changed, as a reference. The manipulation method determination unit  180  determines the manipulation method by associating the position of the posture of the imaging device  100  with the plurality of image contents, for each image content, based on the normalized angle information, and outputs the determined manipulation method to the group image reproduction unit  160 . A method of determining the manipulation method will be described in detail with reference to  FIGS. 8A to 14 . 
       (Stored Content of Image Management Information Storage Unit) 
       [0079]      FIG. 4  schematically shows stored content of the image management information storage unit  210  in the first embodiment of the present invention. Group identification information  211 , image content identification information  212 , group presence  213 , a representative image  214 , a manipulation method  215 , and a group type  216  are stored in the image management information storage unit  210 . 
         [0080]    Identification information for identifying each group is stored in the group identification information  211 . Here, the group is an image group including a plurality of image contents associated with one another, the order of which is specified based on a predetermined rule. In the first embodiment of the present invention, an example in which an image group including a plurality of image contents, and image contents not in the image group are assigned group identification information to identify the image contents not in the image group and the image group is shown. 
         [0081]    Identification information (image content identification information) for identifying each image content stored in the image content storage unit  200  is stored in the image content identification information  212 . For example, the image content identification information of each image content is stored in an image advancing or returning order (e.g., an order of photographing time (record date)). 
         [0082]    Angle information corresponding to an imaging operation when the image content stored in the image content storage unit  200  is generated is stored in the angle information  213 . For example, when a multi-view image is photographed using the imaging device  100  and the multi-view image generated by the photograph is stored in the image content storage unit  200 , an angle upon photographing (an angle when a predetermined position is used as a reference) is stored as the angle information. “Absence” is shown in the field of the image content not assigned the angle information. Here, the multi-view image is a plurality of images generated by an imaging operation changing a view with respect to a target subject (e.g., a face of a person) by moving the imaging device  100  using the target subject as a reference. The imaging operation will be described in detail with reference to  FIG. 8A . 
         [0083]    Representative image information for specifying a representative image among a plurality of grouped image contents is stored in the representative image  214 . In the example shown in  FIG. 4 , image content identification information (image content identification number) of image content corresponding to the representative image is shown as the representative image information. Further, “absence” is indicated in the field of the non-grouped image content. That is, it is possible to identify whether the image contents are grouped (whether the image contents belong to a group) based on whether the image content identification information is stored in the representative image  214 . 
         [0084]    A manipulation method when a plurality of grouped image contents are sequentially displayed in the case in which the group image display mode has been set is stored in the manipulation method  215 . The manipulation method is a manipulation method relating to the change of the posture of the imaging device  100 . For example, “horizontal rotation” refers to a manipulation to sequentially display a plurality of image contents by rotating the imaging device  100  in the direction indicated by the arrow  302  about the arrow  300  ( 301 ) shown in  FIGS. 1A and 1B  to change the posture. Further, for example, “vertical rotation” refers to a manipulation to sequentially display a plurality of image contents by rotating the imaging device  100  in the direction indicated by the arrow  305  about the arrow  303  ( 304 ) shown in  FIGS. 1A and 1B  to change the posture. Further, for example, “horizontal movement” refers to a manipulation to sequentially display a plurality of image contents by moving the imaging device  100  in the direction indicated by the arrows  303  and  304  shown in  FIGS. 1A and 1B  to change the posture. For example, a “vertical movement” refers to a manipulation to sequentially display a plurality of image contents by moving the imaging device  100  in the direction indicated by the arrows  300  and  301  shown in  FIGS. 1A and 1B  to change the posture. The imaging device  100  can automatically determine the manipulation method, for example, according to an imaging operation method upon generating the image contents. Further, the manipulation method may be appropriately determined according to the user&#39;s preference by the user manipulation. 
         [0085]    The type relating to a group (image group) including a plurality of image contents the order of which is specified based on a predetermined rule and that are associated with each other is stored in the group type  216 . In  FIG. 4 , an example in which “multi-shot image” and “multi-view image” are stored as the group type is shown. Here, “multi-shot image” is the type of a group including a plurality of images generated by multi-shot photographing and “multi-view image” is the type of a group including a plurality of images generated by multi-view photographing. “Absence” is indicated in the field of the non-grouped image content. Further, when the representative image display mode has been set, the representative image and the type of a group corresponding to the representative image based on content of the group type  216  can be displayed. This display example is shown in  FIG. 5 . 
         [0086]    The information stored in the group identification information  211 , the group presence  213 , the representative image  214 , the manipulation method  215  and the group type  216  may be recorded in an image file (image content). For example, such information can be recorded as attribute information relating to a still image file. The information recorded in the image content may be used upon reproduction of the image content. 
       Display Example of Representative Image 
       [0087]      FIGS. 5A and 5B  shows a display example of the representative image displayed on the input/output panel  101  by the representative image reproduction unit  150  in the first embodiment of the present invention. In  FIG. 5A , a display example when a representative image of a group in which “multi-view image” is stored in the group type  216  is displayed is shown. Further, in  FIG. 5B , a display example in which a representative image of a group in which “multi-shot image” is stored in the group type  216  is displayed is shown. 
         [0088]    As shown in  FIG. 5A , when the representative image  250  of the group relating to the multi-view image is displayed on the input/output panel  101 , manipulation support information (decoration image)  251  and  252  indicating that the group is a group relating to the multi-view image is displayed at both sides of the representative image  250 . Further, a group type display area  262  and an image size display area  263  are provided on the representative image  250 , and manipulation support information  261  for setting the group image display mode is provided below the representative image  250 . 
         [0089]    In the group type display area  262 , the type of the group corresponding to the displayed representative image is displayed. For example, when the type of the group corresponding to the displayed representative image is a group relating to the multi-view image, “multi-view” is displayed in the group type display area  262 . 
         [0090]    In the image size display area  263 , an image size of each image belonging to the group corresponding to the displayed representative image (e.g., an image size of one image) is displayed. 
         [0091]    The manipulation support information  261  is a manipulation button for supporting a manipulation to set the group image display mode upon setting of the representative image display mode. That is, the user can set the group image display mode by pressing the manipulation support information  261 . Further, the same letters as the group type in the group type display area  262  is displayed in a rectangle corresponding to the manipulation support information  261 . 
         [0092]    Further, as shown in  FIG. 5B , when a representative image  255  of a group relating to a multi-shot image is displayed on the input/output panel  101 , manipulation support information (decoration image)  256  and  257  indicating that the group is the group relating to the multi-shot image is displayed at both sides of the representative image  255 . Further, a group type display area  262  and an image size display area  263  are provided on the representative image  255 , and manipulation support information  261  for setting the group image display mode is provided below the representative image  255 . 
         [0093]    Thus, when the representative image display mode has been set, a display aspect of the representative image is changed for each image group based on correlativity (e.g., corresponding to group type) between images in the image group associated with the representative image displayed on the input/output panel  101 , and then the representative image is displayed. 
         [0094]    As shown in  FIG. 5B , when the type of the group corresponding to the displayed representative image is the group relating to the multi-shot image, “multi-shot” is displayed in the group type display area  262 . Further, “multi-shot” is displayed in a rectangle corresponding to the manipulation support information  261 . 
       Image Display Transition Example 
       [0095]      FIGS. 6 and 7  schematically show image display transition examples on the input/output panel  101  in the first embodiment of the present invention. In  FIG. 6(   a ), a case in which the image contents stored in the image content storage unit  200  are arranged according to a predetermined rule (order of image content identification information) is schematically shown. In the example shown in  FIG. 6(   a ), only image contents # 1  to # 13  among the image contents stored in the image content storage unit  200  are shown. Further, the image contents # 1  to # 13  correspond to # 1  to # 13  indicated in the image content identification information  212  of  FIG. 4 . In  FIG. 6 , image contents and corresponding images are schematically shown by rectangles with image content identification information (# 1  to # 13 ). Further, grouped image contents are surrounded in a group unit by dotted rectangles. 
         [0096]    In  FIG. 6(   b ), a transition of images displayed on the input/output panel  101  when the representative image display mode has been set is shown. As shown in  FIG. 6(   b ), non-grouped image contents (# 1 , # 5 , # 6 , and # 13 ) and representative images (# 3  and # 9 ) of the grouped image contents are sequentially displayed based on an image advancing manipulation or an image returning manipulation by the user. The image advancing manipulation or the image returning manipulation is performed, for example, using the manipulation member included in the imaging device  100  (e.g., the touch panel or an external manipulation button (not shown)). Further, the image advancing manipulation or the image returning manipulation may be performed, for example, according to the change of the posture of the imaging device  100 , similar to setting of the group image display mode. 
         [0097]    In  FIG. 7(   a ), a display transition example in which image contents # 6 , # 9  and # 13  among the images shown in  FIG. 6(   b ) are sequentially displayed based on the image advancing manipulation or the image returning manipulation by the user is shown. 
         [0098]    In  FIG. 7 , images indicating image contents using rectangles with image content identification information (# 6 , # 8  to # 10 , and # 13 ) are schematically shown. Thus, it is possible to display each image on the input/output panel  101  based on the user manipulation. Here, when the representative image (e.g., # 9 ) of the grouped image content is displayed on the input/output panel  101  as shown in  FIG. 7(   a ), manipulation support information  261  for setting the group image display mode is displayed. This manipulation support information  261  is the same as the manipulation support information  261  shown in  FIG. 5 . That is, the user can set the group image display mode by pressing a rectangular area corresponding to the manipulation support information  261 . For example, the group image display mode is set when the manipulation support information  261  is pressed in a state in which representative images (e.g., # 3  and # 9 ) of the grouped image contents are displayed on the input/output panel  101 . Thus, the manipulation to press the manipulation support information  261  becomes an entrance to the group image display mode. Where the group image display mode is set, the images contents belonging to the group corresponding to the representative image displayed when the group image display mode setting manipulation (a manipulation to press the manipulation support information  401 ) is performed are sequentially displayed. 
         [0099]    On the other hand, when the non-grouped image contents (e.g., # 6  and # 13 ) are displayed on the input/output panel  101  as shown in  FIG. 7(   a ), the manipulation support information  261  is not displayed. Accordingly, the manipulation to press the manipulation support information  261  will not be performed and the group image display mode will not be set in a state in which the non-grouped image contents (e.g., # 6  and # 13 ) have been displayed on the input/output panel  101 . 
         [0100]    Here, a case in which a group image display mode setting manipulation (the manipulation to press the manipulation support information  261 ) is performed in a state in which the representative image (# 9 ) of the grouped image content has been displayed on the input/output panel  101  is assumed. In this case, the group image reproduction unit  160  acquires image contents belonging to the group corresponding to the representative image displayed when the group image display mode setting manipulation is performed, from the image content storage unit  200 . Further, the group image reproduction unit  160  acquires image management information associated with each image content belonging to the group from the image management information storage unit  210 . Subsequently, the manipulation method determination unit  180  determines an image that is an object to be displayed (an image to be displayed) selecting from each image content belonging to the group based on the acquired image management information as well as determining a manipulation method for displaying these images to be displayed. The method of determining this images to be displayed and the method of determining the manipulation method thereof will be described in detail with reference to  FIGS. 8A to 14 . 
         [0101]    Subsequently, the group image reproduction unit  160  renders each image in the rendering memory  170  based on the acquired image content. In this case, the group image reproduction unit  160  renders each image in the rendering memory  170  according a predetermined rule (e.g., the order of image content identification information). An image rendering example in the rendering memory  170  is shown in  FIG. 6(   c ). 
         [0102]    In  FIG. 6(   c ), a case in which the image contents belonging to the group corresponding to the representative image displayed when the group image display mode is set are rendered in the rendering memory  170  is schematically shown. When an image content rendering process is thus performed, the group image reproduction unit  160  displays the fact on the input/output panel  101  and does not perform a displaying process in the group image display mode. A display example in this case is shown in  FIG. 7(   b ). Note that  FIG. 6(   b ) shows an image rendering example when all of each image content belonging to a group # 105  has been determined as the image to be displayed. 
         [0103]    In  FIG. 7(   b ), a display example when the image content rendering process is performed directly after the group image display mode setting manipulation is performed is shown. For example, manipulation support information  402  indicating the image content rendering process superimposed on the representative image (# 9 ) displayed when the group image display mode is set is displayed on the input/output panel  101 . When the image content rendering process is terminated, the group image reproduction unit  160  displays manipulation support information for supporting the image display switching manipulation in the group image display mode on the input/output panel  101 . The display example is shown in  FIG. 7(   c ). 
         [0104]    In  FIG. 7(   c ), a display example when the image content rendering process is terminated after the group image display mode setting manipulation is performed is shown. For example, manipulation support information  403  and  404  for supporting the image display switching manipulation in the group image display mode superimposed on the representative image (# 9 ) displayed when the group image display mode is set is displayed on the input/output panel  101 . The manipulation support information  403  and  404  is manipulation guides for supporting a manipulation for displaying each image in the group displayed on the input/output panel  101 . The manipulation support information  404  shown in  FIG. 7(   c ) is for supporting manipulation when the user performs a manipulation to rotate the imaging device  100  about the arrow  300  ( 301 ) shown in  FIG. 1A  in a state in which the user holds the imaging device  100  in his or her hand. Further, the manipulation support information  403  is manipulation support information to be displayed at first, which can be deleted by the user&#39;s operation or after a certain period time has elapsed. That is, when it is recognized that the user understands the meaning of the message, the message will be deleted. By deleting in this way, it is possible to notify the user that a manipulation to tilt is a right manipulation. Note that each of figures shows each of manipulation support information relatively large, for ease of explanation. 
         [0105]    Here, as shown in  FIG. 7(   c ), a setting manipulation to set the representative image display mode in a state in which the group image display mode is set and the manipulation support information  403  and  404  superimposed on the image to be displayed is displayed will be described. When the representative image display mode is set in this state, for example, the user performs a touch manipulation to contact the display surface of the input/output panel  101 . When the touch manipulation is performed, the mode is switched from the group image display mode to the representative image display mode (i.e., the representative image display mode is set), as shown by the arrow  405 . Directly after the representative image display mode is set as such, a representative image (e.g., image # 9 ) of the group displayed upon setting of the group image display mode is displayed. The representative image display mode may be set by a setting manipulation using the manipulation member, as well as the touch manipulation in the input/output panel  101 . 
       Assignment Example of Angle Information 
       [0106]      FIGS. 8A and 8B  shows one example of a position relationship between the subject and the imaging device  100  in an imaging operation performed using the imaging device  100  and an imaged image group generated in the imaging operation in the first embodiment of the present invention. 
         [0107]    In  FIG. 8A , a position relationship between the target subject (the face of the person  500 ) and the imaging device  100  in the imaging operation performed using the imaging device  100  is schematically shown. In the example shown in  FIG. 8A , an example in which the face of the person  500  is a target subject and the imaging operation is performed by moving the imaging device  100  to change a view with respect to the face of the person  500  is shown. Specifically, in  FIG. 8A , a case in which the front of the person  500  is photographed (when the angle information Ai in the imaging operation is 0 degree) is shown. Similarly, in  FIG. 8A , a case in which a right oblique side of the person  500  is photographed (the angle information Ai in the imaging operation is −60 degrees) and a case in which a left oblique side of the person  500  is photographed (the angle information Ai in the imaging operation is +60 degrees) are shown. In  FIG. 8A , for example, a face relating to the person  500  (including the person  500  included in each image) is shown in a simplified form. Further, the angle information Ai in the imaging operation performed using the imaging device  100  is shown below the imaging devices  100  (Ai=−60 degrees, Ai=0 degree and Ai=+60 degrees). 
         [0108]    In  FIG. 8B , an imaged image group (the images (C 0  to C 5 )  510  to  515 ) generated by the imaging device  100  is shown. Ci is identification information for identifying each image, and i is an integer satisfying 0&lt;=i&lt;=n. In the example shown in  FIG. 8B , n=5. 
         [0109]    Specifically, the images (C 0  to C 2 )  510  to  512  are imaged images when the right oblique side of the person  500  is photographed (when the angle information Ai in the imaging operation is −60 degrees, −55 degrees, and −25 degrees). Further, the images (C 3  to C 5 )  513  to  515  are imaged images when the left oblique side of the person  500  is photographed (when the angle information Ai in the imaging operation is +40 degrees, +55 degrees, and +60 degrees). In  FIG. 8B , for example, the face relating to the person  500  included in the images (C 0  to C 5 )  510  to  515  is shown in a simplified form, similar to  FIG. 8A . Further, the angle information Ai in the imaging operation (an angle in the imaging operation of the image Ci) is indicated below each image (A 0 =−60 degrees, A 1 =−55 degrees, . . . , A 4 =+55 degrees, A 5 =+60 degrees). 
         [0110]    Thus, the images (C 0  to C 5 )  510  to  515  generated by changing a view with respect to the target subject (the face of the person  500 ) are grouped as a multi-view image and stored in the image content storage unit  200 . Further, such image management information (e.g., the angle information and the group type) is stored in the image management information storage unit  210 . When the images (C 0  to C 5 )  510  to  515  are displayed using the imaging device  100 , the images (C 0  to C 5 )  510  to  515  in the group can be sequentially displayed by horizontally rotating the imaging device  100 . 
         [0111]    Here, the images (C 0  to C 5 )  510  to  515  are images obtained by imaging a face of the same person from different views. Accordingly, the user can obtain the feeling of viewing a three dimensional object (the face of the person  500 ) by rapidly performing the user manipulation to tilt the imaging device  100  to the left and right and rapidly performing image advancing or image returning. That is, the user manipulation to tilt the imaging device  100  to the left and right gives the user the feeling of viewing a pseudo-three-dimensional image. 
         [0112]    Thus, it is possible to enjoy a pseudo-three-dimensional image as a profound image by performing high-speed image advancing or image returning by a gesture manipulation of the user on the image group obtained by photographing the target subject from several angles. That is, when the user desires to three-dimensionally view the object, such as a face of a person or a vehicle, he or she can easily view a pseudo-three-dimensional image of the object through a manual manipulation. 
         [0113]    When the image group is displayed as such, a determination of the angle information (the overall rotation angle range and the reference angle) associated with the manipulation method is important. Hereinafter, a method of determining the angle information associated with the manipulation method will be described in detail with reference to the drawings. 
       Normalization Example of Angle Information 
       [0114]      FIGS. 9A to 9C  shows one example of a change of the posture of the imaging device  100  and normalization of the angle information performed by the manipulation method determination unit  180  in the first embodiment of the present invention. In  FIG. 9A , a transition example of the imaging device  100  in the case in which the image contents stored in the image content storage unit  200  are displayed when the group image display mode has been set is shown. In the example shown in  FIG. 9A , an appearance at a bottom side of the imaging device  100  (i.e., a surface opposite to a surface on which the shutter button  102  is provided) is shown. Similarly, in  FIGS. 9B ,  10 ( b ) and  13 ( a ), the appearance at the bottom side of the imaging device  100  is shown. 
         [0115]    In  FIG. 9B , a manipulation range (the overall range of the rotation angle) of the imaging device  100  corresponding to the transition of the imaging device  100  is schematically shown. In this example, an example in which image advancing or image returning is performed by rotating the imaging device  100  about the arrow  300  ( 301 ) shown in  FIGS. 1A and 1B  to change the posture is shown. In this case, the tilt angle (reference angle) as a reference when image advancing or image returning is performed is Vi. The tilt angle Vi may be obtained by Equation 1: 
         [0000]        Vi =(gamma)* j   Equation 1
 
         [0116]    Here, (gamma) is a value indicating tilt accuracy that can be maintained by a person, for example, without hand shaking. Such a value may be determined in consideration of accuracy or performance of the posture detection unit  120  (a tilt detection device). Further, j is a value satisfying (integer of −m&lt;=j&lt;=m), and i is an integer satisfying 0&lt;=i&lt;=n. In the example shown in  FIG. 9B , n=4. 
         [0117]    Here, the angle information Ai assigned to each image Ci in the image group is an angle with respect to the target subject in an imaging operation. Accordingly, it is preferable to associate each image Ci with the tilt angle Vi based on the angle information Ai. The angle information Ai is normalized so that the angle information Ai corresponds to the tilt angle Vi. Specifically, the normalization angle information Bi for which the angle information Ai has been normalized may be obtained by Equation 2: 
         [0000]        Bi =( V max/ Aabs )* Ai   Equation 2
 
         [0118]    Here, Vmax is an absolute value of a maximum tilt angle and is an angle at which a user is allowed to view the display screen. Vmax is limited to, for example, a viewing angle of the screen. Further, Aabs is a value (absolute value) indicating a range of the angle information Ai. 
         [0119]    In the example shown in  FIG. 9B , an example in which Vmax=180 degrees, (gamma)=45 degrees, and m=2 (i.e., −2&lt;=j&lt;=2) is shown. Further, the range of the angle information Ai is specified by the angle information A 0 (=−60 degrees) of the image (C 0 )  510  and the angle information A 5 (=+60 degrees) of the image (C 5 )  515 . That is, Aabs=|−60 degrees−60 degrees|=120 degrees. 
         [0120]    Accordingly, in the example shown in  FIG. 9B , B 0 =(180 degrees (Vmax)/120 degrees (Aabs))*(−60 degrees (A 0 ))=−90 degrees. Similarly, B 1 =−82.5 degrees, B 2 =−37.5 degrees, B 3 =60 degrees, B 4 =82.5 degrees, and B 5 =90 degrees. Such normalization angle information Bi is calculated by the manipulation method determination unit  180 . 
         [0121]    In  FIG. 9C , the images (C 0  to C 5 )  510  to  515 , angle information Ai assigned to the images and normalization angle information Bi calculated for the images are associated with one another and shown. 
         [0122]    The image Ci can be properly assigned to the tilt angle (reference angle) Vi by normalizing the angle information in the imaging operation associated with the image Ci. 
       Association Example Between Images to be Displayed and Tilt Angle 
       [0123]      FIG. 10  shows one example of a method of associating images to be displayed and the tilt angle range in the manipulation method determination unit  180 , and the images displayed after the association and manipulation support information in the first embodiment of the present invention. In  FIGS. 10(   a ) and ( b ), the method of associating the images to be displayed and the tilt angle range in the manipulation method determination unit  180  is schematically shown. 
         [0124]    In  FIG. 10(   a ), images (C 0  to C 5 )  510  to  515 , angle information Ai assigned to the images, and normalization angle information Bi calculated for the images are associated with one another and shown. The example shown in  FIG. 10(   a ) is the same as that shown in  FIG. 9C  except that a contour corresponding to a rectangle and a person  500  corresponding to the image (C 1 )  511  is indicated by a dotted line. 
         [0125]    In  FIG. 10(   b ), a manipulation range of the imaging device  100  (an overall range of the rotation angle) corresponding to a transition of the imaging device  100  is schematically shown. The example shown in  FIG. 10(   b ) is the same as that shown in  FIG. 9B . 
         [0126]    Here, in the example shown in  FIGS. 10(   a ) and ( b ), the number of the images (C 0  to C 5 )  510  to  515  ( 6 ) is greater than the number of tilt angles (reference angles) Vi ( 5 ). When the number of images belonging to the group to be displayed is greater than the number of tilt angles (reference angles) Vi, an interleaving process is performed on the images belonging to the group to be displayed. That is, the manipulation method determination unit  180  extracts a predetermined number of images from among the images belonging to the group to be displayed, as images to be displayed, so that the number of the images is in the range of the number of tilt angles (reference angles) Vi. 
         [0127]    Specifically, the image Ci associated with the normalization angle information Bi closest to the tilt angle (reference angle) Vi is selected as an image CCi for each tilt angle (reference angle) Vi from the image group (image Ci (0&lt;=i&lt;=n)) for which the normalization angle information Bi has been calculated. 
         [0128]    In  FIG. 10 , an example in which the image Ci associated with the normalization angle information Bi closest to the tilt angle (reference angle) Vi from the tilt angle (reference angle) V 0  to V 4  is selected, and the selected image Ci and the tilt angle (reference angle) Vi are associated with each other is shown. 
         [0129]    Specifically, the image C 0  associated with the normalization angle information B 0 (=−90 degrees) closest to the tilt angle V 0 (=−90 degrees) is selected and associated with the tilt angle V 0 , as an image CC 0 . Similarly, the image C 2  associated with the normalization angle information B 2 (=−37.5 degrees) closest to the tilt angle V 1 (=−45 degrees) is selected and associated with the tilt angle V 1 , as an image CC 1 . Further, the image C 3  associated with the normalization angle information B 3 (=+60 degrees) closest to the tilt angle V 2 (=0 degree) is selected and associated with the tilt angle V 2 , as an image CC 2 . Further, the image C 4  associated with the normalization angle information B 4 (=+82.5 degrees) closest to the tilt angle V 3 (=45 degrees) is selected and associated with the tilt angle V 3 , as an image CC 3 . Further, the image C 5  associated with the normalization angle information B 5 (=+90 degrees) closest to the tilt angle V 4 (=90 degrees) is selected and associated with the tilt angle V 4  as an image CC 4 . 
         [0130]    That is, CCi(={C 0 , C 2 , C 3 , C 4 , C 5 }={CC 0 , CC 1 , CC 2 , CC 3 , CC 4 }) is selected from the image group (image Ci (0&lt;=i&lt;=5)). 
         [0131]    The selected images CCi associated with the tilt angles Vi are sequentially displayed according to the tilt of the imaging device  100 . For example, when the posture of the imaging device  100  is in a state of the tilt angle (reference angle) Vi, the image CCi associated with the tilt angle (reference angle) V is displayed. The image CCi continues to be displayed until the posture of the imaging device  100  becomes the tilt angle (reference angle) Vi−1 or the tilt angle (reference angle) Vi+1. 
         [0132]    In  FIG. 10(   c ), a display example when each image CCi associated with the tilt angle Vi by the association method shown in  FIG. 10  are displayed on the input/output panel  101  is shown. In the example shown in  FIG. 10(   c ), an example in which manipulation support information  520  superimposed on the image to be displayed (the image CCi associated with the tilt angle Vi) is displayed is shown. 
         [0133]    The manipulation support information  520  is an indicator indicating a relationship between the images belonging to the group to be displayed (all extracted images to be displayed) and images displayed on the input/output panel  101  when the group image display mode has been set. Specifically, the manipulation support information  520  indicates the relationship between all the extracted images to be displayed (C 0  and C 2  to C 5 )  510 , and  512  to  515  and one image displayed on the input/output panel  101 . For example, a rectangular area in the manipulation support information  520  corresponding to one image displayed on the input/output panel  101  among all the images (C 0  and C 2  to C 5 )  510  and  512  to  515  has a different display aspect from other areas. In the example shown in  FIG. 10(   c ), corresponding symbols (V 0  to V 4 ) are added to rectangles indicating the manipulation support information  520 , for ease of explanation. 
         [0134]    That is, in the state shown in  FIG. 10(   c ), a state in which the image (C 3 )  513  among the images to be displayed (C 0  and C 2  to C 5 )  510  and  512  to  515  is displayed on the input/output panel  101  is shown. Further, when the imaging device  100  is rotated to the left and exceeds V 1  shown in  FIG. 10(   b ), the rectangular area V 1  in the manipulation support information  520  has a different display aspect from the other areas. Further, when the imaging device  100  is rotated to the left and exceeds V 0  shown in  FIG. 10(   b ), the rectangular area V 0  in the manipulation support information  520  has a different display aspect from the other areas. On the other hand, when the imaging device  100  is rotated to the right and exceeds V 3  and V 4  shown in  FIG. 10(   b ), the rectangular areas V 3  and V 4  in the manipulation support information  520  similarly have different display aspects from the other areas. 
         [0135]    Thus, when the group image display mode has been set, the total number of images to be displayed and a position of a display image in all the images to be displayed (a position in a display order) can be easily recognized by displaying both the image to be displayed and the indicator. 
         [0136]    In the foregoing, the example in which the angle information assigned to each image is normalized, the images are assigned to the angles at certain intervals, and the images are displayed according to the angles has been shown. Here, the tilt angle (reference angle) may be determined according to the interval of the calculated normalization angle information of each image and each image may be displayed according to the angle. Further, when the indicator is displayed as the manipulation support information, the display area of the indicator may be calculated according to the interval of the calculated normalization angle information of each image. A method of calculating the display area of the indicator and a display example are shown in  FIGS. 11 and 12 . 
       (Variant of Indicator Display) 
       [0137]      FIG. 11  schematically shows a method of calculating the display area of the indicator in the manipulation method determination unit  180  in the first embodiment of the present invention. 
         [0138]    In  FIG. 11(   a ), images (C 0  to C 5 )  510  to  515 , angle information Ai assigned to the images, and normalization angle information Bi calculated for the images are associated with one another and shown. Since the example shown in  FIG. 11(   a ) is the same as that shown in  FIG. 10(   a ), a description thereof will be omitted herein. 
         [0139]    In  FIG. 11(   b ), a relationship between the calculated display area and the indicator is schematically shown. For example, the manipulation method determination unit  180  performs normalization on the normalization angle information Bi calculated for the images (C 0  to C 5 )  510  to  515 . Specifically, the manipulation method determination unit  180  calculates the normalization angle information BBi(=normalization angle information of CCi+90 degrees). The display area Wi of the indicator may be obtained by Equation 3 using the normalization angle information BBi. 
         [0000]        Wi=BBi/V max* L   Equation 3
 
         [0140]    Here, L is a value indicating a length of the indicator displayed on the input/output panel  101 . Further, BBi is a value calculated by the above-described normalization. 
         [0141]    Here, the display area Wi of the indicator is a value indicating a length from a left end in the indicator (a length L) shown in  FIG. 11(   b ). A display example based on the calculated display area Wi of the indicator is shown in  FIG. 12 . 
         [0142]      FIG. 12  shows a display example of the indicator based on the display area of the indicator calculated by the manipulation method determination unit  180  in the first embodiment of the present invention. 
         [0143]    In  FIG. 12(   a ), the relationship between the display area Wi calculated in the example shown in  FIG. 11  and the indicator is schematically shown. The example shown in  FIG. 12(   a ) is the same as that shown in  FIG. 11(   b ) except that symbols (C 0  and C 2  to C 5 ) of images are added to rectangles corresponding to positions on the indicator specified by the display area Wi calculated in the example shown in  FIG. 11 . 
         [0144]    In  FIG. 12(   b ), a state in which an indicator (manipulation support information)  530  corresponding to the relationship between the display area Wi and the indicator shown in  FIG. 12(   a ) is displayed on the input/output panel  101  is shown. In the example shown in  FIG. 12(   b ), a state in which an area corresponding to the image (C 3 )  513  has a different display aspect from other areas is shown. 
         [0145]    In  FIG. 12(   c ) to ( f ), a display state on the input/output panel  101  of the indicator  530  corresponding to the relationship between the display area Wi and the indicator shown in  FIG. 12(   a ) is shown. In the example shown in  FIG. 12(   c ), a state in which an area corresponding to the image (C 2 )  512  has a different display aspect from the other areas is shown, and in the example shown in  FIG. 12(   d ), a state in which an area corresponding to the image (C 0 )  510  has a different display aspect from the other areas is shown. Further, in the example shown in  FIG. 12(   e ), a state in which an area corresponding to the image (C 4 )  514  has a different display aspect from the other areas is shown, and in the example shown in  FIG. 12(   f ), a state in which an area corresponding to the image (C 5 )  515  has a different display aspect from the other areas is shown. 
         [0146]    In the above description, the case in which image contents stored to be associated with the angle information are displayed has been described by way of example. However, a case in which image contents in which angle information is not recorded in an imaging operation are displayed is assumed. Hereinafter, the case in which the image contents in which angle information is not recorded in the imaging operation is displayed will be described. 
       Determination Example of the Number of Images to be Displayed and Interleaving Example of Images to be Displayed 
       [0147]      FIG. 13  schematically shows a method of determining the number of images to be displayed and a method of interleaving the images to be displayed in the manipulation method determination unit  180  in the first embodiment of the present invention. 
         [0148]    Here, if the number of images to be displayed is great in the case in which image content in which angle information is not recorded in an imaging operation is displayed, image advancing or image returning is likely to be performed even when a tilt manipulation of the imaging device  100  by a user is small. In this case, unintentional image advancing or image returning is assumed to be performed. In the case in which image content in which the angle information is not recorded in the imaging operation is displayed, the number of images to be displayed is determined according to a range in which the tilt manipulation of the imaging device  100  can be performed by the user, and only the images to be displayed are displayed. 
         [0149]    In  FIG. 13(   a ), a manipulation range (overall rotation angle range) of the imaging device  100  corresponding to the transition of the imaging device  100  is schematically shown. The manipulation range of the imaging device  100  shown in  FIG. 13(   a ) is substantially the same as that shown in  FIG. 9B , for example. 
         [0150]    For example, when the manipulation method determination unit  180  determines the number M of images to be displayed, the manipulation method determination unit  180  may obtain the number M using Equation 4. 
         [0000]        M=V max/(gamma)+1  Equation 4
 
         [0151]    Here, M is a value indicating the number of images that can be displayed. Further, Vmax is an absolute value of a maximum tilt angle, similar to Equation 2. Further, (gamma) is a value indicating tilt accuracy that can be maintained by a person, for example, without hand shaking, similar to Equation 1. 
         [0152]    In the example shown in  FIG. 13(   a ), the angle Vmax is assumed to be 180 degrees and the angle (gamma) is assumed to be 45 degrees. In this case, the number of the images to be displayed is calculated as M=5((180 degrees/45 degrees)+1). Further, the images belonging to the group to be displayed are images (C 0  to C 5 )  510  to  515  shown in  FIG. 13(   b ). 
         [0153]    Here, in the example shown in  FIG. 13 , the number of the images (C 0  to C 5 )  510  to  515  ( 6 ) is greater than the number M of images to be displayed ( 5 ). When the number of images belonging to the group to be displayed is greater than the number M of images to be displayed ( 5 ), it is necessary to perform interleaving so that the number of images to be displayed is equal to or less than the number M of images to be displayed. In  FIG. 13(   b ), the interleaving process (an extracting process) will be described. 
         [0154]    In  FIG. 13(   b ), a flow of the interleaving process of images to be displayed is shown. In this example, an example in which five images are extracted from the six images (images C 0  to C 5 ) when 5 is determined as the number M of the images to be displayed is shown. 
         [0155]    For example, when the manipulation method determination unit  180  extracts the images to be displayed, Equation 5 is calculated for each image Ci belonging to the group to be displayed. 
         [0000]        i  mod  D &lt;( D−M )  Equation 5
 
         [0156]    Here, x mod y is a value indicating x divided by y. Further, D is the number of images to be displayed and M is the number of images that can be displayed. 
         [0157]    Specifically, the manipulation method determination unit  180  determines whether i mod D&lt;(D−M) is satisfied for each image Ci belonging to the group to be displayed. The manipulation method determination unit  180  removes the image Ci for which i mod D&lt;(D−M) is satisfied from among the images to be displayed. That is, the manipulation method determination unit  180  extracts the image Ci for which i mod D&lt;(D−M) is not satisfied, as the image to be displayed, and uses the extracted image Ci as an image CCi. 
         [0158]    For example, in the example shown in  FIG. 13(   b ), since D=6, M=5, and D−M=1, the image C 0  is excluded from the images to be displayed. That is, CCi (={C 1 , C 2 , C 3 , C 4 , C 5 }={CC 0 , CC 1 , CC 2 , CC 3 , CC 4 }) is extracted from among the image group (image Ci (0&lt;=i&lt;=5)). 
         [0159]    In  FIG. 13(   c ), an example in which the extracted image CCi and the tilt angle (reference angle) Vi are associated with each other is schematically shown. As shown in  FIG. 13(   c ), the extracted CCi={C 1 , C 2 , C 3 , C 4 , C 5 } is assigned to the tilt angle (reference angle) Vi, and image CCi is associated with the tilt angle (reference angle) Vi. 
       Display Area Setting Example of Indicator 
       [0160]      FIG. 14  schematically shows a method of setting the display area of the indicator in the manipulation method determination unit  180  according to the first embodiment of the present invention. In  FIG. 14(   a ), the images (C 1  to C 5 )  511  to  515  extracted in the example shown in  FIG. 13  are shown. 
         [0161]    In  FIG. 14(   b ), a relationship between the set display area and the indicator is schematically shown. When the image contents in which the angle information is not recorded in the imaging operation are displayed as shown in  FIG. 13 , the image contents are assigned to the tilt angles (reference angles) Vi at certain intervals. Accordingly, even when the display area of the indicator is set as shown in  FIG. 14(   b ), the image contents may be associated with the tilt angles (reference angles) Vi and assigned at certain intervals. 
         [0162]    In the foregoing, the example in which the images to be displayed, and the manipulation support information (e.g., the indicator) indicating the total number of images to be displayed and the display image positions (positions in a display order) in all the images are displayed when the group image display mode has been set has been shown. Here, the images to be displayed, and manipulation support information (e.g., tilt meter) indicating the relationship between the posture of the imaging device  100  and image advancing or image returning may be displayed. Further, such manipulation support information (e.g., the indicator and the tilt meter) may be simultaneously displayed. Hereinafter, an example in which the manipulation support information (tilt meter) the relationship between the posture of the imaging device  100  and image advancing or image returning is displayed will be described. 
       Display Transition Example of Tilt Meter Based on Rotation Angle 
       [0163]      FIG. 15  shows a display transition example of manipulation support information (a tilt meter) displayed by the group image reproduction unit  160  in the first embodiment of the present invention. In this example, a display transition example when image advancing or image returning is performed according to the rotation angle of the imaging device  100  is shown. Further, in this example, an example in which the reference angle when image advancing or image returning is performed is 20 degrees and image advancing or image returning is performed each time the tilt angle of the imaging device  100  exceeds 20 degrees is shown. In the example shown in  FIGS. 15 to 17C , a corresponding angle is indicated on each rectangle of the tilt meter. 
         [0164]    In  FIG. 15(   a ), a transition of the imaging device  100  when the imaging device  100  is tilted to the right by the user is shown. In  FIG. 15(   b ), when the imaging device  100  is tilted to the right by the user, a display transition of the tilt meter displayed according to the tilt angle is shown.  FIGS. 15(   a ) and ( b ) correspond to each other, but a portion of  FIG. 15(   b ) is omitted. 
         [0165]    For example, a state  611  shown in the top of  FIG. 15(   a ) is a state in which the imaging device  100  exists on the same plane as a horizontal plane  330 . In this case, as shown in the state  601  in the top of  FIG. 15(   b ), only a rectangular area at a middle portion of the tilt meter has a different display aspect (e.g., black color) from other areas. Hereinafter, the different display aspect from the other areas is referred to as a black color. 
         [0166]    For example, as in states  612  and  613  shown in  FIG. 15(   a ), a case in which the user rotates the imaging device  100  to the right in a state in which the user holds the imaging device  100  is assumed. In this case, when the rotation angle (theta) at which the imaging device  100  is rotated to the right reaches 5 degrees, the two rectangular areas at the right from the middle of the tilt meter become black as shown in a state  602  of  FIG. 15(   b ), but image advancing is not performed. Further, when the user rotates the imaging device  100  to the right in a state in which the user holds the imaging device  100 , the rectangular areas at the right from the middle of the tilt meter become sequentially black according to the rotation angle (theta). Specifically, when the rotation angle (theta) reaches 10 degrees, the two rectangular areas at the right from the middle of the tilt meter become black (state  603 ), and when the rotation angle (theta) reaches 15 degrees, the three rectangular areas at the right from the middle of the tilt meter become black (state  604 ). Here, in the case of the state  601  to  604 , image advancing is not performed. 
         [0167]    Subsequently, when the rotation angle (theta) at which the imaging device  100  is rotated to the right reaches 20 degrees, all the portions at the right from the middle of the tilt meter are black as shown in a state  605 , and an indication of reaching the tilt of image advancing is displayed and image advancing is performed. 
         [0168]    After image advancing is performed and a next image is displayed on the input/output panel  101 , only the rectangular area in the middle portion of the tilt meter becomes black as shown in state  606 . That is, the tilt meter in the state  606  becomes the same as the state in which the imaging device  100  exists on the same plane as the horizontal plane  330  (state  601 ). 
         [0169]    Similarly, when the user rotates the imaging device  100  to the right rotation in a state in which the user holds the imaging device  100 , the rectangular area in the tilt meter becomes black according to the rotation angle (theta), as shown in states  607  and  608  of  FIG. 15(   b ). 
         [0170]    Here, when the imaging device  100  is rotated to the right to an angle at which the last image among the images to be displayed is sent, the tilt meter enters a state that is the same as the state  605 . Accordingly, even when further rotation to the right is performed, an indication indicating that image advancing is not performed may be notified of. 
         [0171]    Similarly, when the imaging device  100  is rotated to the left, the rectangular areas at the left from the middle of the tilt meter become sequentially black. 
         [0172]    While the example in which image advancing or image returning is performed each time the imaging device  100  exceeds the reference angle (e.g., 20 degrees) has been shown in the foregoing, image advancing or image returning may be performed by another manipulation method. Hereinafter, an example in which image advancing or image returning is performed by another manipulation method is shown. 
         [0173]      FIG. 16  shows a display transition example of the manipulation support information (the tilt meter) displayed by the group image reproduction unit  160  in the first embodiment of the present invention. In this example, a display transition example in which image advancing and image returning are sequentially performed when the rotation angle of the imaging device  100  reaches a certain angle and then such a state is maintained is shown. Further, in this example, an example in which image advancing is sequentially performed in the case in which the reference angle when image advancing or image returning is performed is 20 degrees and the tilt angle of the imaging device  100  is maintained at 20 degrees is shown. In  FIGS. 16 to 17C , the transition example of the imaging device  100  shown in  FIG. 15(   a ) is omitted. 
         [0174]    In  FIG. 16(   a ), a display transition of the tilt meter displayed according to the tilt angle when the imaging device  100  is tilted to the right by the user is shown. States  621  to  625  shown in  FIG. 16(   a ) correspond to the states  601  to  605  shown in  FIG. 15(   b ). That is, when the user rotates the imaging device  100  to the right in a state in which the user holds the imaging device  100  as in the state  612  and  613  of the imaging device  100  shown in  FIG. 15(   a ), the same states as the states  601  to  604  shown in  FIG. 15(   b ) are obtained. Further, in the case of the states  621  to  624 , image advancing is not performed. 
         [0175]    Subsequently, when the rotation angle (theta) at which the imaging device  100  is rotated to the right reaches 20 degrees, all right portions from a middle of the tilt meter become black as shown in the state  625 , an indication of reaching the tilt of image advancing is displayed, and image advancing is performed. 
         [0176]    In  FIG. 16(   b ), a display example of the tilt meter when the rotation angle (theta) at which the imaging device  100  is rotated to the right reaches 20 degrees and then the rotation angle (theta) is maintained (or when a state of the rotation angle (theta) or more is maintained) is shown. 
         [0177]    When the rotation angle (theta) at which the imaging device  100  is rotated to the right reaches 20 degrees and then the rotation angle (theta) is maintained, image advancing is performed, and after a next image is displayed on the input/output panel  101 , the state transitions to the state  626 . This state  626  is a state in which the state  625  is maintained. That is, the tilt meter in the state  626  becomes the same as the state (state  625 ) in which the rotation angle (theta) at which the imaging device  100  is rotated to the right reaches 20 degrees. Further, in the state in which the rotation angle (theta) is maintained, image advancing is performed at certain intervals. 
         [0178]    In  FIG. 16(   c ), a display example of the tilt meter when the rotation angle (theta) at which the imaging device  100  is rotated to the right reaches 20 degrees and then the rotation angle (theta) is returned is shown. 
         [0179]    When the rotation angle (theta) at which the imaging device  100  is rotated to the right reaches 20 degrees and then the rotation angle (theta) is returned (i.e., when the rotation angle (theta) is less than 20 degrees), image advancing is performed, a next image is displayed on the input/output panel  101 , and the state transitions to state  627 . That is, when the rotation angle (theta) at which the imaging device  100  is rotated to the right reaches 20 degrees and then the rotation angle (theta) is returned, the display of the tilt meter is returned according to the returned angle and image advancing is ceased. 
         [0180]    Similarly, when the imaging device  100  is rotated to the left, the rectangular areas at the left from the middle of the tilt meter become sequentially black. 
         [0181]    In the foregoing, an example in which image advancing or image returning is performed based on whether the rotation angle of the imaging device  100  exceeds a reference angle of image advancing or image returning has been shown. Here, for example, image advancing or image returning may be performed based on whether the rotational angular velocity of the imaging device  100  exceeds a reference. Hereinafter, an example in which image advancing or image returning is performed based on whether the rotational angular velocity of the imaging device  100  exceeds a reference will be described. 
       Display Transition Example of Tilt Meter Based on Rotational Angular Velocity 
       [0182]      FIGS. 17A to 17C  shows a display transition example of manipulation support information (a tilt meter) displayed by the group image reproduction unit  160  in the first embodiment of the present invention. In this example, a display transition example when image advancing or image returning is performed according to the rotational angular velocity (rotation angle/sec) of the imaging device  100  is shown. That is, in this example, an example in which image advancing or image returning is performed according to whether the device reaches a certain angular velocity by one rotation manipulation is shown. Further, in this example, an example in which the rotational angular velocity (rotation angle/sec) when image advancing or image returning is performed is 20 degrees/sec and image advancing or image returning is performed each time the rotational angular velocity of the imaging device  100  exceeds 20 degrees/sec is shown. 
         [0183]    In  FIG. 17A , a display transition of the tilt meter displayed according to a rotational angular velocity when the imaging device  100  is rotated at 5 degrees/sec to the right by the user is shown (states  631  and  632 ). In this case, since the rotational angular velocity does not reach 20 degrees/sec, image advancing is not performed and the original state is returned (i.e., the state is returned from the state  632  to the state  631 ). 
         [0184]    In  FIG. 17B , a display transition of the tilt meter displayed according to a rotational angular velocity when the imaging device  100  is rotated at 10 degrees/sec to the right by the user is shown (states  633  and  634 ). In this case, since the rotational angular velocity does not reach 20 degrees/sec, image advancing is not performed and the original state is returned (i.e., the state is returned from the state  634  to the state  633 ). Similarly, when the imaging device  100  is rotated at 15 degrees/sec to the right by the user, the display state of the tilt meter is changed according to the tilt angular velocity, but since the rotational angular velocity does not reach 20 degrees/sec, image advancing is not performed. Similarly, even in this case, the original state is returned. 
         [0185]    In  FIG. 17C , a display transition of the tilt meter displayed according to a rotational angular velocity when the imaging device  100  is rotated at 20 degrees/sec to the right by the user is shown. In this case, since the rotational angular velocity reaches 20 degrees/sec, image advancing is performed. When the image advancing is performed and then the state of such an angle is maintained (i.e., in the case of 0 degree/sec), the original state is returned (i.e., the state is returned from the state  636  to the state  637 ). Further, when the rotational angular velocity is maintained (or when a state of the rotational angular velocity or more is maintained), the display state of the tilt meter is maintained according to a maintained period and image advancing is sequentially performed. 
         [0186]    In  FIGS. 17B and 17C , some of a display transition from the state  633  to the state  634  and a display transition from the state  635  to the state  636  are omitted. 
         [0187]    Similarly, when the imaging device  100  is rotated to the left, the rectangular areas at the left from the middle of the tilt meter become sequentially black. 
       Display Example of Manipulation Support Information 
       [0188]      FIGS. 18 and 19  schematically show a relationship between a display transition in the input/output panel  101  and the posture of the imaging device  100  in the first embodiment of the present invention. 
         [0189]    In  FIG. 18 , a transition example when the manipulation support information (the indicator) superimposed on the image to be displayed is displayed on the input/output panel  101  is shown. Further, in  FIG. 19 , a transition example in which manipulation support information (tilt meter) superimposed on the image to be displayed is displayed on the input/output panel  101  is shown. Further, in  FIGS. 18(   b ) and  19 ( b ), a transition example of the posture of the imaging device  100  when an image is displayed on the input/output panel  101  is shown. In the examples shown in  FIGS. 18(   b ) and  19 ( b ), a transition example when the posture of the imaging device  100  upon setting of the group image display mode is located on the plane of a horizontal plane  330  is shown. Further, in  FIGS. 18 and 19 , images displayed on the input/output panel  101  shown in each of in  FIGS. 18(   a ) and  19 ( a ) and postures of the imaging device  100  shown in each of in  FIGS. 18(   b ) and  19 ( b ) are shown to show a corresponding relationship at the left and right. 
         [0190]    In  FIGS. 18(   a ) and  19 ( a ), the transition of the image displayed on the input/output panel  101  is shown. The images  651  to  653  displayed on the input/output panel  101  shown in  FIGS. 18(   a ) and  19 ( a ) are images obtained by imaging a face of the same person from different views. Accordingly, the user can obtain the feeling of viewing a three-dimensional object (a face of a person) by rapidly performing user manipulation to tilt the imaging device  100  to the left and right and rapidly performing image advancing or image returning. That is, the user manipulation to tilt the imaging device  100  to the left and right enables the user to obtain the feeling of viewing a pseudo-three-dimensional image. Further, the group to which the images  651  to  653  belong includes seven images (including the image  651  to  653 ). The image  651  is a representative image of the group and the images  652  and  653  are first and last images in a display order. 
         [0191]    First, the case in which the manipulation support information (the indicator) superimposed on the image to be displayed is displayed on the input/output panel  101  will be described with reference to  FIG. 18 . As described above, the representative image (image  651 ) is displayed on the input/output panel  101  directly after the group image display mode is set. In this case, the manipulation support information  403  superimposed on the image  651  is displayed, similar to  FIG. 7  C. Here, since the manipulation support information  403  is deleted or reduced when image advancing or image returning is performed for a certain time (or a certain number of times) by the user manipulation, the display example is omitted in  FIGS. 18(   a ) and  19 ( b ). 
         [0192]    Here, a case in which the image  652  is displayed on the input/output panel  101  when the group image display mode has been set is assumed. In this case, since the image  652  is a first image in a display order among the seven images in the same group, a rectangular area at a left end in the indicator  660  has a different display aspect from other rectangular areas. In this case, it is difficult to perform further image returning. 
         [0193]    Further, a case in which an image  653  is displayed on the input/output panel  101  when the group image display mode has been set is assumed. In this case, since the image  653  is a last image in the display order among the seven images in the same group, a rectangular area at a right end in the indicator  660  has a different display aspect from the other rectangular areas. In this case, it is difficult to perform further image advancing. 
         [0194]    Thus, a mark indicating order relating to the images displayed on the input/output panel  101  in all of the plurality of images (e.g., the order specified by the normalization angle information) can be displayed as the indicator. 
         [0195]    It is possible to easily recognize positions in a display order of images to be displayed in the group by displaying the images to be displayed and the indicator  660  when the group image display mode is set. Accordingly, it is possible to easily perform the image advancing or image returning manipulation while viewing the images to be displayed when performing the image advancing or image returning manipulation. 
         [0196]    Next, a case in which the manipulation support information (the tilt meter) superimposed on the image to be displayed is displayed on the input/output panel  101  will be described with reference to  FIG. 19 . 
         [0197]    Here, a case in which an image  652  is displayed on the input/output panel  101  when the group image display mode has been set is assumed. In this case, since the image  652  is a first image in the display order among the seven images in the same group, the rectangular areas from a middle of the tilt meter  670  to a left end have a different display aspect from the other rectangular areas. In this case, it is difficult to perform further image returning. 
         [0198]    Further, a case in which an image  653  is displayed on the input/output panel  101  when the group image display mode has been set is assumed. In this case, since the image  653  is a last image in the display order among the seven images in the same group, the rectangular areas from the middle of the tilt meter  670  to a right end have a different display aspect from the other rectangular areas. In this case, it is difficult to perform further image advancing. 
         [0199]    Thus, it is possible to display the mark indicating the change amount of the posture of the imaging device  100  necessary for changing the display state in the input/output panel  101 , as the tilt meter. That is, it is possible to display the mark indicating the change amount of the posture of the imaging device  100  necessary for performing image advancing or image returning on a plurality of images, as the tilt meter. 
         [0200]    Since the transition of the display state of the tilt meter  670  according to the tilt angle of the imaging device  100  is the same as the transition examples of  FIGS. 15 to 17C , a description thereof will be omitted herein. 
         [0201]    Thus, the user can easily recognize the tilt to display each image to be displayed by displaying the images to be displayed and the tilt meter  670  when the group image display mode has been set. Further, the user can easily recognize the positions in the display order of the images to be displayed in the group. Accordingly, the user can easily perform the image advancing or image returning manipulation while viewing the images to be displayed when performing the image advancing or image returning manipulation. 
       Operation Example of Imaging Device 
       [0202]      FIG. 20  and  FIG. 21  are flowcharts showing an example of a processing procedure of an image content reproduction process in the imaging device  100  according to the first embodiment of the present invention. 
         [0203]    First, a determination is made as to whether an image content display instruction manipulation is performed (step S 901 ), and when the display instruction manipulation is not performed, monitoring is continued. On the other hand, when the display instruction manipulation is performed (step S 901 ), the control unit  140  sets the representative image display mode and the representative image reproduction unit  150  displays a representative image and non-grouped images on the display unit  111  (step S 902 ). 
         [0204]    Subsequently, a determination is made as to whether the image advancing manipulation or image returning manipulation is performed in a state in which the representative image display mode has been set (step S 903 ). When the image advancing manipulation or the image returning manipulation is performed (step S 903 ), the representative image reproduction unit  150  performs display switching of the image displayed on the display unit  111  (step S 904 ). That is, image advancing or image returning of the image displayed on the display unit  111  is performed. 
         [0205]    When the image advancing manipulation or image returning manipulation is not performed (step S 903 ), a determination is made as to whether the group image display mode setting manipulation is performed (step S 905 ), and when the group image display mode setting manipulation is not performed, the process proceeds to step S 916 . On the other hand, when the group image display mode setting manipulation is performed (step S 905 ), a group image display mode setting process is performed (step S 920 ). The group image display mode setting process will be explained in detail with reference to  FIG. 22 . 
         [0206]    Subsequently, the group image reproduction unit  160  displays initial manipulation support information (e.g., the manipulation support information  403  shown in  FIG. 7(   c )) superimposed on the image on the display unit  111  (step S 906 ). That is, the group image reproduction unit  160  decodes the image content acquired from the image content storage unit  200 , and renders a display image in the rendering memory  170  based on the decoded image content. The group image reproduction unit  160  simultaneously displays one (representative image) of the images rendered in the rendering memory  170  and the initial manipulation support information on the display unit  111 . 
         [0207]    Subsequently, a determination is made as to whether the initial manipulation support information is displayed (step S 907 ), and when the initial manipulation support information is not displayed, the process proceeds to step S 910 . On the other hand, when the initial manipulation support information is displayed (step S 907 ), a determination is made as to whether a certain time elapses after the group image display mode is set (step S 908 ). When a certain time elapses after the group image display mode is set (step S 908 ), the group image reproduction unit  160  deletes the initial manipulation support information displayed on the display unit  111  (step S 909 ). On the other hand, when a certain time has not elapsed after the group image display mode is set (step S 908 ), a determination is made as to whether a tilt manipulation by the user is performed (step S 910 ). That is, the group image reproduction unit  160  determines whether the posture of the imaging device  100  is changed above a certain amount based on the analysis information output from the analysis unit  130 . 
         [0208]    When the tilt manipulation by the user is performed (step S 910 ), a determination is made as to whether the initial manipulation support information is displayed (step S 911 ), and when the initial manipulation support information is not displayed, the process proceeds to step S 913 . On the other hand, when the initial manipulation support information is displayed (step S 911 ), the group image reproduction unit  160  deletes the initial manipulation support information displayed on the display unit  111  (step S 912 ). 
         [0209]    Subsequently, the group image reproduction unit  160  changes the display state of the manipulation support information (the indicator or the tilt meter) based on the manipulation amount according to the tilt manipulation by the user and the display image (the image displayed on the display unit  111 ) (step S 913 ). Subsequently, when the manipulation amount according to the tilt manipulation by the user exceeds a display switching reference, the group image reproduction unit  160  performs display switching (image advancing or image returning) on the image displayed on the display unit  111  (step S 914 ), and the process returns to step S 907 . When the manipulation amount according to the tilt manipulation by the user does not exceed the display switching reference, the group image reproduction unit  160  does not perform display switching (image advancing or image returning) on the image displayed on the display unit  111  and the process returns to step S 907 . 
         [0210]    When a tilt manipulation by the user is not performed (step S 910 ), a determination is made as to whether the representative image display mode setting manipulation is performed (step S 915 ), and when the setting manipulation is performed, the process returns to step S 902 . On the other hand, when the representative image display mode setting manipulation is not performed (step S 915 ), a determination is made as to whether the image content display termination manipulation is performed (step S 916 ), and when the display termination manipulation is performed, the image content reproduction process operation is terminated. When the image content display termination manipulation is not performed (step S 916 ), a determination is made as to whether the group image display mode has been set (step S 917 ). When the group image display mode has been set (step S 917 ), the process returns to step S 907 , and when the group image display mode has not been set (that is, the representative image display mode has been set), the process returns to step S 903 . Steps S 906  to S 920  are one example of a control procedure defined in the claims. Step S 910  is one example of a detection procedure defined in the claims. 
         [0211]      FIG. 22  is a flowchart showing an example of a group image display mode setting process (a processing procedure in step S 920  shown in  FIG. 20 ) in a processing procedure of the image content reproduction process in the imaging device  100  according to the first embodiment of the present invention. 
         [0212]    First, the group image reproduction unit  160  acquires each image content belonging to a group corresponding to the representative image displayed on the display unit  111  upon a group image display mode setting manipulation from the image content storage unit  200  (step S 921 ). Further, the group image reproduction unit  160  acquires image management information associated with each image content belonging to the group from the image management information storage unit  210  (step S 921 ). 
         [0213]    Subsequently, the manipulation method determination unit  180  determines whether angle information is included in the acquired image management information (step S 922 ). When the angle information is included in the acquired image management information (step S 922 ), the manipulation method determination unit  180  normalizes the angle information included in the acquired image management information for each image content (step S 923 ). 
         [0214]    Subsequently, the manipulation method determination unit  180  associates the acquired image content with the tilt angle (the reference angle) based on the normalized angle information (normalization angle information) (step S 924 ). In this case, when the number of the acquired image contents is greater than the number of tilt angles (reference angles), the manipulation method determination unit  180  performs an interleaving process on the acquired image contents so that the number of image contents is in a range of the number of tilt angles (reference angles). Subsequently, the manipulation method determination unit  180  calculates the display area of the indicator based on a correspondence relationship resulting from the association (step S 925 ). 
         [0215]    Further, when the angle information is not included in the acquired image management information (step S 922 ), the manipulation method determination unit  180  determines whether the number of the acquired image contents is greater than the number of images that can be displayed (the number of tilt angles (reference angles)) (step S 926 ). When the number of acquired image contents is equal to or less than the number of images that can be displayed (step S 926 ), the process proceeds to step S 928 . On the other hand, when the number of the acquired image contents is greater than the number of images that can be displayed (step S 926 ), the manipulation method determination unit  180  performs an interleaving process on the acquired image contents so that the number of images is in a range of the number of images that can be displayed (step S 927 ). 
         [0216]    Subsequently, the manipulation method determination unit  180  associates the acquired image contents (or the image contents after the interleaving process) with the tilt angles (reference angles) (step S 928 ). The manipulation method determination unit  180  then calculates the display area of the indicator based on a correspondence relationship resulting from the association (step S 929 ). 
       2. Variant 
       [0217]    In the foregoing, the example in which the manipulation support information (the tilt meter or the indicator) structured by a rod-shaped rectangle is displayed as the manipulation support information has been shown. In the variant, an example of the manipulation support information (the tilt meter or the indicator) displayed with another structure is shown. The configuration of the imaging device  100  is the same as the first embodiment of the present invention except that the display aspect of the manipulation support information differs. Accordingly, hereinafter, a difference with the first embodiment of the present invention will be mainly described and a description of the same portions will be omitted. 
       Display Example of Tilt Meter 
       [0218]      FIGS. 23A and 23B  shows manipulation support information (a tilt meter) displayed by the group image reproduction unit  160  and a display transition example in the input/output panel  101  in the variant of the first embodiment of the present invention. 
         [0219]    In  FIG. 23A , one example of the manipulation support information (the tilt meter) structured in a circular shape is shown. Corresponding angles are indicated at outer sides of the circle constituting the tilt meter. Further, the tilt angle of the imaging device  100  is indicated by an arrow from a center of the circle constituting the tilt meter to the position on the circle corresponding to the tilt angle. 
         [0220]    In  FIG. 23B , a transition of the image displayed on the input/output panel  101  is shown. As described above, the representative image (image  701 ) is displayed on the input/output panel  101  directly after the group image display mode is set. In this case, manipulation support information  711  superimposed on the image  701  is displayed, similar to  FIG. 7  C. Here, the manipulation support information  711  may be deleted or reduced when image advancing or image returning is performed for a certain time (or a certain number of times) by the user manipulation. 
         [0221]    Further, in the example shown in  FIG. 23B , a display transition example when image advancing or image returning is performed according to the rotation angle of the imaging device  100  is shown. Further, in this example, an example in which the reference angle when image advancing or image returning is performed is 30 degrees and image advancing or image returning is performed each time the tilt angle of the imaging device  100  exceeds 30 degrees is shown. 
         [0222]    For example, a case in which the user rotates the imaging device  100  to the left in a state in which the user holds the imaging device  100  is assumed. For example, when an angle at which the imaging device  100  is rotated to the left reaches 20 degrees, the tilt meter  712  with an arrow from the center of the circle constituting the tilt meter to a position on the circle corresponding to the rotation angle (20 degrees) is displayed on the image  701 . Here, in this case, image advancing is not performed. Further, a case in which the user rotates the imaging device  100  to the left in a state in which the user holds the imaging device  100  and the rotation angle reaches 30 degrees is assumed. In this case, the tilt meter with an arrow from the center of the circle constituting the tilt meter to a position on the circle (a bottom of the circle) corresponding to the rotation angle (30 degrees) is displayed on the image  701 , an indication of reaching a tilt of image advancing is displayed, and image advancing is performed. 
         [0223]    Similarly, when the imaging device  100  is rotated to the right, a tilt meter  713  with an arrow from the center of the circle constituting the tilt meter to the position on the circle corresponding to the rotation angle is superimposed on the image  701  and displayed. 
         [0224]      FIGS. 24A and 24B  shows an example of manipulation support information (a tilt meter) displayed by the group image reproduction unit  160  and a display transition in the input/output panel  101  in the variant of the first embodiment of the present invention. 
         [0225]    In  FIG. 24A , an example of manipulation support information (a tilt meter) structured in a circular shape is shown. Corresponding rotational angular velocities are indicated at outer sides of the circle constituting the tilt meter. Further, the rotational angular velocity of the imaging device  100  is indicated by an arrow from the center of the circle constituting the tilt meter to a position on the circle corresponding to the rotational angular velocity. 
         [0226]    In  FIG. 24B , a transition of the image displayed on the input/output panel  101  is shown. This example is the same as that shown in  FIG. 23B  in that a representative image (an image  701 ) is displayed on the input/output panel  101  and manipulation support information  711  is superimposed on the image  701  and displayed. 
         [0227]    Further, in the example shown in  FIG. 24B , a display transition example when image advancing or image returning is performed according to the rotational angular velocity of the imaging device  100  is shown. Further, in this example, an example in which the rotational angular velocity (rotation angle/sec) when image advancing or image returning is performed is 20 degrees/sec and image advancing or image returning is performed each time the rotational angular velocity of the imaging device  100  reaches 20 degrees/sec is shown. 
         [0228]    For example, a case in which the user rotates the imaging device  100  to the left in a state in which the user holds the imaging device  100  and the rotational angular velocity reaches 20 degrees/sec is assumed. In this case, a tilt meter  721  with an arrow from the center of the circle constituting the tilt meter to a position on the circle corresponding to the rotational angular velocity (20 degrees/sec) is displayed on the image  701 , an indication of reaching a rotational angular velocity of image advancing is displayed, and image advancing is performed. The image  702  is displayed by image advancing. Further, when a state of the angle is maintained after image advancing (i.e., in the case of 0 degree/sec), the original state is returned. That is, a tilt meter  722  with an arrow from the center of the circle constituting the tilt meter to a position on the circle (a top of the circle) corresponding to the rotational angular velocity (0 degree/sec) is displayed on the image  702 . 
         [0229]    Similarly, when the imaging device  100  is rotated to the right, a tilt meter with an arrow from the center of the circle constituting the tilt meter to the position on the circle corresponding to the rotational angular velocity is displayed. 
         [0230]    In the tilt meter shown in  FIGS. 23A to 24B , a range of the top of the circle and a position on the circle indicated by the arrow (a range of a pan system specified by the two points and the center of the circle) may have a different display aspect from other areas to be easily recognized by the user. 
       Display Example of Indicator 
       [0231]      FIGS. 25 to 28  show a display transition example in the input/output panel  101  in the variant of the first embodiment of the present invention. In such an example, a variant of a display aspect of manipulation support information (indicator) displayed by the group image reproduction unit  160  is shown. Further, in  FIGS. 25 and 27 , an example in which display support information (e.g., icon)  802  and  812  indicating the type of a group to be displayed is displayed with the indicator is shown. 
         [0232]    In  FIGS. 25 and 26 , a display transition example when a multi-view image is displayed is shown. In  FIG. 25 , an example in which an indicator  801  and display support information  802  indicating that the type of a group to be displayed is “multi-view image” are simultaneously displayed is shown. In  FIG. 26 , an example in which an indicator  811  indicating that the type of a group to be displayed is “multi-view image” is displayed is shown. 
         [0233]    In  FIGS. 27 and 28 , a display transition example when a multi-shot image is displayed is shown. In  FIG. 27 , an example in which the indicator  821  and display support information  822  indicating that the type of the group to be displayed is a “multi-shot image” are simultaneously displayed is shown. In  FIG. 28 , an example in which an indicator  831  indicating that the type of the group to be displayed is a “multi-shot image” is displayed is shown. 
         [0234]    Since a display state in the indicator shown in  FIGS. 25 to 28  is the same as the example shown in  FIG. 18 , a description thereof will be omitted herein. 
         [0235]    Thus, based on the correlativity (e.g., corresponding to the group type) between the images in the image group associated with the image displayed on the input/output panel  101 , a display aspect of the indicator is changed from the image group to the image group and then the indicator is displayed. 
         [0236]    Further, the user can easily perform a manipulation to display each image to be displayed by displaying the image to be displayed and the display support information indicating the type of the group to be displayed when the group image display mode has been set. That is, when image advancing or image returning manipulation is performed, the user can easily perform the manipulation while viewing the image to be displayed. 
         [0237]    As described above, in the embodiment of the present invention, the initial manipulation support information (e.g., the manipulation support information  403  shown in  FIG. 7(   c )) is displayed upon setting of the group image display mode. Accordingly, it is possible to prevent a desired image from missing due to, for example, a bad way of holding the imaging device  100  and switching of a displayed view upon initiation of image reading. 
         [0238]    Further, for example, the user can easily recognize a tilt angle at which a view is switched by displaying the tilt meter when the multi-view image is displayed upon setting of the group image display mode. Further, for example, even when an image in which a change of a switched view is small is displayed, the user can easily recognize that the image is switched by the user performing a manipulation to tilt the device. 
         [0239]    Further, for example, the user can easily recognize one of all views to which a currently displayed view corresponds by displaying the indicator when the multi-view image is displayed upon setting of the group image display mode. Further, for example, when an image of a view photographed from a rightmost side is displayed, the user can easily recognize that the view is not switched even though a right side is further tilted down. 
         [0240]    In the example shown above, the example in which the display state in the input/output panel  101  is changed by rotating the imaging device  100  about the vertical direction of the imaging device  100  has been shown. Here, the embodiment of the present invention may be applied to a case in which the display state in the input/output panel  101  is changed by rotating the imaging device  100  about the horizontal direction of the imaging device  100 . In this case, for example, the image may be changed by up and down tilt manipulations, and the indicator or the tilt meter may be vertically arranged and displayed. Further, for example, when an image in which there is a view in both directions of up and down and left and right is displayed, view switching may be performed by a tilt manipulation in both directions of up and down and left and right, and the indicator or the tilt meter may be displayed for both directions of up and down and left and right. The embodiment of the present invention may also be applied to a case in which the display state in the input/output panel  101  is changed by sliding (parallel movement) toward any of up, down, left, right, backward and forward directions of the imaging device  100 . 
         [0241]    While the imaging device has been described by way of example in the embodiments of the present invention, the embodiments of the present invention may be applied to an image processing device capable of displaying image contents stored in the recording medium on the display unit. For example, the embodiments of the present invention may be applied to image processing devices, such as a mobile phone, a navigation system, and a portable media player with an imaging function. 
         [0242]    The embodiment of the present invention illustrates one example for embodying the present invention, and the matters in the embodiment of the present invention and the specified matters of the invention in the claims have a correspondence relationship, as described in the embodiment of the present invention. Similarly, the specified matters of the invention in the claims and the matters in the embodiment of the present invention having the same names as the specified matters have a correspondence relationship. Here, the present invention is not limited to the embodiments, and various variations may be made to the embodiments without departing from the spirit and scope of the present invention. 
         [0243]    Further, the processing procedure described in the embodiments of the present invention may be regarded as a method including a series of procedures or as a program for causing a computer to execute a series of procedures or a recording medium having the program stored thereon. The recording medium may be, for example, a compact disc (CD), a mini disc (MD), a digital versatile disc (DVD), a memory card, or a Blu-ray disc (registered trademark). 
       REFERENCE SIGNS LIST 
       [0000]    
       
           100  Imaging device 
           101  Input/output panel 
           102  Shutter button 
           110  Input/output unit 
           111  Display unit 
           112  Manipulation receiving unit 
           120  Posture detection unit 
           130  Analysis unit 
           140  Control unit 
           150  Representative image reproduction unit 
           160  Group image reproduction unit 
           170  Rendering memory 
           180  Manipulation method determination unit 
           200  Image content storage unit 
           210  Image management information storage unit