Abstract:
When image data is sent and received between cameras via communication, it is possible for the user to ascertain the images that are being communicated. Thumbnail image data for transfer purposes is transmitted from a transmit-side camera to a receive-side camera. Main (full-size) image data is thenceforth transmitted from the transmit-side camera to the receive-side camera. When the main image data is sent and received, display screens on respective ones of the cameras display an image in which a transfer thumbnail image represented by transfer thumbnail image data moves from the display screen on the transmitting side to the display screen on the receiving side.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to a portable image communication system, a transmitting unit and a receiving unit that construct the system, and methods of controlling the transmitting and receiving units. 
         [0003]    2. Description of the Related Art 
         [0004]    There are occasions where image data is transmitted from one digital still camera to another. Such transmission makes it possible for image data obtained by photography using one digital still camera to be stored in the other digital still camera. In order to notify the user of the status of transmission of the image data, the user is informed of the number of images for which transmission has been completed (see the specification of Japanese Patent Application Laid-Open No. 2005-175794). 
         [0005]    Further, in a case where the image data is transmitted to an apparatus such as a computer, printer or facsimile machine, there are instances where an animation is displayed (see the specification of Japanese Patent Application Laid-Open No. 2000-137827). 
         [0006]    However, the user cannot determine what image is being transmitted. 
       SUMMARY OF THE INVENTION 
       [0007]    Accordingly, an object of the present invention is to so arrange it that the user can tell what image is being transmitted. 
         [0008]    The present invention provides a portable image communication system comprising a portable image transmitting unit and a portable image receiving unit. 
         [0009]    The portable image transmitting unit includes a thumbnail image data transmitting device (means) for transmitting thumbnail image data which represents a transfer thumbnail image corresponding to a main image, to the portable image receiving unit; and the portable image receiving unit includes a thumbnail image data receiving device (means) for receiving thumbnail image data that has been transmitted from the thumbnail image data transmitting device of the portable image transmitting unit; and a reception-end data transmitting device (means) for transmitting reception-end data to the portable image transmitting unit in response to end of reception of the thumbnail image data by the thumbnail image data receiving device. 
         [0010]    The portable image transmitting unit includes an end-data receiving device (means) for receiving reception-end data that has been transmitted from the reception-end data transmitting device; a main image data transmitting device (means) for transmitting main image data, which represents the main image, to the portable image receiving unit in response to reception of the reception-end data by the end-data receiving device; and a transmit-side display unit for displaying the transfer thumbnail image in such a manner that the transfer thumbnail image gradually disappears while it moves in one direction on a display screen in response to transmission of the main image data by the main image data transmitting-device. The portable image receiving unit further includes a main image data receiving device (means) for receiving-main image data that has been transmitted from the portable image transmitting unit; and a receive-side display unit for displaying the transfer thumbnail image in such a manner that the transfer thumbnail image gradually appears while it moves in one direction on a display screen in response to reception of the main image data by the main image data receiving device. 
         [0011]    The portable image transmitting unit and portable image receiving unit that construct the above-described portable image communication system may each stand-alone units. 
         [0012]    The present invention also provides a method of controlling the above-described portable image transmitting unit. Specifically, the method comprises the steps of: transmitting thumbnail image data, which represents a transfer thumbnail image corresponding to a main image, to a portable image receiving unit; receiving reception-end data that indicates end of transmission of the thumbnail image data that is transmitted from the portable image receiving unit in response to transmission of the thumbnail image data to the portable image receiving unit; transmitting main image data representing the main image to the portable image receiving unit in response to reception of the reception-end data; and displaying the transfer thumbnail image in such a manner that the transfer thumbnail image gradually disappears while moving in one direction on a display screen in response to transmission of the main image data. 
         [0013]    The present invention also provides a method of controlling the above-described portable image receiving unit. Specifically, the method comprises the steps of: receiving thumbnail image data representing a transfer thumbnail image corresponding to a main image that has been transmitted from a portable image transmitting unit; transmitting reception-end data to the portable image transmitting unit in response to end of reception of the thumbnail image data; receiving main image data, which is transmitted from the portable image transmitting unit, in response to transmission of the reception-end data to the portable image transmitting unit; and displaying the transfer thumbnail image in such a manner that the transfer thumbnail image gradually appears while moving in one direction on a display screen in response to reception of the main image data. 
         [0014]    In accordance with the present invention, thumbnail image data representing a transfer thumbnail image corresponding to a main image is transmitted from the portable image transmitting unit to the portable image receiving unit. The thumbnail image data is received by the portable image receiving unit. When reception ends, reception-end data is transmitted from the portable image receiving unit to the portable image transmitting unit. When the reception-end data is received by the portable image transmitting unit, main image data corresponding to the thumbnail image data already transmitted is transmitted from the portable image transmitting unit to the portable image receiving unit, and the transfer thumbnail image is displayed on the display screen of a transmit-side display unit of the image transmitting unit in such a manner that the transfer thumbnail image gradually disappears while it moves in one direction on the display screen. When the main image data that has been transmitted from the image transmitting unit is received by the image receiving unit, the transfer thumbnail image is displayed on the display screen of a receive-side display unit in such a manner that the transfer thumbnail image gradually appears while it moves in one direction on the display screen. 
         [0015]    Since a transfer thumbnail image corresponding to main image data that is being transmitted from the image transmitting unit to the image receiving unit is displayed just as if it were being moved from the image transmitting unit to the image receiving unit, the user can tell at a glance what image is represented by the main image data that is being transmitted from the image display unit to the image receiving unit (received by the image receiving unit from the image transmitting unit). Further, by observing the manner in which the transfer thumbnail image is moving, it can be confirmed that transmission (reception) of the main image data is in progress. Furthermore, since the transmission of the thumbnail image data ends before the transmission of the main image, main image data that has not been received can be found by comparing the main image data and the thumbnail image data in the image receiving unit. 
         [0016]    By way of example, in the portable image transmitting unit, the thumbnail image data transmitting device and the main image data transmitting device are a wireless communication device provided on an end face of the portable image transmitting unit. In this case, the display unit on the transmit side would display the transfer thumbnail image in such a manner that the thumbnail image gradually disappears while it moves on the display screen toward the side on which the wireless communication device has been provided, in response to transmission of the main image data by the main image data transmitting device. 
         [0017]    In this case, in the portable image receiving unit, the thumbnail image data receiving device and the main image data receiving device would also be a wireless communication device provided on an end face of the portable image receiving unit. The display unit on the receive side would display the transfer thumbnail image in such a manner that the thumbnail image gradually appears while it moves on the display screen toward the side opposite the side on which the wireless communication device is provided, in response to reception of the main image data by the main image data receiving device. 
         [0018]    The portable image transmitting unit may further include a display control device (means) for controlling the transmit-side display unit in such a manner that images obtained by turning transfer thumbnail images upside-down are displayed in a gradually stacked manner while moving on the display screen toward the side on which the wireless communication device has been provided, in response to transmission of the transfer thumbnail image data by the thumbnail image data transmitting device. 
         [0019]    Further, the transmit-side display unit may display the transfer thumbnail image in such a manner that the transfer thumbnail image data moves on the display screen toward the side on which the wireless display device has been provided while it is rotated clockwise by 90° from an upright attitude, and gradually disappears before or after rotation ends, in response to transmission of the main image data by the main image data transmitting device. 
         [0020]    In this case, the receive-side display unit of the portable image receiving unit displays the transfer thumbnail image in such a manner that the transfer thumbnail image, which has been rotated clockwise by 90° from an upright attitude, gradually appears while moving on the display screen toward the side opposite the side on which the wireless communication device has been provided, and displays the transfer thumbnail image in the upright attitude while rotating the thumbnail image clockwise by a further 90° before one frame of the transfer thumbnail image appears completely or after it has appeared completely, in response to reception of the main image data by the main image data receiving device. 
         [0021]    The transmit-side display unit of the portable image transmitting unit may subject the transfer thumbnail image to the rotation processing after movement thereof starts. 
         [0022]    In this case, the receive-side display unit of the portable image receiving unit may move the transfer thumbnail image toward the side opposite the side on which the wireless communication device has been provided after rotation of the transfer thumbnail image clockwise by 90° has been completed. 
         [0023]    The receive-side display unit of the portable image receiving unit may display an image, which has been obtained by turning the transfer thumbnail image upside down, in such a manner that the image gradually appears while it moves on the display screen toward the side opposite the side on which the wireless communication device has been provided, in response to reception of the main image data by the main image data transmitting device. 
         [0024]    The transmit-side display unit of the portable image transmitting unit may display the transfer thumbnail image in such a manner that the transfer thumbnail image disappears while it is gradually reduced in size and moving on the display screen toward the side on which the wireless communication device has been provided, in response to transmission of the main image data by the main image data transmitting device. 
         [0025]    In this case, the receive-side display unit of the portable image receiving unit preferably displays the transfer thumbnail image in such a manner that the transfer thumbnail image appears while it is gradually increased in size and moving on the display screen, in response to reception of the main image data by the main image data receiving device. 
         [0026]    The portable image transmitting unit may further include a display control device (means) for controlling the display unit in such a manner that the transfer thumbnail image is displayed in a stacked manner while being rotated from an upright state to an inverted state while moving on the display screen toward the side on which the wireless communication device has been provided, in response to transmission of the thumbnail image data by the thumbnail image data transmitting device. 
         [0027]    The portable image transmitting unit may further include a display control device (means) for controlling the display unit in such a manner that the transfer thumbnail image is displayed in a stacked manner while being rotated clockwise by 90° from an upright attitude, in response to transmission of the thumbnail image data by the thumbnail image data transmitting device. 
         [0028]    Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]      FIG. 1  is a back view of a digital still camera; 
           [0030]      FIG. 2  is a block diagram illustrating the electrical structure of the digital still camera; 
           [0031]      FIG. 3  illustrates the manner in which image data is sent and received; 
           [0032]      FIG. 4  is a flowchart illustrating part of processing executed by a camera on the transmit side; 
           [0033]      FIG. 5  is a flowchart illustrating part of processing executed by the camera on the transmit side; 
           [0034]      FIG. 6  is a flowchart illustrating part of processing executed by a camera on the receive side; 
           [0035]      FIG. 7  is a flowchart illustrating part of processing executed by the camera on the receive side; 
           [0036]      FIG. 8  illustrates the manner in which image data is sent and received; 
           [0037]      FIGS. 9A and 9B  illustrate the manner in which image data is sent and received; 
           [0038]      FIGS. 10A and 10C  illustrate the manner in which image data is sent and received,  FIG. 10B  illustrates an example of a display screen on the transmit side, and  FIG. 10D  illustrates an example of a display screen on the receive side; 
           [0039]      FIGS. 11A and 11B  illustrate the manner in which image data is sent and received, and  FIG. 11C  illustrates examples of display screens on the transmit and receive sides, respectively; 
           [0040]      FIG. 12A  illustrates the manner in which image data is sent and received, and  FIG. 12B  illustrates examples of display screens on the transmit and receive sides, respectively; 
           [0041]      FIG. 13A  illustrates the manner in which image data is sent and received, and  FIG. 13B  illustrates examples of display screens on the transmit and receive sides, respectively; 
           [0042]      FIG. 14  illustrates the manner in which image data is sent and received; and 
           [0043]      FIGS. 15A and 15C  illustrate the manner in which image data is sent and received,  FIG. 15B  illustrates an example of a display screen on the transmit side, and  FIG. 15D  illustrates an example of a display screen on the receive side; 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0044]    Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 
         [0045]      FIG. 1  is a back view of a digital still camera  1  according to an embodiment of the present invention. 
         [0046]    The digital still camera  1  according to this embodiment is capable of sending and receiving image data. 
         [0047]    A shutter-release button  2  is provided at the right side of the upper surface of the digital still camera  1 . 
         [0048]    The back side of the digital still camera  1  is formed to have a liquid crystal display screen  7  substantially over the entirety thereof. Provided at the upper right of the display screen  7  is a so-called cross-hair key  3  on which up, down, left and right arrows are formed in such a manner that they can be pressed. Provided below the cross-hair key  3  are a decision button  4  pressed by the user when image data to be transmitted is decided, and a transmit button  5  for starting the transmission of image data. A mode setting dial  6  is provided below the decision button  4  and transmit button  5 . Modes that can be set by the mode setting dial  6  include an image sensing mode, a playback mode, a transmit mode and a receive mode. 
         [0049]    An input/output portion  8  of communication unit for sending and receiving image data is formed on the left side face (the left side face as seen from the back side) of the digital still camera  1 . 
         [0050]      FIG. 2  is a block diagram illustrating the electrical structure of the digital still camera  1 . 
         [0051]    The operation of the overall digital still camera  1  is controlled by a CPU  10 . 
         [0052]    The digital still camera  1  includes an operating unit  12  having a variety of buttons such as the shutter-release button  2 . Output signals from the operating unit  12  are input to the CPU  10 . 
         [0053]    If the image sensing mode is set, main (i.e., full-size) image data representing the image of a subject sensed by an image sensing unit  11  is input to an image processing unit  13  via the CPU  10 . By subjecting the image data to prescribed image processing in the image processing unit  13  and applying the processed image data to a display unit  15 , the image of the subject is displayed on the display screen of the display unit  15 . If the shutter-release button  2  is pressed, the main image data thus obtained is applied to and stored in a storage unit  14 . 
         [0054]    The image processing unit  13  also executes processing (memory mapping processing for display) for displaying an image, such processing including processing for moving and rotating a thumbnail image that is for transfer purposes (such thumbnail image data will also be referred to as “transfer thumbnail image data” below), as will be described later. 
         [0055]    If the transmit mode is set, transfer thumbnail image data representing an image that has been selected by the user is transmitted from an infrared communication unit  16  to a digital still camera on a receiving side. After the transfer thumbnail image data is transmitted, main image data, which corresponds to the above-mentioned transfer thumbnail image data, is transmitted from the infrared communication unit  16  to the digital still camera on the receiving side. While the transmission of the main image data is in progress, the transfer thumbnail image represented by the transfer thumbnail image data corresponding to this main image data is displayed on the display screen of the display unit  15  while it is moved just as if it were being sent to the digital still camera on the receiving side. By observing the transfer thumbnail image being displayed, the user can tell that processing for transmitting the main image data is in progress and can confirm what subject image is represented by the image data that is being transmitted. The amount of transfer thumbnail image data is decided in accordance with the transmission speed of the infrared communication unit  16  and the display speed of the display unit  15 . Generally, the amount of transfer thumbnail image data is less than the amount of main image data. Further, the transfer thumbnail image data may be generated when the main image data is stored in the storage unit  14 , or may be generated after the transmit mode is set and the image to be transmitted decided. 
         [0056]    The digital still camera on the receiving side is set to the receive mode. Transfer thumbnail image data that has been transmitted from the digital still camera  1  on the transmitting side is stored in the digital still camera on the receiving side. When reception of main image data starts, a transfer thumbnail image represented by transfer thumbnail image data corresponding to the main image data being received is displayed while being moved on the display screen of the display unit on the receiving side. By observing the transfer thumbnail image being displayed, the user also of the digital still camera on the receiving side can tell that processing for receiving the image data is in progress and can confirm what subject image is represented by the image data that is being received. It goes without saying that the amount of transfer thumbnail image data is decided taking into consideration the reception speed of the infrared communication unit  16  and the display speed of the display unit  15  of the digital still camera on the receiving side. 
         [0057]      FIG. 3  illustrates the situation when image data is being sent and received using a transmit-side digital still camera and a receive-side digital still camera. 
         [0058]    A transmit-side user  61 A holds a transmit-side digital still camera  1 A in his/her right hand, and a receive-side user  61 B holds a receive-side digital still camera  1 B in his/her right hand. The reference characters of the portions constituting the transmit-side digital still camera  1 A and receive-side digital still camera  1 B are obtained by appending A and B to the reference characters of the portions described above in conjunction with  FIG. 1 . These portions need not be described again. 
         [0059]    The transmit-side digital still camera  1 A is held by the transmit-side user  61 A and the receive-side digital still camera  1 B is held by the receive-side user  61 B in such a manner that the input/output portion  8 A of the communication unit of the transmit-side digital still camera  1 A and the input/output portion  8 B of the communication unit of the transmit-side digital still camera  1 B will point toward each other. 
         [0060]    When main image data is sent and received, an image  9  is displayed on display screen  7 A of the transmit-side digital still camera  1 A and on display screen  7 B of the receive-side digital still camera  1 B so as to move from the transmit-side digital still camera  1 A to the receive-side digital still camera  1 B in the manner described above. 
         [0061]      FIGS. 4 to 7  are flowcharts illustrating processing executed when main image data is transmitted from the transmit-side digital still camera  1 A (referred to as “transmit-side camera  1 A” below) to the receive-side digital still camera  1 B (referred to as “receive-side camera  1 B” below).  FIGS. 4 and 5  are flowcharts illustrating processing executed by the transmit-side camera  1 A, and  FIGS. 6 and 7  are flowcharts illustrating processing executed by the transmit-side camera  1 B. 
         [0062]    The transmit-side camera  1 A is set to the transmit mode (step  21  in  FIG. 4 ). When this is done, thumbnail images represented by image data that has been stored is displayed as a list on the display screen  7 A on the transmitting side. A thumbnail image corresponding to image data to be transmitted to the receive-side camera  1 B is selected from among the thumbnail images displayed (step  22  in  FIG. 4 ). Next, the input/output portion  8 A of the communication unit is pointed toward the receive-side camera  1 B by the user of the transmit-side camera  1 A (step  23  in  FIG. 4 ). 
         [0063]    The receive-side camera  1 B is set to the receive mode (step  41  in  FIG. 6 ). The input/output portion  8 B of the communication unit is pointed toward the transmit-side camera  1 A by the user of the receive-side camera  1 B (step  42  in  FIG. 6 ). 
         [0064]    As illustrated in  FIG. 3 , the input/output portion  8 A of the communication unit of transmit-side camera  1 A and the input/output portion  8 B of the communication unit of receive-side camera  1 B are pointed toward each other. 
         [0065]    If the transmit button  5 A of transmit-side camera  1 A is pressed (“YES” at step  24  in  FIG. 4 ), a communication request is transmitted from transmit-side camera  1 A to receive-side camera  1 B (step  25  in  FIG. 4 ). When the receive-side camera  1 B receives the communication request (“YES” at step  43  in  FIG. 6 ), a communication response is transmitted from the receive-side camera  1 B to the transmit-side camera  1 A (step  44  in  FIG. 6 ). 
         [0066]    When the communication response that has been transmitted from the receive-side camera  1 B is received by the transmit-side camera  1 A (“YES” at step  26  in FIG.  4 ), transfer thumbnail image data corresponding to the selected image is transmitted from the transmit-side camera  1 A to the receive-side camera  1 B (step  27  in  FIG. 5 ). If communication is severed (“YES” at step  29  in  FIG. 5 ) before end of transmission of all of the transfer thumbnail image data that corresponds to all of the images selected (“NO” at step  28  in  FIG. 5 ), then prescribed error processing is executed. 
         [0067]    The transfer thumbnail image data that has been transmitted from the transmit-side camera  1 A is received by the receive-side camera  1 B (step  45  in  FIG. 7 ). If communication ends (“YES” at step  47  in  FIG. 7 ) before all of the transfer thumbnail image data transmitted from the transmit-side camera  1 A is received (“NO” at step  46  in  FIG. 7 ), then prescribed error processing is executed. If all of the transfer thumbnail image data that is transmitted from the transmit-side camera  1 A is received by the receive-side camera  1 B (“YES” at step  46  in  FIG. 7 ), then data indicating end of reception is transmitted from the receive-side camera  1 B to the transmit-side camera  1 A (step  48  in  FIG. 7 ). 
         [0068]    When the data indicative of end of reception transmitted from the receive-side camera  1 B is received by the transmit-side camera  1 A (“YES” at step  30  in FIG.  5 ), main image data corresponding to the transfer thumbnail image data that has been transmitted is read out of the storage unit and transmitted to the receive-side camera  1 B (step  31  in  FIG. 5 ). While transmission of the main image data is in progress, the transfer thumbnail image represented by the transfer thumbnail image data corresponding to the main data being transmitted is displayed on the display screen of the transmit-side camera  1 A so as to move toward receive-side camera  1 B (step  32  in  FIG. 5 ) in the manner described above. 
         [0069]    The main image data that has been transmitted from the transmit-side camera  1 A is received by the receive-side camera  1 B (step  49  in  FIG. 7 ). While reception of the main image data is in progress, the transfer thumbnail image data corresponding to the main image data being received is displayed on the display screen of the receive-side camera  1 B so as to move from the transmit-side camera  1 A (step  50  in  FIG. 7 ). 
         [0070]    If communication is severed (“YES” at step  34  in  FIG. 5 ) at the transmit-side camera  1 A before transmission of all of the main image data ends (“NO” at step  33 ), the prescribed error processing is executed. Transmission of the main image data and display of the transfer thumbnail image data are carried out until the transmission of all of the main image data ends (steps  31 ,  32  in  FIG. 5 ). 
         [0071]    If communication is severed (“YES” at step  52  in  FIG. 7 ) at the receive-side camera  1 B before the reception of all of the main image data ends (“NO” at step  51 ), then prescribed error processing is executed. Reception of the main image data and display of the transfer thumbnail image data are carried out until the reception of all of the main image data ends (steps  49 ,  50  in  FIG. 7 ). 
         [0072]      FIG. 8  illustrates the manner, as seen from above, in which the transmit-side user  61 A holds the transmit-side camera  1 A, the receive-side user  61 B holds the receive-side camera  1 B and image data is sent and received. 
         [0073]    In a case where the input/output portion of the communication unit of transmit-side camera  1 A and the input/output portion of the communication unit of transmit-side camera  1 B are pointed toward each other, the up-down direction of the transmit-side camera  1 A and the up-down direction of the receive-side camera  1 B become the opposite of each other. (The side on which the shutter-release button is provided is the top side of the camera. Refer also to  FIG. 3 .) Consequently, unless a transfer thumbnail image displayed on the transmit-side camera  1 A and a transfer thumbnail image displayed on the receive-side camera  1 B are displayed in an upside-down relationship with respect to each other, and unless the lateral directions of movement of the images are made the opposite of each other (i.e., unless the image is made to approach the input/output portion  8 A of transmit-side camera  1 A and to move away from the input/output portion  8 B of receive-side camera  1 B), the image will not appear to move from the transmit-side camera  1 A to the receive-side camera  1 B. 
         [0074]      FIGS. 9A to 15D  illustrate how a transfer thumbnail image is displayed. Portions in these Figures that are identical with those shown in  FIG. 3  are designated by like reference characters and need not be described again. Further, although a transfer thumbnail image is being displayed on the display screen  7 A of transmit-side camera  1 A not only when main image data is being sent and received but also when transfer thumbnail image data is being sent and received, the transfer thumbnail image need not necessarily be displayed when transfer thumbnail image data is sent and received. It goes without saying that these displays of images can be implemented by mapping the transfer thumbnail image data to memory, as mentioned above. 
         [0075]      FIG. 9A  illustrates the situation when transfer thumbnail image data is sent and received. 
         [0076]    A transfer thumbnail image  71 A that has been turned upside-down is displayed on the display screen  7 A on the transmitting side. In a case where the user has selected a plurality of frames of the transfer thumbnail image data, the upside-down transfer thumbnail images  71 A are displayed in a form in which they are stacked. Users  61 A and  16 B can ascertain that preparations for transmitting the main image data are being made by observing the transfer thumbnail images  71 A. 
         [0077]    When transfer thumbnail image data is sent and received, main image data will not yet have been received by the receive-side camera  1 B. Accordingly, text reading “RECEPTION SET-UP IN PROGRESS” is displayed instead of a transfer thumbnail image on the receive-side camera  1 B. 
         [0078]      FIG. 9B  illustrates the situation when main image data is sent and received. 
         [0079]    An image in which the transfer thumbnail images  71 A that were stacked at the sending and receiving of the transfer thumbnail image data are moved one frame at a time toward the side of the input/output portion  8 A is displayed on the transmit-side display screen  7 A. 
         [0080]    An image in which transfer thumbnail images  71 B move away from the side of the input/output portion  8 B one frame at a time is displayed on the receive-side display screen  7 B. 
         [0081]    Since the transfer thumbnail image  71 A that has been turned upside-down is displayed on the transmit-side display screen  7 A, movement seems natural and it appears just as if the image per se is moving from the transmit-side camera  1 A to the receive-side camera  1 B. 
         [0082]      FIGS. 10A to 10D  illustrate another modification. Portions in these Figures that are identical with those shown in  FIG. 3  are designated by like reference characters and need not be described again. 
         [0083]      FIG. 10A  illustrates the situation when transfer thumbnail image data is sent and received. 
         [0084]    Displayed on the transmit-side display screen  7 A is an image in which transfer thumbnail images  72 A are stacked by being rotated clockwise by 90° from the upright attitude. Text reading “RECEPTION SET-UP IN PROGRESS” is displayed on the receive-side display screen  7 B. 
         [0085]      FIG. 10B  illustrates the transmit-side display screen  7 A shown in  FIG. 10A . 
         [0086]    A transfer thumbnail image  73 A prior to rotation is in an upright attitude in which the up direction of the transmit-side camera  1 A is the up direction of the image. By moving the transfer thumbnail image  73 A to the input/output portion  8 A while the image is being rotated, a transfer thumbnail image  74 A that has been rotated 90° from the upright attitude is obtained. However, the 90° clockwise rotation ends before the transfer thumbnail image  74 A contacts the right side of the display screen  7 A. The transfer thumbnail image  74 A thus rotated moves to the right side of the display screen  7 A subsequently. As described above, the transfer thumbnail image  74 A is stacked when the transfer thumbnail image data is transmitted. 
         [0087]      FIG. 10C  illustrates the situation when main image data is sent and received. 
         [0088]    The transfer thumbnail images  72 A are displayed on the transmit-side display screen  7 A in stacked form in the manner described above. An image in which the stacked transfer thumbnail images  72 A are moved one frame at a time toward the side of the input/output portion  8 A is displayed. 
         [0089]    Displayed on the receive-side display screen  7 B is an image in which the vertically oriented transfer thumbnail images  72 B become upright while being rotated clockwise by 90°. 
         [0090]      FIG. 10D  illustrates the receive-side display screen  7 B shown in  FIG. 10C . 
         [0091]    A transfer thumbnail image  73 B situated on the left side of the display screen  7 B (the side on which the input/output portion  8 B is located) is being, displayed in the vertical orientation in the manner described above. After the image is moved in this vertically orientated state, it is moved away from the input/output portion  8 B while being rotated clockwise by 90°, whereby an upright transfer thumbnail image  74 B is obtained. 
         [0092]      FIGS. 11A to 11C  illustrate a further modification. 
         [0093]      FIG. 11A  illustrates the situation when transfer thumbnail image data is sent and received. 
         [0094]    When transfer thumbnail image data is sent and received, an image in which transfer thumbnail images  75 A are stacked one upon another is displayed on the transmit-side display screen  7 A. Text reading “RECEPTION SET-UP IN PROGRESS” is displayed on the receive-side display screen  7 B. 
         [0095]      FIG. 11B  illustrates the situation when main image data is sent and received. 
         [0096]    When main image data is sent and received, the transfer thumbnail image  75 A is displayed on the transmit-side display screen  7 A while being rotated clockwise by 90° from the upright state. A transfer thumbnail image  75 B is displayed on the receive-side display screen  7 B while being rotated clockwise by 90° from the vertical state to the upright state. 
         [0097]      FIG. 11C  illustrates the transmit-side display screen  7 A and the receive-side display screen  7 B. 
         [0098]    As mentioned above, an upright transfer thumbnail image  76 A is displayed on the transmit-side display screen  7 A and a transfer thumbnail image  77 A that has been rotated clockwise by 90° is displayed on the transmit-side display screen  7 A. A vertical transfer thumbnail image  76 B is displayed on the receive-side display screen  7 B. By rotating this transfer thumbnail image  76 B clockwise by a further 90°, a transfer thumbnail image  77 B in the upright state is obtained. 
         [0099]      FIGS. 12A and 12B  illustrate another modification. In this modification, the situation when transfer thumbnail image data is sent and received is the same as that shown in  FIG. 11A . 
         [0100]      FIG. 12A  illustrates the situation when main image data is sent and received. 
         [0101]    Displayed on the transmit-side display screen  7 A and receive-side display screen  7 B are images in which transfer thumbnail images  78 A and  78 B are moved from the transmit-side camera  1 A to the receive-side camera  1 B while being rotated. 
         [0102]      FIG. 12B  illustrates the transmit-side display screen  7 A and the receive-side display screen  7 B. 
         [0103]    On the transmit-side display screen  7 A, transfer thumbnail images  79 A,  80 A in the upright state are rotated clockwise by 90° to obtain a transfer thumbnail image  81 A. The transfer thumbnail image  81 A thus rotated by 90° is not moved laterally in the 90°-rotated state but becomes a vertically orientated transfer thumbnail image  79 B on the receive-side display screen  7 B. Transfer thumbnail images  80 B,  81 B that have been rotated by a further 90° are displayed on the receive-side display screen  7 B. 
         [0104]      FIGS. 13A and 13B  illustrate a further modification. In this modification, the situation when transfer thumbnail image data is sent and received is the same as that shown in  FIG. 11A . 
         [0105]      FIG. 13A  illustrates the situation when main image data is sent and received. 
         [0106]    A state in which transfer thumbnail images  82 A in the upright attitude are being moved toward the input/output portion  8 A one frame at a time is displayed on the transmit-side display screen  7 A. A state in which transfer thumbnail images  82 B in the upright attitude are being moved away from the input/output portion  8 B one frame at a time is displayed on the receive-side display screen  7 B. 
         [0107]      FIG. 13B  illustrates the transmit-side display screen  7 A and the receive-side display screen  7 B. 
         [0108]    As mentioned above, a transfer thumbnail image  83 A is moved in the upright attitude toward the input/output portion  8 A on the transmit-side display screen  7 A. A transfer thumbnail image  83 B is moved in the upright state on the receive-side display screen  7 B. 
         [0109]      FIG. 14  illustrates a further modification and shows the situation when main image data is sent and received. The situation when transfer thumbnail image data is sent and received is the same as that shown in  FIG. 11A . 
         [0110]    Displayed on the transmit-side display screen  7 A is an image in which transfer thumbnail images  84 A in the upright state become gradually smaller while being moved toward the input/output portion  8 A. Displayed on the receive-side display screen  7 B are transfer thumbnail images  84 B in which the transfer thumbnail images that become gradually smaller on the transmit-side display screen  7 A move away from the input/output portion  8 B while becoming gradually larger. It goes without saying that this size-reduction processing also is executed in the image processing unit  13 . 
         [0111]      FIGS. 15A to 15D  illustrate a further embodiment. 
         [0112]      FIG. 15A  illustrates the situation when transfer thumbnail image data is sent and received. 
         [0113]    Displayed on the transmit-side display screen  7 A is an image in which transfer thumbnail images  85 A in the upright state are rotated clockwise (or counter-clockwise) by 180° (i.e., in which the images  85 A are turned upside-down). The wording “RECEPTION SET-UP IN PROGRESS” is displayed on the receive-side display screen  7 B. Transfer thumbnail images  85 A that have been turned upside-down are stacked. 
         [0114]      FIG. 15B  illustrates the transmit-side display screen  7 A. 
         [0115]    A transfer thumbnail image  86 A is in the upright state. By rotating the upright transfer thumbnail image  86 A clockwise or counter-clockwise by 180°, a transfer thumbnail image  87 A that has been turned upside-down is displayed on the transmit-side display screen  7 A. 
         [0116]      FIG. 15C  illustrates the situation when main image data is sent and received. 
         [0117]    Displayed on the transmit-side display screen  7 A is an image in which transfer thumbnail images  85 A that have been turned upside-down move one frame at a time toward the input/output portion  8 A. Displayed on the receive-side display screen  7 B is an image in which transfer thumbnail images  85 B in the upright state move laterally away from the input/output portion  8 B one frame at a time. 
         [0118]      FIG. 15D  illustrates an example of the receive-side display screen  7 B. 
         [0119]    As mentioned above, a transfer thumbnail image  86 B is upright, and the upright transfer thumbnail image  86 B moves so as to depart from the input/output portion  8 B (to become a transfer thumbnail image  87 B). 
         [0120]    In the foregoing embodiment, image data is sent and received using a digital still camera. However, it may be so arranged that image data is sent and received using another portable device. Further, although image data is sent and received using infrared communication in the foregoing embodiments, image data may be sent and received using wired communication. 
         [0121]    As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.