Abstract:
A picture reproducer has a display, an image-selecting device, an offset-detecting device, and a memory. The display successively displays a plurality of images. The image-selecting device selects a first still image and a second still image from a plurality of images displayed on said display. The offset-detecting device detects the offset between the first still image and the second still image. The memory stores the offset. The offset-detecting device updates the offset stored in said memory every time the offset is detected. The display displays a target still image which is offset from another still image by the updated offset, when the another still image is selected.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a picture reproducer which may select desired images from successively displayed images. 
         [0003]    2. Description of the Related Art 
         [0004]    A conventional picture reproducer comprises a display which successively displays images and a selecting device which selects desired images from images continuously displayed on the display. A user selects desired images by operating the selecting device when he finds desired images during the observation of images displayed on the display. 
         [0005]    When images are updated at high frequencies, the user may fail to select a desired image due to his/her response lag in the selecting operation. It is disclosed in Japanese Unexamined Patent Publication (KOKAI) No. 2001-175281 that a conventional picture reproducer selects images in consideration of a user-specific delay time when a user executes the selecting operation such that a user may effectively select desired images. 
         [0006]    However, a conventional picture reproducer must measure delay time using test images before usage for each user. This is a cumbersome procedure for the user. A conventional picture reproducer must prepare test images and store them. Moreover, a conventional picture reproducer must measure the delay time again when a user intends to change the delay time. 
       SUMMARY OF THE INVENTION 
       [0007]    An object of the present invention is to provide a picture reproducer capable of selecting desired images from successively displayed images without performing any special procedure before usage. 
         [0008]    The present invention is a picture reproducer having a display, an image-selecting device, an offset-detecting device, and a memory. The display successively displays a plurality of images. The image-selecting device selects a first still image and a second still image from a plurality of images displayed on said display. The offset-detecting device detects the offset between the first still image and the second still image. The memory stores the offset. The offset-detecting device updates the offset stored in said memory every time the offset is detected. The display displays a target still image which is offset from another still image by the updated offset, when the another still image is selected. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings in which: 
           [0010]      FIG. 1  is a block diagram of a picture reproducer as the first embodiment of the present invention; 
           [0011]      FIG. 2  is a schematic view showing the display of a picture reproducer; 
           [0012]      FIG. 3  is a schematic view showing the display of a picture reproducer; 
           [0013]      FIG. 4  is a flowchart showing the identifying process; 
           [0014]      FIG. 5  is a flowchart showing the moving image stopping process; 
           [0015]      FIG. 6  is a schematic view showing the display of the picture reproducer in the second embodiment of the present invention; and 
           [0016]      FIG. 7  is a schematic view showing the display of the picture reproducer in the third embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    The first embodiment of the present invention is described below with reference to the drawings. 
         [0018]    The construction of the picture reproducer is described with reference to  FIGS. 1-3 . 
         [0019]    A picture reproducer  10  mainly comprises a control unit  11 , a display  12  which displays moving images, a memory  13  which stores moving images, a power switch  14  controls the power-on/power-off of the picture reproducer  10  and the operating devices  15 ,  16 , and  17  which input data to the control unit  11 . 
         [0020]    The operating devices  15 ,  16 , and  17  comprise a keyboard  15 , a mouse  16 , and a learning button  17 . The control unit  11  executes an identifying process as described later and identifies the user when the power of the picture reproducer  10  is turned on by operation of the power switch  14 . The control unit  11  reads moving images from the memory  13  and displays them. 
         [0021]    The display  12  comprises an image area  210  which displays moving images or a still image, an operating area  220  which displays operating buttons, and a scroll bar  230  which indicates the present reproduction position of the moving images. A play/pause button  221  which is used to start or pause the reproduction of the moving image, a stop button  222  which is used to stop the reproduction of the moving image, a first fast-forward button  223  which is used to fast-forward the moving image, a first fast-rewind button  224  which is used to fast-rewind moving image, a next track button  225  which displays the next moving image, and a previous track button  226  which displays the preceding moving image. A user may operate these buttons using the mouse  16 , in order to watch moving images. 
         [0022]    The scroll bar  230  comprises a progress bar  231  which indicates the complete reproduction time of a moving image, a slider  232  which indicates the current reproduction position of the moving image, and a second fast-forward button  233  and a second fast-rewind button  234  which are provided on the ends of the scroll bar  230 . A user may move the slider  232  by dragging the mouse  16 , and fast-forward or fast-rewind a moving image by clicking a second fast-forward button  233  and a second fast-rewind button  234  using the mouse  16 . 
         [0023]    The memory  13  may store a user data base which is constructed by associating user names with their individual time lags ΔTu. A time lag ΔT is the frame number from the moment that a user intends to stop a moving image to the moment that the reproduction of the moving image is actually stopped by operation of the play/pause button  221 . The control device  11  retrieves unique time lags ΔTu from the user database. 
         [0024]    The control device  11  temporarily stops reproducing a moving image by executing a moving image stopping process which is hereinafter described, when a user operates the play/pause button  221  during the reproduction of a moving image. For example, a moving image may be composed of 30 frames per second. A sequential series of fifteen frames are reduced in size and displayed on the display  12  as fifteen still images when the reproduction is stopped. For example, the offset of each image may be one frame. The fifteen still images are lined in ascending chronological order and connected by arrows in chronological order. The still image  211  centered in the series is not the still image of the frame which was being reproduced at the moment when the user operated the play/pause button  221  during the reproduction of the moving image, but the still image of the frame played with advance ΔT prior to the frame reproduced at the moment when the user actually operated the play/pause button  221 . This still image with offset ΔT is the first target image. Thereby, a user is more likely to be presented with the desired still image. 
         [0025]    The identifying process is described below with reference to  FIG. 4 . 
         [0026]    The control unit  11  executes the identifying process when the image reproducer  10  is powered on. At step S 41 , a login process is executed. In the login process, the display  12  displays a login screen which is used by a user to log in to the picture reproducer  10 . A user refers to the login screen and inputs his/her user name by keyboard  15  thereby logging into the picture reproducer  10 . A password may be required by the picture reproducer  10  to avoid abuse. 
         [0027]    In step S 42  it is judged whether an inputted user name is registered in the picture reproducer  10  or not. The judgment is executed by the control unit  11  which retrieves the inputted user name from a user database. The user database is stored in the memory  13 . In the case that a user name is not stored in the user database, the process proceeds to step S 43 . In the case that a user name is stored in the user database, a process goes to step S 44 . 
         [0028]    In step S 43 , the time lag ΔT is substituted by a mean time lag ΔTa which is calculated in advance and stored in the memory  13 . The mean time lag ΔTa is mean frame number which is the frame number of a moving image from the moment that an average user desires to stop the moving image to the moment that the moving image is actually stopped. 
         [0029]    In step S 44 , the time lag ΔT is substituted by the unique time lag ΔTu which is unique to the user who logs in to the picture reproducer  10  at the moment. The identifying process is exited after step S 43  and S 44  end. 
         [0030]    In the identification process, a user who has used the picture reproducer  10  before may use his/her unique time lag ΔTu without measuring the time lag ΔT again. 
         [0031]    The moving image stopping process is described with reference to  FIGS. 3-5 . The moving image stopping process is executed when a user operates the play/pause button  221 . 
         [0032]    In step S 51 , the control unit  11  displays a target image and fourteen still images which are created by reducing in size the fifteen still images of fifteen frames on the display  12 . The target image is a still image of the frame displayed at a time lag ΔT prior to the moment that the user operates the play/pause button  221  to stop the reproduction of a moving image while watching the moving image. The fourteen still images comprise seven still images of the seven frames which immediately precede the frame of the target image, and the other seven still images made from the seven frames which immediately follow the frame of the target image. 
         [0033]    This results in a greater chance of the target image being displayed for later selection, despite the user&#39;s delay in stopping the moving image. 
         [0034]    In step S 52 , it is judged whether the user has selected a desired image (second still image) from the fifteen displayed images or not. The selection is made by the user clicking the desired image on the display  12  using the mouse  16 . The user may therefore find a desired image even if his/her actual time lag differs from ΔT. 
         [0035]    In the case a desired still image is not selected in step S 52 , step S 52  is executed again. In the case it is selected, the process goes to step S 53 . 
         [0036]    In step S 53 , the selected still image is enlarged and displayed on the display  12  as illustrated in  FIG. 2 . This allows the user to observe the selected still image, i.e., the target image, in detail. 
         [0037]    In step S 54 , it is determined whether the control unit  11  learns the unique time lag ΔTu or not by determining whether the user has operated the learning button  17 . In the case the user has operated the learning button  17 , the process goes to step S 55 . In the case the user has not operated it, the moving image stopping process ends. 
         [0038]    In step S 55 , the control unit  11  calculates the number of frames between the frame selected by the user and the frame displayed at the moment of operating the play/pause button  221 , and inputs this frame number into the database as the user-specific time lag ΔTu. After that, the control unit  11  substitutes the time lag ΔT by the unique time lag ΔTu so that the time lag ΔT has been updated, i.e., learned. Then the moving image stopping process ends. 
         [0039]    According to the first embodiment, a user can observe a desired still image in detail even if the time lag ΔT differs from the actual time lag of a user. The unique time lag ΔTu may be input into the database when a user desires by operation of the learning button  17 . Moreover, the picture reproducer  10  can improve its accuracy in identifying the target image by this adjustment of the time lag ΔT. 
         [0040]    The second embodiment is described below with reference to  FIG. 6 . Descriptions of the constructions similar to the first embodiment are omitted. 
         [0041]    The control device  11  stops the reproduction of a moving image by executing a moving image stopping process when the user operates the play/pause button  221  during the reproduction of a moving image. The control unit  11  displays a second target image  212  and twenty still images which are created by reducing in size the twenty-one still images of twenty-one frames on the display  12 . The second target image  212  is a still image of the frame rewound by the time lag ΔT from the frame displayed at the moment that the user intended to operate the play/pause button  221 . In other words, the frame of the second target image  212  is offset by the time lag ΔT from the frame displayed at the moment that the user intended to operate the play/pause button  221 . The twenty still images comprise ten still images of the ten frames which immediately precede the frame of the second target image  212 , and the other ten still images of the ten frames which immediately follow the frame of the second target image  212 . The twenty-one still images are lined in ascending sequence of chronological order. The second target image  212  has a display area about four times larger than the other twenty still images, and is displayed in the center of the twenty-one still images. 
         [0042]    According to the second embodiment, a user may observe the desired still image, i.e., the target image, in detail. 
         [0043]    The third embodiment is described below with reference to  FIG. 7 . The descriptions of the constructions similar to the first and second embodiments are omitted. 
         [0044]    The control device  11  stops the reproduction of a moving image by executing a moving image stopping process, when the user operates the play/pause button  221  during the reproduction of a moving image. The control unit  11  displays a third target image  213 , a previous still image  214 , an subsequent still image  215 , and twelve still images which are created by reducing in size the fifteen still images of fifteen frames on the display  12 . The third target image  213  is a still image of the frame rewound by the time lag ΔT from the frame displayed at the moment that the user intended to operate the play/pause button  221 . In other words, the frame of the third target image  213  is offset by the time lag ΔT from the frame displayed at the moment that the user intended to operate the play/pause button  221 . The previous still image  214  is a still image of the frame which immediately precedes the frame of the third target image  213 . The subsequent still image  215  is a still image of the frame which immediately follows the frame of the third target image  213 . The twelve still images comprise the six still images made by reducing in size six images of the six frames which immediately precede the frame of the previous still image  214 , and the other 6 still images are made by reducing in size the six images of the six frames which immediately follow the frame of the subsequent still image  215 . 
         [0045]    The fifteen still images are ordered in ascending chronological order. The previous still image  214  and the subsequent still image  215  which immediately precede and follow the third target image  213 , and the third target image  213  are displayed in the center of the fifteen still images. The display areas of the third target image  213 , the previous still image  214 , and the subsequent still image  215  are the same. The display areas of the twelve still images are same. The display areas of the third target image  213 , the previous still image  214 , and the subsequent still image  215  are larger than the display areas of twelve still images. 
         [0046]    According to the third embodiment, a user may observe the desired still image, i.e. the target image and the still images which immediately precede and follow the target image in detail. 
         [0047]    Note that a user may select the user name from registered user names displayed on the display  12  by mouse  16  without inputting his/her user name in the login process. 
         [0048]    The still images may be displayed on the display  12  every plurality of frames, every second, or every plurality of seconds. 
         [0049]    The time lag ΔT and the unique time lag ΔT may be other than frame numbers, such as a time period from the moment that a user operates the play/pause button  221  to the moment reproduction of a moving image is stopped. The average time lag ΔT could also be other than a frame number, such as an average time period which is calculated by averaging the time periods from the moment that a user operates the play/pause button  221  to the moment the reproduction of a moving image is stopped. 
         [0050]    In step S 43  of the identifying process, the time lag ΔT may be substituted by 0, or an average of all of the unique time lags ΔTu stored in the user database. 
         [0051]    In step S 54  of the moving image stopping process, the dialog which is provided for asking users whether the picture reproducer  10  learns the unique time lag ΔTu or not may be displayed on the display  12 , and a user may be select whether learning or not by the keyboard  15  or the mouse  16 . 
         [0052]    In step S 55  of the moving image stopping process, the memory  13  may store the past unique time lags ΔTu; the new unique time lag ΔTu may be calculated by averaging the stored past unique time lags ΔTu and the present calculated unique time lag ΔTu. This improves the accuracy of the unique time lag ΔTu. 
         [0053]    The still images may be also be ordered in descending sequence of chronological order. 
         [0054]    The picture reproducer  10  in accordance with the present invention may display still images successively. A user can easily select the desired still images from the plurality of the still images. 
         [0055]    Although the embodiment of the present invention has been described herein with reference to the accompanying drawings, obviously many modifications and changes may be made by those skilled in the art without departing from the scope of the invention. 
         [0056]    The present disclosure relates to subject matter contained in Japanese Patent Application No. 2007-304383 (filed on Nov. 26, 2007), which is expressly incorporated herein, by reference, in its entirety.