Abstract:
An image processing apparatus for inputting a moving image file containing moving image data representing a series of moving images, and still image data of a plurality of pictures related to the moving image data, selecting representative still image data from the still image data of the plurality of pictures of the inputted moving image file, recording identification information for identifying the selected representative still image data in the moving image file.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to an image processing apparatus and, more particularly, to processing of a representative picture of a moving image file.  
           [0003]    2. Related Background Art  
           [0004]    Recently, a camera-integrated digital disk recorder has been proposed for recording photographed moving image data as a moving image file. Also, a digital camera has been proposed for recording photographed moving image data as a moving image file in a solid memory such as a memory card.  
           [0005]    In such apparatus, a user selects and reproduces a target moving image file from a plurality of recorded moving image files by verifying a thumbnail (index) image corresponding to each moving image file.  
           [0006]    The thumbnail image is a still image, in which a representative picture corresponding to each moving image file is reduced from a normal size, and it has been suggested to use one frame being at a head of each moving image data as a representative picture.  
           [0007]    However, depending on a content to be photographed, a head frame of each moving image data does not always represent the moving image data. If such a head frame is used as a thumbnail, it may be difficult for the user to search the target moving image file.  
           [0008]    For example, if photographing is started in a fading-in manner from a black picture screen, a thumbnail prepared from the head frame is displayed on a totally black picture and, consequently, a content of the moving image frame cannot be determined from this thumbnail.  
           [0009]    In order to avoid the above-described problem, instead of the head frame, one frame positioned after a passage of a given period from the head may be employed as a thumbnail image.  
           [0010]    Such a case is effective when photographing is started in the fading-in manner from the black picture screen. However, data of a moving image photographed by the user contains a variety of contents, and thus the above-described case is not effective for all of the contents.  
           [0011]    Especially, to make use of features of a digital disk camera or a digital camera capable of randomly designating and reproducing a plurality of recorded moving image files, it is important to provide a method of more easily forming a thumbnail image to the user so that the user can easily understand contents of the thumbnail image intuitively when selecting a target moving image file.  
         SUMMARY OF THE INVENTION  
         [0012]    An object of the present invention is to solve the foregoing problems.  
           [0013]    Another object of the present invention is to set a representative picture representing a content of moving image data well by a simple operation.  
           [0014]    In order to attain the above-described object, in accordance with an aspect of the invention, there is provided an image processing apparatus comprising: inputting means for inputting a moving image file containing moving image data representing a series of moving images, and still image data of a plurality of pictures related to the moving image data; selecting means for selecting representative still image data from the still image data of the plurality of pictures of the moving image file inputted by the inputting means; and recording means for recording identification information for identifying the selected representative still image data in the moving image file.  
           [0015]    These and other objects, and features of the present invention will become apparent upon reading of detailed description of the embodiments with reference to the accompanying drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a block diagram showing a configuration of a camera recorder, to which the present invention is applied.  
         [0017]    [0017]FIG. 2 is a view showing a structure of a moving image file processed in an embodiment of the invention.  
         [0018]    [0018]FIG. 3 is a view showing a display picture screen of a thumbnail image in the embodiment of the invention.  
         [0019]    [0019]FIG. 4 is a view showing a set picture screen of the thumbnail image in the embodiment of the invention.  
         [0020]    [0020]FIG. 5 is a flowchart showing a thumbnail setting operation.  
         [0021]    [0021]FIG. 6 is a view showing a configuration of a personal computer system, to which the invention is applied.  
         [0022]    [0022]FIG. 7 is a view showing a situation of program modules in the computer system of FIG. 6.  
         [0023]    [0023]FIG. 8 is a view showing a configuration of a system, to which the invention is applied.  
         [0024]    [0024]FIG. 9 is a view showing a configuration of a camera, to which the invention is applied.  
         [0025]    [0025]FIG. 10 is a view showing a configuration of a system, to which the invention is applied.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]    Hereinafter, description will be made of the preferred embodiments of the present invention.  
         [0027]    First, description is made of a first embodiment of the invention.  
         [0028]    [0028]FIG. 1 is a block diagram showing a configuration of a digital disk camera recorder (referred to as camcorder hereinafter)  100 , to which the invention is applied.  
         [0029]    In FIG. 1, a reference numeral  101  denotes an image pickup unit, which uses a CCD as an image pickup element;  102  a camera signal processing unit;  103  a display unit, a liquid crystal panel being used as such in the embodiment;  104  an MPEG circuit for encoding/decoding moving image data;  105  a JPEG circuit for encoding/decoding still image data; and  106  a network I/F circuit for transferring data according to serial bus I/F Standard of IEEE1394 in the embodiment.  
         [0030]    A reference numeral  107  denotes a format unit;  108  a work memory of the format unit  107 ; and  109  a recording and reproducing unit including a laser pickup, a magnetic head and other well-known elements in the embodiment. A reference code D denotes a magneto-optical disk. A reference numeral  110  denotes a servo circuit including a spindle motor and the like for rotary-driving the camcorder  100 ;  111  a system control unit which controls each element of the camcorder  100 ;  112  a key operation unit;  113  an audio video (AV) I/O unit;  114  a base band data bus;  115  an encoded data bus; and  116  a network terminal.  
         [0031]    Next, description is made of a basic flow of a recording operation of the camcorder  100  of FIG. 1.  
         [0032]    Moving image data obtained by the image pickup unit  101  is subjected to signal-processing at the camera signal processing unit  102 , and then outputted through the data bus  114  to the MPEG circuit  104  and the JPEG circuit  105 . The MPEG circuit  104  encodes the moving image data outputted from the camera signal processing unit  102  in a format conformed to MPEG 2, and outputted through the data bus  115  to the format unit  107 . For the moving image data outputted from the MPEG circuit  104 , the format unit  107  executes packetizing according to a recording format of a disk D or encoding for a disk file system, and outputs the processed data to the recording and reproducing unit  109 . The recording and reproducing unit  109  records the data outputted from the format unit  107  as a moving image file in the disk D by using a well-known laser pickup or magnetic disk.  
         [0033]    On the other hand, the JPEG circuit  105  extracts image data of one frame from the moving image data supplied through the data bus  114  from the camera signal processing unit  102  at every fixed period, reduces its size, and encoding the extracted image data according to JPEG Standard, thus generating candidate data of a thumbnail image. Here, the thumbnail candidate data regards a candidate of a thumbnail image possibly used as a thumbnail to characterize moving image data that has been recorded. In the embodiment, normally, a plurality of frames are present as the candidates for one moving image file.  
         [0034]    The thumbnail candidate data generated by the JPEG circuit  105  is sent through the data bus  115  to the format unit  107 . The format unit  107  temporarily stores the received thumbnail candidate data in the work memory  108 , and then outputs the data to the recording and reproducing unit  109  at a predetermined timing. A recording timing of the thumbnail candidate data will be described later. The recording and reproducing unit  109  records the thumbnail candidate data in a predetermined position in the moving image file to be recorded on the disk D.  
         [0035]    The servo circuit  110  properly controls rotation of the disk D or a posture of the pickup so as to enable the data to be correctly recorded and reproduced. The system control unit  111  controls an operation of the entire apparatus so as to match the components with one another.  
         [0036]    The system control unit  111  interprets a key input from the key operation unit  112  (e.g., “RECORDING START”, “REPRODUCING START”, “STOP” or the like), and controls an operation of the entire camcorder  100 .  
         [0037]    [0037]FIG. 2 shows a file format of a moving image file recorded on the disk D by the camcorder  100  of the embodiment.  
         [0038]    The file format includes areas of a header  201 , moving image data  202  and a footer  203 , arranged in this order from a file head. The moving image data area  202  stores a moving image stream encoded by the MPEG circuit  104 . The footer area  203  stores the above-described thumbnail data by a plurality of frames. The header area  201  stores additional information of the moving image data such as a length of the moving image data area  202  and a title, as well as a pointer indicating a thumbnail image of one frame selected as a representative thumbnail corresponding to the moving image data from the plurality of thumbnail candidate data stored in the footer area  203 .  
         [0039]    Next, description is made of an operation when a moving image is actually recorded.  
         [0040]    According to the embodiment, a user can control recording start and end by operating “RECORDING START” and “RECORDING END” keys included in the key operation unit  112 , and one moving image file is formed at each time when recording is ended. For each instruction of recording start and end, a plurality of moving image files having different picture recording time are recorded on the disk D.  
         [0041]    When the user operates the “RECORDING START” key to instruct recording to be started, the format unit  107  and the recording and reproducing unit  109  secure header and footer areas on the disk D according to an instruction from the system control unit  111 , and then start recording of an encoded moving image stream into a moving image data area.  
         [0042]    Simultaneously with the starting of the moving image data recording, the JPEG circuit  105  starts generation of thumbnail candidate data according to the instruction of the system control unit  111 . That is, the JPEG circuit  105  extracts one frame from moving image data outputted from the camera signal processing unit  102  at every fixed period after starting of a head frame of the moving image data to be recorded, reduces the extracted frame to a proper picture size, and then encodes the reduced frame according to JPEG Standard to generate thumbnail candidate data.  
         [0043]    In this case, to generate the thumbnail candidate data, not only one frame is merely extracted from the moving image data at every fixed period but the extraction operation can be combined with much higher level processing, for example a recognizing of great change of a content of an image by using special image recognizing means to extract a frame of such the image.  
         [0044]    The thumbnail candidate data generated in such the manner are then sent in the order of generation through the data bus  115  to the format unit  107 . The format unit  107  temporarily stores the received thumbnail candidate data in the work memory  108 .  
         [0045]    When the user operates the “RECORDING END” key, the format unit  107  and the recording and reproducing unit  109  end the recording of the moving image data into the moving image data area on the disk D according to instruction from the system control unit  111 , then read the thumbnail candidate data from the work memory  108 , and record the read data into the footer area on the disk D. Also, data attached to the moving image information is recorded into the header area on the disk D at this time.  
         [0046]    The reason why data is recorded into the header area after the instruction of the recording stop is that the header area contains information not established until the end of recording, such as a length of moving image data, and the data must be recorded after the user instructs a recording end. Such additional information contains pointer information indicating a representative thumbnail among the thumbnail candidate data of the plurality of frames stored in the footer. In the first recording, for example, thumbnail candidate data corresponding to a head frame among the plurality of thumbnail candidate data is indicated by the pointer information.  
         [0047]    Thus, the moving image file recorded on the disk D stores the moving image stream encoded according to MPEG in the moving image data area, the additional information of the moving image data in the header area, and the plurality of thumbnail candidate data in the footer area.  
         [0048]    Next, description is made of a basic operation flow in reproducing.  
         [0049]    According to the embodiment, the user can instruct reproducing start and end by operating “REPRODUCING START” and “REPRODUCING STOP” keys included in the key operation unit  112 .  
         [0050]    Since the plurality of moving image files have been recorded on the disk D as described above, actually, the user must instruct which moving image file should be reproduced before reproducing is started.  
         [0051]    In the embodiment, while the camcorder  100  is in a stopped state, the system control unit  111  reproduces the representative thumbnail image data from the moving image files on the disk D, and controls each circuit of the camcorder  100  to display the representative thumbnail image on the display unit  103  as shown in FIG. 3. The user specifies a target moving image file among such representative thumbnail images displayed on the display unit  103  by operating the key operation unit  112 .  
         [0052]    As shown in FIG. 3, a display picture screen  301  of the representative thumbnails also displays a focus mark (indicated by a thick frame  302  in FIG. 3) indicating one of the thumbnails. The user moves this focus mark  302  by using a “TO NEXT” button or a “BACKWARD” button included in the key operation unit  112  to specify a target file.  
         [0053]    Whet the user specifies the file and operates the “REPRODUCING START” key, the system control unit  111  controls the recording and reproducing unit  109  to reproduce data of the specified moving image file from the disk D. The format unit  107  processes the reproduced moving image file to detect a moving image stream, and outputs the moving image stream through the data bus  115  to the MPEG circuit  104 . The MPEG circuit  104  decodes the outputted moving image data, and sends the decoded data through the base band data bus  114  to the display unit  103  and the AV I/O unit  113 .  
         [0054]    The display unit  103  displays a moving image related to the moving image data outputted through the data bus  114  on the liquid crystal panel. The AV I/O unit  113  sends the moving image data outputted through the data bus  114  to an external television monitor or the like.  
         [0055]    The moving image stream that has been outputted through the data bus  115  to the MPEG circuit  104  is also fetched in the network I/F  106 , converted into a format conformed to Standard of IEEE1394, and sent through the terminal  116  to the network.  
         [0056]    As described above, in the embodiment, while the camcorder  100  is in a stopped state, the representative thumbnails of the moving image files are left being displayed on the display unit  103  as shown in FIG. 3.  
         [0057]    In FIG. 3, T 1  to T 6  represent representative thumbnail images of six different moving image files, and a situation of recording of six moving image files on the disk D is shown. The thumbnails T 1  to T 6  of FIG. 3 are thumbnail images indicated by pointers stored in the header area of the moving image file, and each is a head frame of moving image data when photographing of each moving image file is just finished.  
         [0058]    As described above, when the head frame is used as a representative thumbnail, it is not always a real help to selection of a moving image file.  
         [0059]    For example, if moving image data corresponding to the representative thumbnail T 2  in FIG. 3 is started in the fading-in manner from a black picture screen, the thumbnail T 2  as its head frame is a totally black picture, not reflecting a content of the moving image file.  
         [0060]    According to the embodiment, even in such the case, the user can optionally specify a much better representative thumbnail by the following process.  
         [0061]    That is, while the representative thumbnail of each moving image file is displayed on the display unit  103 , the user focuses on the thumbnail T 2  by using the “TO NEXT” or “BACKWARD” button included in the key operation unit  112 , and specifies a thumbnail selection mode by operating a “SELECTION MODE” key also included in the key operation unit  112 .  
         [0062]    Hereinafter, description is made of processing of the system control unit on the thumbnail selection mode by referring to FIGS. 4 and 5.  
         [0063]    [0063]FIG. 4 shows a content displayed on the display unit  103  in the thumbnail selection mode; and FIG. 5 a flowchart showing an operation of the system control unit  111  in the thumbnail selection mode.  
         [0064]    When the thumbnail selection mode is started while the focus mark  302  is set in the thumbnail T 2 , the system control unit  111  controls the recording and reproducing unit  109  to read data stored in a position of a first thumbnail candidate in a footer area of a moving image file corresponding to the thumbnail T 2  in step S 501 . Then, in step S 502 , determination is made as to whether the read data is thumbnail candidate data or not based on reproduced data. If YES, in step S 503 , the thumbnail candidate data is decoded by the JPEG circuit  105 , and then displayed as t 1  on the display unit  103  as shown in  401  of FIG. 4.  
         [0065]    If the data read in step S 502  is not thumbnail candidate data, then the thumbnail selection mode is finished.  
         [0066]    After the displaying of the thumbnail candidate t 1  in step S 503 , in step S 504 , the process waits for user&#39;s determination as to whether or not to select the thumbnail candidate t 1  as a thumbnail. The thumbnail candidate t 1  displayed here is a head frame, the same as T 2 .  
         [0067]    The user can enter selection/non-selection of an image of the displayed thumbnail candidate by using an “ESTABLISH” key or the “TO NEXT” key included in the key operation unit  112 . If the user operates the “ESTABLISH” key to enter establishment of the displayed thumbnail key t 1  as a thumbnail, the format unit  107  and the recording and reproducing unit  109  are controlled in step S 506  to register the thumbnail candidate t 1  as a representative thumbnail of the moving image file. That is, a pointer indicating the thumbnail candidate t 1  is written in a predetermined place in a header area of the moving image file, and then the thumbnail selection mode is finished.  
         [0068]    If the user operates the “TO NEXT” key to enter non-establishment of the displayed thumbnail candidate t 1  as a thumbnail, in step S 505 , the recording and reproducing unit  109  reproduces next thumbnail candidate data. Then, in step S 502 , determination is made again as to whether the reproduced data is a thumbnail candidate or not.  
         [0069]    If the read data is a thumbnail candidate t 2 , in step S 503 , thumbnail candidate data is decoded similarly to the above, to be displayed on the display unit  103  as shown in  402  of FIG. 4, and the process waits for user&#39;s determination in step S 504 .  
         [0070]    Thus, the thumbnail selection mode repeats a processing loop until no more thumbnail candidates are present, and then comes to an end. For example, if a thumbnail candidate t 3  is determined to best represent a feature of the moving image file, the user establishes the thumbnail candidate t 3  as a representative thumbnail. Thereafter, the set thumbnail t 3  is displayed as a representative thumbnail T 2  in place of the thumbnail of the totally black picture screen.  
         [0071]    Thus, according to the embodiment, in recording of the moving image file, image data of a plurality of thumbnail candidates are extracted from recorded moving image data by a predetermined timing, and stored in a moving image file. After the recording, an image to be used as a representative thumbnail can be selected from the plurality of thumbnail candidates. Accordingly, it is possible to set a thumbnail image best indicating a content of the moving image file by a simple configuration, greatly helping user&#39;s selection of a moving image file.  
         [0072]    In the embodiment, when the representative thumbnail is set, as shown in FIG. 4, the thumbnails of the target moving image file are switched from one picture screen to another, i.e., t 1  to t 2 , and t 2  to t 3 . Other than this arrangement, a list of still images of a plurality of frames as thumbnail candidates may be displayed on the same picture screen, enabling the user to select a representative thumbnail by comparing the thumbnail candidates list-displayed with one another.  
         [0073]    Next, description is made of a second embodiment by referring to FIG. 1 as in the case of the first embodiment.  
         [0074]    In the first embodiment, the thumbnail candidates were generated when photographing is performed. In the present embodiment, however, thumbnail candidates are generated by using moving image data recorded already in a disk D. Functions of the elements shown in FIG. 1 are similar to those of the first embodiment. Also, operations other than those in thumbnail candidate generation are similar to those (operations at photographing and recording, reproducing, and on the representative thumbnail selection mode).  
         [0075]    Also in the present embodiment, as described above, recording of moving image data is started according to instruction of a recording start by a key operation unit  112  and, simultaneously, thumbnail candidate generation by a JPEG circuit  105  is carried out. After recording of a moving image file is finished according to instruction of a recording end, a user operates a “THUMBNAIL CANDIDATE GENERATION PERMIT” key of the key operation unit  112  to start off-line thumbnail candidate generation.  
         [0076]    In the embodiment, the thumbnail candidate generation is executed as a background job. Upon reception of instruction of thumbnail candidate generation, a system control unit  111  controls a recording and reproducing unit  109  to reproduce moving image data from the disk D, and sends encoded moving image data stream through a format unit  107  and a data bus  115  to an NPEG circuit  104 . The MPEG circuit  104  decodes the received moving image data, and sends the decoded data to a data bus  114 .  
         [0077]    On a normal reproducing mode, the moving image data sent to the data bus  114  is outputted to a display unit  103  and an AV I/O unit  113 . However, since the thumbnail candidate generation is executed as the background job, the moving image data is not outputted to the display unit  103  or the AV I/O unit  113 , but fetched by the JPEG circuit  105 .  
         [0078]    According to instruction from the system control unit  111 , the JPEG circuit  105  extracts at a predetermined timing image data of one frame from the moving image data fetched through the data bus  114 , generates thumbnail candidate data, and sends the generated data through the data bus  115  to the format unit  107  again. The format unit  107  temporarily stores the received thumbnail candidate data in a work memory  108 .  
         [0079]    After an end of the reproducing of the moving image data of one moving image file, the generation of thumbnail candidates by the JPEG circuit  105  is also finished. After an end of the generation of all thumbnail candidate data, the format unit  107  outputs the thumbnail candidate data stored in the work memory  108  to the recording and reproducing unit  109 . The recording and reproducing unit  109  records these thumbnail candidate data in a footer area of the original moving image file in addition to the thumbnail candidate data generated at recording.  
         [0080]    A process thereafter is similar to that of the first embodiment, i.e., selection of a representative thumbnail described above with reference to FIGS. 4 and 5.  
         [0081]    For example, if an extracting interval of thumbnail candidates extracted at photographing is too long, the configuration of the embodiment enables thumbnail candidates to be regenerated at a shorter interval. Thus, more effective thumbnail candidates can be obtained, thereby making it possible to specify a more proper representative thumbnail.  
         [0082]    Next, description is made of a third embodiment of the invention.  
         [0083]    Even when a moving image file formed by the camcorder of FIG. 1 is moved or copied to another apparatus or system as described above, the moving image file still contains a plurality of thumbnails. Thus, a representative thumbnail can be easily set again at the moving or copying destination.  
         [0084]    Even in the case of a moving image file having a similar content, an optimal representative thumbnail may change depending on an environment. For example, there may be a case that a moving image file having a similar content may have been already saved in a recording medium of the copying destination. Even in this case, the configuration of the embodiment enables the user to easily set a thumbnail again.  
         [0085]    Next, description is made of an embodiment, where the invention is applied to a personal computer (PC) incorporating a recording medium having a copied moving image file formed by the camcorder of FIG. 1.  
         [0086]    [0086]FIG. 6 is a block diagram showing an internal configuration of a PC  600 , to which the invention is applied.  
         [0087]    A reference numeral  601  denotes a processor including not only a CPU but also a peripheral circuit such as an external memory;  602  a memory unit including a hard disk drive (HDD);  603  a key interface (I/F) including pointing devices, i.e., a key board, a mouse and the like, and adapted to process inputs from a user;  604  a display including a monitor and a display control circuit, and adapted to process displaying to the user;  605  a network interface (I/F); and  606  a network terminal.  
         [0088]    [0088]FIG. 7, is a functional block diagram showing software programs used in the PC  600 .  
         [0089]    A reference numeral  704  denotes a file system module for controlling the HDD  602  to provide file system services to a higher layer;  705  a network interface module for controlling the network I/F  605  to provide network services to the higher layer;  702  a moving image encoding/decoding (moving image CODEC) module; and  703  a still image encoding/decoding (still image CODEC) module respectively for providing moving and still image encoding/decoding services to the upper layer, both  702  and  703  being intermediate modules using only resources of the processor  601 . A reference numeral  701  denotes a user interface (UI) module for controlling the key I/F  603  and the display  604  to input/output data from/to a user. In addition, the UI module  701  controls the entire software programs of the embodiment according to the input/output information from/to the user.  
         [0090]    Next, description is made of a basic operation flow in reproducing in the embodiment.  
         [0091]    In the embodiment, the user controls the system by using graphic user interface (GUI) realized by the UI module  701  using the display  604  and the key I/F  603 .  
         [0092]    Specifically, by clicking a “REPRODUCING START” button or a “REPRODUCING STOP” button displayed on the monitor of the display  604  with the mouse which is a pointing device included in the key I/F  603 , the user can control a reproducing start or stop.  
         [0093]    As described above, the HDD  602  of the present embodiment stores therein a plurality of moving image files generated by the camcorder  100  shown in FIG. 1. Thus, a user has to instruct which moving image file should be reproduced, before start of reproduction.  
         [0094]    In the present embodiment, when the software program is not reproducing any moving image files, the processor  601  reads and decodes representative thumbnail image data of each moving image file stored in the HDD  602 , and the representative thumbnail images are displayed on the monitor of the display  604  as shown in FIG. 3.  
         [0095]    The user specifies a target moving image file among the displayed images. As shown in FIG. 3, a display picture screen of the representative thumbnails displays a focus mark  302  indicating one of the images, and the user can specify a target file by pressing a “TO NEXT” button or a “BACKWARD” button provided in GUI on the monitor.  
         [0096]    When the user specifies the file and clicks the “REPRODUCING START” button, the file system module  704  reads the target moving image file stored in the HDD  604 , and passes the file to the moving image CODEC module  702 . The moving image CODEC module  702  decodes the received moving image data, and passes the decoded data to the UI module  701 . The UI module  701  displays the reproduced moving image on the display  604 .  
         [0097]    As described above, in the embodiment, when the software program is not reproducing any moving image files, the representative thumbnails of the moving image files are displayed on the monitor of the display  604  as shown in FIG. 3.  
         [0098]    The user specifies an image among the thumbnail images corresponding to the target moving image file.  
         [0099]    Reference numerals T 1  to T 6  in FIG. 3 denote representative thumbnails of the moving image files. Here, a case of six moving image files recorded in the HDD  604  is specifically shown. The thumbnails T 1  to T 6  shown in FIG. 3 are thumbnail images indicated by pointers stored in header areas of the moving image files.  
         [0100]    As described above, the representative thumbnail images are not always accurate representation of contents of the moving image files. In addition, as described above with reference to the first embodiment, even if proper representative thumbnails have been set in the camcorder, the representative thumbnail images do not always still remain proper after data copying in the PC system.  
         [0101]    For example, it is conceivable that a moving image file of a similar content has been already stored in the hard disk drive of the PC. In this case, a representative thumbnail image must be specified again. According to the embodiment, a more proper representative thumbnail can be specified by the following process.  
         [0102]    While the representative thumbnail images are displayed on the display  604  as shown in FIG. 3, the user operates the “TO NEXT” or “BACKWARD” button included in GUI displayed on the display  604  by the key I/F  603 , to set a focus mark  302  to T 2  of FIG. 3, and then clicks a “SELECTION MODE” button similarly included in GUI by the Key I/F  603  to set the system on a thumbnail selection mode.  
         [0103]    [0103]FIG. 4 shows a content displayed on the display  604  on the thumbnail selection mode; and FIG. 5 a flowchart showing an operation of the processor  601  on the thumbnail selection mode of the embodiment.  
         [0104]    Hereinafter, description is made of processing of the PC  600  on the thumbnail selection mode by referring to FIGS. 4 and 5.  
         [0105]    When the thumbnail selection mode is started while a focus is set in the thumbnail T 2  shown in FIG. 3, the file system module  704  of the processor  601  reads data stored in a position of a first thumbnail candidate in a footer area of a moving image file corresponding to the thumbnail T 2  from the HDD  602  in step S 501 .  
         [0106]    Then, in step S 502 , determination is made based on reproduced data, as to whether the read data is thumbnail candidate data or not. If YES, in step S 503 , the thumbnail candidate data is decoded by the still image CODEC module  703 , and then displayed as t 1  on the display  604  as shown in  401  of FIG. 4.  
         [0107]    If the data read in step S 502  is not thumbnail candidate data, then the thumbnail selection mode is finished.  
         [0108]    After the displaying of the thumbnail candidate t 1  in step S 503 , in step S 504 , the process waits for user&#39;s determination as to whether or not to select the displayed thumbnail candidate t 1  as a thumbnail. The thumbnail candidate t 1  displayed here is a head frame, the same as T 2 .  
         [0109]    The user can enter selection/non-selection of an image of the displayed thumbnail candidate by using an “ESTABLISH” button or the “TO NEXT” button included in the key I/F  603 . If the user operates the “ESTABLISH” button to enter establishment of the displayed thumbnail key t 1  as a thumbnail, the file system module  704  registers the thumbnail candidate t 1  as a representative thumbnail of the moving image file in step S 506 . That is, a pointer indicating the thumbnail candidate t 1  is written in a predetermined place in a header area of the moving image file, and then the thumbnail selection mode is finished.  
         [0110]    If the user presses the “TO NEXT” button to enter non-establishment of the displayed thumbnail candidate t 1  as a thumbnail, in step S 505 , the file system module  704  reproduces next thumbnail candidate data by the recording and reproducing unit  109 . Then, in step S 502 , determination is made again as to whether the reproduced data is a thumbnail candidate or not.  
         [0111]    If the read data is a thumbnail candidate t 2 , in step S 503 , the thumbnail candidate data is decoded by the still image CODEC module  703  similarly to the above, to be displayed on the display  604  as shown in  402  of FIG. 4, and the process waits for user&#39;s determination in step S 504 .  
         [0112]    Thus, the thumbnail selection mode repeats a processing loop until no more thumbnail candidates are present, and then comes to an end. For example, if a thumbnail candidate t 3  is determined to best represent a feature of the target moving image file, the user establishes the thumbnail candidate t 3  as a representative thumbnail. Thereafter, the set thumbnail t 3  is displayed as a representative thumbnail T 2 .  
         [0113]    Thus, according to the embodiment, even when a moving image file having a plurality of thumbnail candidates is copied to the external apparatus such as a PC, an image to be used as a representative thumbnail can be selected from the plurality of thumbnail candidates at the PC which is the copying destination. Therefore, it is possible to easily set a thumbnail image again at the copying destination.  
         [0114]    Next, description is made of a fourth embodiment of the invention.  
         [0115]    In the previous embodiments, the thumbnail image was set again by using the camcorder or the PC singly. Needless to say, however, the embodiment can be applied to a system having the camcorder and the PC interconnected through a network.  
         [0116]    The fourth embodiment is now described by way of example, where the invention is applied to a system composed of a camcorder and a PC, a moving image file photographed by the camcorder and recorded in a disk is controlled by the PC connected through a network to select a representative thumbnail proper for the moving image file.  
         [0117]    [0117]FIG. 8 is a block diagram showing a configuration of a system  800 , to which the invention is applied. The system  800  of FIG. 8 includes a camcorder  100  shown in FIG. 1 and a PC  600 , which are interconnected through a network N.  
         [0118]    In the system  800  of FIG. 8, a network terminal  116  of FIG. 1 and a network terminal  606  of FIG. 6 are interconnected through the network N to enable bidirectional communication to be performed. For a physical layer of communication, a serial bus of IEEE1394 is used as described above, and thus command and file data transfer can be carried out.  
         [0119]    The components, i.e., the camcorder  100  and the PC  600  of FIG. 8 are similar to those described above. Also, a functional block of software programs of the PC system  600  shown in FIG. 7 is similar to that described above. A photographed moving image file is recorded in a disk D of FIG. 1, and this recording operation is also similar to that of the first embodiment.  
         [0120]    Next, detailed description is made of operations in reproducing and representative thumbnail specification.  
         [0121]    First, description is made of a basic operation flow of reproducing according to the embodiment.  
         [0122]    In the embodiment, a user controls an operation of the system  800  by using GUI provided by a UI module  701  of the PC  600  shown in FIG. 7.  
         [0123]    Specifically, the user can control a reproducing start or end by clicking a “REPRODUCING START” or “REPRODUCING END” button displayed on a monitor of a display  604  of FIG. 6 with a mouse included in a key I/F  603 .  
         [0124]    On the other hand, a plurality of moving image files have been already recorded in the disk D of FIG. 1, and the user must specify before a start of reproducing, which moving image file should be reproduced.  
         [0125]    In the embodiment, when a software program of the PC system  600  is not reproducing any moving image file and the camcorder  100  is in a stopped state, representative thumbnails of moving image files recorded on the disk D are displayed on the display  604  of the PC  600  as shown in FIG. 3. The user specifies a target moving image file among the displayed files.  
         [0126]    Specifically, a network I/F module  705  of FIG. 7 controls the network I/F  605  of FIG. 6, to issue a control command to the camcorder  100  to reproduce the representative thumbnail of each moving image file recorded in the disk D and send it to the PC  600 .  
         [0127]    In the camcorder  100 , a network I/F  106  recognizes the command, and notifies a content of the command to a system control unit  111 . The system control unit  111  controls the recording and reproducing unit  109  according to this control command to reproduce image data of the representative thumbnail of each moving image file recorded on the disk D, and output the reproduced data through a format unit  107  and a data bus  115  to the network I/F  106 . The network I/F  106  changes the received thumbnail image data, that is, image data subjected to JPEG encoding, according to a format of IEEE1394, and outputs the changed image data through the terminal  116  to the PC  600 .  
         [0128]    A network I/F  605  of the PC  600  outputs the received representative thumbnail image data to a processor  601 . The processor  601  detects that the data entered from the network I/F module  705  is representative thumbnail image data, and the UI module  701  displays the representative thumbnail image on the display  604  as shown in FIG. 3.  
         [0129]    As shown in FIG. 3, a display picture screen of representative thumbnails displays a focus mark  302  indicating one of the thumbnails. The user can specify a target file by moving the focus mark  302  using a “TO NEXT” or “BACKWARD” button provided in GUI. When the user specifies a file and clicks a “REPRODUCING START” button, this information is sent from the UI module  701  of FIG. 7 to the network I/F module  705 , and then transmitted from the processor  601  of FIG. 6 through the network I/F  605  and the network terminal  606  to the camcorder  100 .  
         [0130]    In the camcorder  100 , when the network terminal  116  receives a command of a reproducing start, the network I/F circuit  106  interprets the reproducing start command, and reports it to the system control unit  111 . Then, according to instruction of the system control unit  111 , the recording and reproducing unit  109  reads the specified moving image file from the disk D, and detects a moving image stream by decoding and unpacketizing of the disk file system at the format unit  107 . The reproduced moving image stream is passed as an MPEG stream through the data bus  115  to the network I/F circuit  106 .  
         [0131]    The network I/F circuit  106  packetizes the received moving image stream according to IEEE1394 Standard, and sends it through the network terminal  116  to the PC system  600 .  
         [0132]    In the PC system  600 , when the moving image stream is received by the network terminal  606 , the data is sent through the network I/F  605  to the processor  601 . In the processor  601 , an IEEE1394 packet is unpacketized by the network I/F module  705  shown in FIG. 7 to recompose an original MPEG stream, and then this moving image data is passed to a moving image CODEC module  702 . The moving image CODEC  702  decodes the received moving image data, and sends the decoded data to the UI module  701 . The UI module  701  displays the reproduced moving image on the display  604 .  
         [0133]    According to the embodiment, if a software program of the PC  600  is not processing the moving image file reproduced from the disk D of FIG. 1, the representative thumbnails of the moving image files recorded on the disk D are displayed on the display  604  as shown in FIG. 3. The user specifies a target moving image file among the displayed files.  
         [0134]    In the embodiment, as in the case of the previous embodiments, the user can optionally change the displayed representative thumbnails.  
         [0135]    For example, to change a representative thumbnail T 2 , the user operates the “TO NEXT” or “BACKWARD” button included in GUI displayed on the display  604  by the UI module  701 , to set a focus mark  302  to T 2 , and then clicks a “SELECTION MODE” button similarly included in GUI to set the system on a thumbnail selection mode.  
         [0136]    [0136]FIG. 1 shows a content displayed on the display  604  on the thumbnail selection mode.  
         [0137]    When the thumbnail selection mode is started while a focus is set on the thumbnail T 2 , the UI module  701  specifies reproducing of data located in a place of a first thumbnail candidate in a footer area of a moving image file corresponding to T 2 . This command is transmitted not to the file system module  704  but to the network I/F module  705 .  
         [0138]    At the network I/F module  705 , the command is converted into a command defined in IEEE1394 meaning “DATA ACQUISITION OF FIRST THUMBNAIL CANDIDATE”, and then sent from the processor  601  through the network I/F  605  and the network terminal  606  to the camcorder  100 .  
         [0139]    In the camcorder  100 , upon reception of the command at the network I/F  116 , the network I/F circuit  106  interprets the command of “DATA ACQUISITION OF FIRST THUMBNAIL CANDIDATE”, and reports it to the system control unit  111 . Upon receiving the command, the system control unit  111  controls the recording and reproducing unit  109  to read out data of a first thumbnail candidate recorded in a footer area of the specified moving image file among the moving image files recorded on the disk D, and output the read-out data to the format unit  107 .  
         [0140]    The format unit  107  performs decoding and packetizing of the disk file system on the reproduced data, and outputs the processed data as the data of the first thumbnail candidate to the network I/F circuit  106  through the data bus  115 .  
         [0141]    The network I/F circuit  106  converts the reproduced thumbnail candidate data into a format conformed with IEEE1394, to send the converted data through the network terminal  116  to the PC system  600 .  
         [0142]    In the PC system  600 , upon reception of the data including the thumbnail candidate at the network terminal  606 , the data is outputted through the network I/F  605  to the processor  601 . In the processor  601 , the network I/F module  705  shown in FIG. 7 unpacketizes the data packet of the IEEE1394 format, and passes it to the UI module  701 .  
         [0143]    The UI module  701  analyzes the received data to determine whether or not the candidate is a real thumbnail candidate and, if YES, sends the thumbnail candidate data to a still image CODEC module  703 . The still image CODEC module  703  decodes this thumbnail candidate data, and the UI module  701  displays the decoded thumbnail image data on the display  604  as indicated by t 1  in  401  of FIG. 4. If the data sent from the camcorder  100  is not a thumbnail candidate, the thumbnail selection mode is finished.  
         [0144]    After the displaying of the thumbnail candidate t 1 , the UI module  701  waits for user&#39;s determination as to whether the displayed thumbnail candidate t 1  is selected as a representative thumbnail or not. The user can enter own determination by operating the key I/F  603  to instruct an “ESTABLISH” or “TO NEXT” button displayed on the display  604 .  
         [0145]    If the user clicks the “ESTABLISH” button to establish the displayed thumbnail candidate t 1  as a thumbnail, the thumbnail candidate t 1  is registered as a representative thumbnail of the moving image file. That is, a pointer indicating the thumbnail candidate t 1  is written in a predetermined area of a header area of the moving image file, and then the thumbnail selection mode is finished. This operation is achieved in the following manner.  
         [0146]    The operation of the “ESTABLISH” button by the user is notified from the UI module  701  to the network I/F module  705 . The network I/F module  705  generates a command of IEEE1394 meaning “REGISTRATION OF THUMBNAIL CANDIDATE t 1  AS REPRESENTATIVE THUMBNAIL” according to the operation instruction, and sends the command from the processor  601  through the network I/F  605  and the network terminal  606  to the camcorder  100 .  
         [0147]    In the camcorder  100 , upon reception of the command at the network terminal  116 , the network I/F circuit  106  interprets the command of “REGISTRATION OF THUMBNAIL CANDIDATE t 1  AS REPRESENTATIVE THUMBNAIL”, and reports it to the system control unit  111 . The system control unit  111  controls the format unit  107  and the recording and reproducing unit  109  to write a pointer indicating the thumbnail candidate t 1  recorded in a footer area of the specified moving image file of the disk D as a representative thumbnail in a predetermined area of a header area of the moving image file, and the thumbnail selection mode is finished.  
         [0148]    If the user clicks the “TO NEXT” button not to establish the displayed thumbnail candidate t 1  as a thumbnail, data of a next thumbnail candidate is read out. This operation is achieved in the following manner.  
         [0149]    The operation of the “TO NEXT” button by the user is notified from the UI module  701  to the network I/F module  705 . The network module  705  generates a command of IEEE1394 meaning “DATA ACQUISITION OF NEXT THUMBNAIL CANDIDATE” according to the operation instruction, and sends the command through the network I/F  605  and the network terminal  606  to the camcorder  100 .  
         [0150]    In the camcorder  100  side, upon reception of the command at the network terminal  116 , the network I/F circuit  106  interprets the command of “DATA ACQUISITION OF NEXT THUMBNAIL CANDIDATE”, and reports it to the system control unit  111 . The system control unit  111  controls the recording and reproducing unit  109  according to the command to read out data of a second thumbnail candidate recorded in the footer area of the specified moving image file of the disk D, and send the read-out data to the format unit  107 .  
         [0151]    The format unit  107  performs decoding and packetizing of the disk file system on the reproduced data, to output the processed data as the data of the next thumbnail candidate to the network I/F circuit  106  through the data bus  115 . The network I/F circuit  106  converts the data into a format conformed with IEEE1394, sends the converted data through the network terminal  116  to the PC system  600 .  
         [0152]    In the PC system  600 , upon reception of the data at the network terminal  606 , the data is outputted through the network I/F  605  to the processor  601 . In the processor  601 , the network I/F module  705  unpacketizes the data packet of the IEEE1394 format, and passes it to the UI module  701 . The UI module  701  analyzes the received data to determine whether the data indicates a thumbnail candidate or not.  
         [0153]    If the read-out data indicates the thumbnail candidate, then as in the case of t 1 , the data of the thumbnail candidate is sent to the still image CODEC module  703 . The still image CODEC module  703  decodes this thumbnail candidate data, and sends the decoded data again to the UI module  701 . The UI module  701  displays the decoded thumbnail image data on the display  604  as indicated by t 2  in  402  of FIG. 4, and waits for user&#39;s determination again.  
         [0154]    Thus, the thumbnail selection mode repeats a processing loop until no more thumbnail candidates are present. Here, for example, if a thumbnail candidate t 3  shown in  403  of FIG. 4 best represents features of the target moving image file, the user establishes the thumbnail candidate t 3  as a representative thumbnail, and this t 3  is displayed as a representative thumbnail t 2  thereafter.  
         [0155]    As described above, according to the present embodiment, even when the camcorder and the PC system are interconnected through the network, the camcorder and the PC system can select a representative thumbnail while transferring a command or data with each other. Generally, the PC system  600  has a monitor of higher resolution compared with the camcorder  100 , and has less constraints on displaying. Thus, it is possible to facilitate the operation of selecting a representative thumbnail from the thumbnail candidates by using GUI of higher definition.  
         [0156]    Next, description is made of a fifth embodiment of the invention.  
         [0157]    In the above-described fourth embodiment, the plurality of thumbnail candidates are formed simultaneously with the recording of the moving image file by the camcorder  100 , and the user sets the representative thumbnail among the plurality of thumbnail candidate by the PC. However, as described above with reference to the second embodiment, processing for forming a thumbnail candidate from moving image data recorded in the disk D can be similarly carried out by controlling the camcorder  100  from the PC  600  side in the system shown in FIG. 8.  
         [0158]    The fifth embodiment is now described by way of example, where a camcorder is controlled by a PC connected to the camcorder through a network, and thumbnail candidates are generated and added by using moving image files that have been already recorded in a disk.  
         [0159]    The camcorder, the PC and a configuration of a system composed of the camcorder and the PC are similar to those shown in FIGS. 1, 6 and  8 . Also, an operation in photographing by the camcorder  100  is similar to that of the first embodiment, and operations in reproducing and on a representative thumbnail selection mode are similar to those of the fourth embodiment.  
         [0160]    Hereinafter, description is made of thumbnail candidate data generation according to the embodiment.  
         [0161]    According to the present embodiment, as described above with reference to the third or fourth embodiment, a user can control an operation of a system by using GUI achieved by a UI module  701  shown in FIG. 7 using a display  604  and a key I/F  603  of FIG. 6.  
         [0162]    When the user clicks a “PERMISSION OF THUMBNAIL CANDIDATE GENERATION” button displayed on the display  604 , thumbnail candidate generation is started. The thumbnail candidate generation is executed as a background job so as not to interfere with other operations while a software program of a PC system  600  is not reproducing any moving image files and the camcorder  100  is in a stopped state.  
         [0163]    When the generation of thumbnail candidates is instructed, the UI module  701  of FIG. 7 instructs a network I/F module  705  to reproduce target moving image data. This command is converted into a communication command by the network I/F module  705 , and sent through a network I/F  605  and a network terminal  606  to the camcorder  100 .  
         [0164]    In the camcorder  100  side, upon reception of the command at a network terminal  116 , a network I/F circuit  106  interprets the moving image acquisition command, and reports it to a system control unit  111 . The system control unit  111  controls a recording and reproducing unit  109  according to the command to read out a specified moving image file from a disk D, and output the read-out file to the format unit  107 . The format unit  107  performs decoding and packetizing of a disk file system on the reproduced moving image file data to take out a moving image data stream, and outputs the data stream through a data bus  115  to -the network I/F circuit  106 . The network I/F circuit  106  converts the reproduced moving image stream into a format conformed with IEEE1394 to send the converted stream through a network terminal  116  to the PC system  600 .  
         [0165]    In the PC system  600 , upon reception of the data at the network terminal  606 , the data is outputted through the network I/F  605  to a processor  601 . In the processor  601 , a network I/F module  705  unpacketizes a packet of IEEE1394 to reconstruct an original MPEG stream, and passes the moving image data to a moving image CODEC module  702 .  
         [0166]    The moving image CODEC module  702  decodes the received moving image data, and passes the decoded data to a UI module  701 . On a normal reproducing mode, the UI module  701  displays a reproduce moving image on the display  604 . In the thumbnail candidate generation, however, since decoding is carried out as a background job, no reproduced moving images are displayed on the display  604 .  
         [0167]    The UI module  701  extracts data of a frame as a thumbnail candidate from the decoded moving image data at a predetermined timing, and sends the extracted data to a still image CODEC module  703 . Generally, since the PC  600  has a higher data processing capability than the camcorder  100 , it is possible to make determination of a higher level using image processing when a frame as a thumbnail candidate is extracted.  
         [0168]    For example, a correlation with a preceding frame or a subsequent frame is calculated, and various thumbnail candidates can be generated by extracting a frame of a lower correlation.  
         [0169]    The still image CODEC module  703  generates thumbnail candidate data from image data of the extracted frame, and sends the generated data back to the UI module  701 . The UI module  701  passes the received thumbnail candidate data to a file system module  704 , and instructs an HDD  602  of FIG. 6 to temporarily store the data.  
         [0170]    When generation of all thumbnail candidates for the specified moving image file, the file system module  704  reads out data of a plurality of thumbnail candidates stored in the HDD  602  according to instruction from the UI module  701 .  
         [0171]    Then, the UI module  701  instructs the network I/F module  705  to update the thumbnail candidate. This command is converted into a communication command by the network I/F module  705 , and sent through the network I/F  605  and the network terminal  606  to the camcorder  100 .  
         [0172]    Also, in this case, the thumbnail candidate data read out from the HDD  602  by the file system module  704  is simultaneously sent to the network I/F module  705 , packetized, and then sent through the network I/F  605  and the network terminal  606  to the camcorder  100 .  
         [0173]    In the camcorder  100 , upon reception of the command and the packetized thumbnail candidate at the network terminal  116 , the network I/F circuit  106  interprets the thumbnail candidate updating command, and reports it to the system control unit  111 . The network I/F circuit  106  unpacketizes the received thumbnail candidate data, and sends it through the data bus  115  to the format unit  107 .  
         [0174]    The system control unit  111  controls the format unit  107  and the recording and reproducing unit  109  to add the received new thumbnail data as a new thumbnail candidate to a footer area of the specified moving image file on the disk D.  
         [0175]    Thus, according to the present embodiment, in the system composed of the camcorder and the PC, by controlling the reproducing operation of the camcorder from the PS side, it is possible to generate and add new thumbnail candidate data from a moving image file that has been already recorded.  
         [0176]    Next, description is made of a sixth embodiment of the invention.  
         [0177]    The sixth embodiment is described by way of example, where the invention is applied to a system including a relatively small camera having no recording or reproducing functions and a PC interconnected to that camera through a network.  
         [0178]    [0178]FIG. 10 shows a configuration of a system  1000  of the present embodiment. The system  1000  of FIG. 10 includes a camera  900  and a PC  600 , interconnected to each other through a network N. The PC  600  is similar to that shown in FIG. 6 and, also, in the present embodiment, an IEEE1394 serial bus is used for the network N.  
         [0179]    [0179]FIG. 9 is a block diagram showing a configuration of the camera  900  of FIG. 10. In FIG. 9, a reference numeral  901  denotes an image pickup unit, a CCD being used in the present embodiment;  902  a camera signal processing unit;  903  an encoding unit for performing encoding according to MPEG in the embodiment;  904  a network interface (I/F), IEEE1394 being used as a network protocol in the embodiment as described above;  905  a network terminal; and  906  a system control unit for controlling an operation of the camera  900 . The terminal  905  of FIG. 9 and the terminal  606  of FIG. 6 are connected to each other to enable bidirectional communication to be executed.  
         [0180]    The camera  900  of the present embodiment has no recording functions. Moving image data photographed by the camera  900  is sent from the network I/F  904  through the terminal  905  to the PC  600 , and stored in an HDD  602  of the PC  600 .  
         [0181]    Hereinafter, description is made of basic processing in recording in the embodiment by referring to FIGS. 6, 7,  9  and  10 .  
         [0182]    In the PC  600  of the embodiment, a user controls an operation of the system by using GUI. This operation is achieved by a UI module  701  of a software program executed by a processor  601  using a display  604  and a key I/F  603 .  
         [0183]    Specifically, a “RECORDING START” or “RECORDING END” button displayed on the display  604  is clicked by a mouse which is a pointing device included in the key I/F  603 . Accordingly, a recording start or end can be controlled.  
         [0184]    After the user clicks the “RECORDING START” button to start recording, one moving image file is recorded in the HDD  602  for each clicking of the “RECORDING END” button. A file format of the moving image file recorded in the HDD  602  is similar to that shown in FIG. 2.  
         [0185]    When the user clicks the “RECORDING START” button on GUI, its information is sent from the UI module  701  of FIG. 7 to a file system module  704  and a network I/F module  705 . The file system module  704  controls the HDD  602  to secure header and footer areas of a moving image file to be stored, and then waits for moving image data sent from the camera  900 .  
         [0186]    On the other hand, the network I/F module  705  converts the information received from the UI module  701  into a communication command, and sends the command through the network I/F  605  and the network terminal  606  to the camera  900 .  
         [0187]    In the camera  900  side, upon reception of the command at the network terminal  905 , the network I/F circuit  906  interprets the recording start command, and reports it to a system control unit  906 . The system control unit  906  controls the camera signal processing unit  902 , the encoding unit  903 , and the network I/F unit  904  according to this recording start command.  
         [0188]    Moving image data photographed by the image pickup unit  901  is subjected to signal processing at the camera signal processing unit  902 , and then sent to the encoding unit  903 . The encoding unit  903  encodes the moving images data according to MPEG 2, and outputs the encoded data to the network I/F  904 . The network I/F converts the encoded moving image data into a format conformed with IEEE1394, and sends the converted data through the network terminal  905  to the PC system  600 .  
         [0189]    In the PC system  600 , upon reception of the data outputted from the camera  900  at the network terminal  606 , the data is outputted through the network I/F  605  to the processor  601 . In the processor  601 , the network I/F module  705  of FIG. 7 unpacketizes a packet of IEEE1394 to reconstruct an MPEG stream, and then sends the moving image data -to the file system module  704  and the moving image CODEC module  702 .  
         [0190]    The file system module  704  writes the moving image data in the HDD  602 . On the other hand, the moving image CODEC module  702  decodes the received moving image data, and passes the decoded data to the UI module  701 . The UI module  701  extracts a frame as a thumbnail candidate from the decoded moving image data at a predetermined timing, and sends it to the still image CODEC module  703 .  
         [0191]    As a method of extracting a frame as a thumbnail candidate, there may be a method of extracting frames at each constant interval. However, various thumbnail candidates can be generated by various processes. For example, a correlation with a preceding frame or a subsequent frame is calculated, and a frame having a lower correlation is extracted.  
         [0192]    The still image CODEC module  703  encodes image data of the received frame according to JPEG Standard to generate thumbnail candidate data, and sends the generated data back to the UI module  701 . The UI module  701  passes the received thumbnail candidate data to the file system module  704 , and instructs the same to temporarily store the data until the user enters a recording end.  
         [0193]    When the user clicks the “RECORDING END” button on GUI, the UI module  701  controls the file system module  704  to finish the recording of the moving image data into the moving image data area of the HDD  602 , and the file system module  704  records all the temporarily stored thumbnail candidates in the footer area of the moving image file on the HDD  602 .  
         [0194]    Also, in this case, the file system module  704  stores data attached to the moving image data in the header area. This additional information contains pointer information indicating a representative thumbnail. In first recording, a pointer indicating a thumbnail candidate corresponding to, for example a head frame among the thumbnail candidates in the footer area is recorded.  
         [0195]    As described above, for the moving image file recorded in the HDD  602 , the MPEG-encoded moving image stream is stored in the moving image data area, the additional information of the moving image data in the header area, and the plurality of thumbnail candidates in the footer area. Thus, in the PC  600 , after the recording of the moving image file in the representative thumbnail selection mode described above with reference to the fourth embodiment, the user can select a proper representative thumbnail. Moreover, it is possible to provide thumbnail interface easily understood intuitively to the user.  
         [0196]    In the camcorder of FIG. 1, the decoding of an image, audio data, and the like are achieved by the hardware configuration. However, these may be achieved by a software configuration using the processor of the PC of FIG. 6 or the like.  
         [0197]    In such a case, a program code of each software module shown in FIG. 7 achieves the above-described function of the embodiment itself, and the program code itself, and means for supplying the program code to a computer, for example a storage medium storing such a program code, constitute the present invention. For the storage medium storing the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM or the like can be used.  
         [0198]    In addition, not only the above-described function of each embodiment is achieved by executing the program code supplied to the computer, but also the function of each embodiment is achieved by operating the program code on the computer by an operating system (OS) or a combination of other application software programs or the like. These program codes are also within the embodiment of the present invention.  
         [0199]    Furthermore, after the supplied program code is stored in a memory provided in a function expansion board of the computer or a function expansion unit connected to the computer, a CPU or the like provided in the function expansion board or the function expansion unit executes a part or all of actual processing based on the program code and, by this processing, the function of each embodiment is achieved. This case is also within the present invention.  
         [0200]    Many widely different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.