Abstract:
An image data processing device includes: a basic image data acquisition device that acquires basic image data; a simplified image data generation device that generates simplified image data corresponding to the basic image data which has been acquired, a size of the simplified image data being smaller than that of the basic image data; a transmission device that transmits at least the basic image data to an external storage device; and an internal storage device that stores the simplified image data without storing the basic image data.

Description:
INCORPORATION BY REFERENCE  
         [0001]    The disclosure of the following priority application is herein incorporated by reference:  
           [0002]    Japanese Patent Application No. 2000-367428, filed Dec. 1, 2000.  
         BACKGROUND OF THE INVENTION  
         [0003]    1. Field of the Invention  
           [0004]    The present invention relates to an image data processing device.  
           [0005]    2. Description of the Related Art  
           [0006]    Image data which has been recorded by an electronic camera is often transferred to and recorded in a data storage device which has a greater recording capacity than the recording medium which is generally provided to the electronic camera. This image data which has been recorded in the data storage device is read out by a personal computer or the like, and is displayed upon a display device which is connected to the personal computer, and/or is printed upon an output device which is connected to the personal computer. If the electronic camera and the data storage device are positioned in places which are remote from one another, and, if no display device is provided upon the data storage device side, in order for the person who is operating the electronic camera to check the images which correspond to the image data which is recorded in the data storage device, it is necessary to preserve the same image data as the image data which have been recorded in the data storage device in the recording medium of the electronic camera as well. Thus the operator of the electronic camera displays the images according to the image data which are recorded on the electronic camera side upon a monitor or the like for display which is provided to the electronic camera, and checks the displayed images.  
           [0007]    This suffers from the problem that it becomes necessary to keep a large recording medium capacity on the electronic camera side in order to preserve the image data which have been recorded in the data storage device in the recording medium internal to the camera as well, and accordingly the size of the camera is increased and its cost mounts up.  
         SUMMARY OF THE INVENTION  
         [0008]    The objective of the present invention is to provide an image data processing device having a capacity which does not store original image data which has been transmitted and stores simplified image data or the like corresponding thereto for management.  
           [0009]    An image data processing device according to the present invention comprises: a basic image data acquisition device that acquires basic image data; a simplified image data generation device that generates simplified image data corresponding to the basic image data which has been acquired, a size of the simplified image data being smaller than that of the basic image data; a transmission device that transmits at least the basic image data to an external storage device; and an internal storage device that stores the simplified image data without storing the basic image data.  
           [0010]    In this image data processing device, it is preferred that: an identifying information generation device that generates identifying information for individually identifying correspondence between the basic image data and the simplified image data is further provided; the signal transmission device transmits at least the basic image data and the identifying information to the external storage device; and the internal storage device stores the simplified image data and the identifying information. In this case, it is preferred that: the basic image data acquisition device, the simplified image data generation device, the transmission device, and the internal storage device perform processing for a plurality of sets of basic image data; a display device that displays a plurality of simplified images corresponding to a plurality of sets of simplified image data is provided; a selection device that selects a single simplified image from the plurality of simplified images which have been displayed upon the display device is provided; a command generation device that generates a delete command for deletion of simplified image data and basic image data corresponding to a simplified image which is selected by the selection device is provided; and the signal transmission device transmits identifying information and a delete command corresponding to the simplified image that has been selected, to the external storage device. Furthermore, it is preferred that: the command generation device generates a protect command for preventing deletion of simplified image data and basic image data corresponding to a simplified image that is selected by the selection device; and the signal transmission device transmits identifying information and a protect command corresponding to the simplified image that has been selected, to the external storage device. Moreover, it is preferred that: the command generation device generates a protection cancel command for canceling prevention of deletion of simplified image data and basic image data corresponding to a simplified image that is selected by the selection device; and the signal transmission device transmits identifying information and a protection cancel command corresponding to the simplified image that has been selected, to the external storage device.  
           [0011]    Also, it is preferred that the identifying information includes inherent information that identifies the image data processing device individually.  
           [0012]    Also, in the above image data processing device, it is preferred that the internal storage device temporarily stores the basic image data and the simplified image data, and deletes only the basic image data after the signal transmission device has transmitted the basic image data to the external storage device.  
           [0013]    Also, it is preferred that the signal transmission device performs a communication with the external storage device by radio.  
           [0014]    Also, it is preferred that: a power supply control device that turns off a supply of power to the image data processing device upon actuation of an actuation member is further provided; and if the actuation member is actuated while the signal transmission device is transmitting the basic image data to the external storage device, the power supply control device turns off the supply of power to the image data processing device after the signal transmission device has completed transmitting of the basic image data.  
           [0015]    Also, it is preferred that: a display device that displays an image related to the basic image data or the simplified image data is further provided; and the display device performs control so as to lower a brightness of display image, when the signal transmission device is transmitting the basic image data to the external storage device.  
           [0016]    An electronic camera according to the present invention comprises: an image capturing device that captures an image of a photographic subject and generates basic image data based thereupon; a simplified image data generation device that generates simplified image data corresponding to the basic image data which has been generated, a size of the simplified data being smaller than that of the basic image data; a transmission device that transmits at least the basic image data to an external storage device; and an internal storage device that stores the simplified image data without storing the basic image data.  
           [0017]    In this electronic camera, it is preferred that a continuous photography control device that performs control for continuous photography is further provided; the internal storage device temporarily stores a plurality of sets of basic image data and a plurality of sets of simplified image data, during continuous photography; the transmission device transmits the plurality of sets of basic image data to the external storage device after the continuous photography has been completed; and the internal storage device deletes a set of basic image data that has been transmitted by the transmission device. In this case, it is preferred that: a display device that displays images related to the basic image data or the simplified image data is further provided; the display device displays a plurality of simplified images corresponding to the plurality of sets of simplified image data; and when the signal transmission device is transmitting a set of basic image data, the display device controls display of the plurality of simplified images so as to be able to identify a simplified image that corresponds to the set of basic image data which is being transmitted.  
           [0018]    An image data storing system according to the present invention that transmits image data from an image data processing device to an external storage device and stores the image data in the external storage device, comprises: a basic image data acquisition device that is provided in the image data processing device and acquires basic image data; a simplified image data generation device that is provided in the image data processing device and generates simplified image data corresponding to the basic image data which has been acquired, a size of the simplified image data being smaller than that of the basic image data; a transmission device that is provided in the image data processing device and transmits at least the basic image data to the external storage device; an internal storage device that is provided in the image data processing device and stores the simplified image data without storing the basic image data; and an image storage device that is provided in the external storage device and stores at least the basic image data which has been transmitted from the image data processing device.  
           [0019]    In this image data storing system, it is preferred that: an identifying information generation device that generates identifying information for individually identifying correspondence between the basic image data and the simplified image data, is further provided; the transmission device of the image data processing device transmits at least the basic image data and the identifying information to the external storage device; the internal storage device of the image data processing device stores the simplified image data and the identifying information; and the image storage device of the external storage device stores at least the basic image data and the identifying information that have been transmitted from the image data processing device.  
           [0020]    In the above image data processing devices, electronic cameras and image data storing systems, it is preferred that the transmission device transmits both the basic image data and the simplified image data to the external storage device.  
           [0021]    Or, in the above image data processing devices, electronic cameras and image data storing systems, it is preferred that the transmission device does not transmit the simplified image data to the external storage device.  
           [0022]    An image data processing method according to the present invention comprises: acquiring basic image data; generating simplified image data corresponding to the basic image data that has been acquired, a size of the simplified image data being smaller than that of the basic image data; transmitting at least the basic image data to an external storage device; and storing the simplified image data without storing the basic image data.  
           [0023]    A computer-readable computer program product contains a program for processing image data, and the program comprises: instructions for acquiring basic image data; instructions for generating simplified image data corresponding to the basic image data that has been acquired, a size of the simplified image data being smaller than that of the basic image data; instructions for transmitting at least the basic image data to an external storage device; and instructions for storing the simplified image data, without storing the basic image data.  
           [0024]    It is preferred that this computer-readable computer program product is a recording medium on which the program is recorded.  
           [0025]    Or, it is preferred that this computer-readable computer program product is a carrier wave in which the program is embodied as a data signal. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]    [0026]FIG. 1 is a figure showing the overall appearance of an image data file transfer system which is a first preferred embodiment of the present invention.  
         [0027]    [0027]FIG. 2 is a block diagram showing the overall structure of an electronic still camera which is a component of the image data file transfer system of FIG. 1.  
         [0028]    [0028]FIG. 3 is a block diagram showing the overall structure of a data storage device which is another component of the image data file transfer system of FIG. 1.  
         [0029]    [0029]FIG. 4 is a flow chart showing the control flow of a photographic procedure performed by the electronic still camera.  
         [0030]    [0030]FIG. 5 is a flow chart for explanation of the control flow of a transfer procedure performed by this electronic still camera.  
         [0031]    [0031]FIG. 6 is a flow chart for explanation of the control flow of an interrupt procedure.  
         [0032]    [0032]FIG. 7 is a flow chart for explanation of the control flow of signal transmission procedures for a delete command, a protect command, and a protection cancel command.  
         [0033]    [0033]FIG. 8 is a flow chart for explanation of the control flow of a procedure which is performed by the data storage device of FIG. 3.  
         [0034]    [0034]FIG. 9 is a flow chart showing the control flow of a photographic procedure performed by the electronic still camera, according to a second preferred embodiment of the present invention.  
         [0035]    [0035]FIG. 10 is a flow chart for explanation of the control flow of a transfer procedure performed by this electronic still camera, according to the second preferred embodiment of the present invention.  
         [0036]    [0036]FIG. 11 is a figure showing an arrangement for providing a program via a recording medium such as a CD-ROM or the like, or via a data signal such as the internet or the like. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0037]    In the following the present invention will be described in terms of several of its preferred embodiments.  
       EMBODIMENT ONE  
       [0038]    [0038]FIG. 1 is a figure showing the overall appearance of an image data file transfer system which is a first preferred embodiment of the present invention. Referring to this figure, an electronic still camera  100  and a data storage device  200  are connected by a communication medium (data transmission medium)  300 . This communication medium  300 , for example, may perform data transfer between the electronic still camera  100  and the data storage device  200  by wireless or radio communication such as Bluetooth or the like. In this first preferred embodiment of the present invention, the electronic still camera  100  is the signal transmission side for the image data, and the data storage device  200  is the signal reception side for the image data. This electronic still camera  100  records images which have been photographed as image data files in a memory internal to said camera  100 , and also transmits these image data files to the data storage device  200  via the communication medium  300 . On the other hand, the data storage device  200  receives these image data files which have been transmitted via the communication medium  300  from the electronic still camera  100 , and records and stores these image data files which it has received in some specific recording device.  
         [0039]    The electronic still camera  100  comprises a power supply switch  111 , a shutter release button  112 , a four way switch  113  which serves as a pointing device, a thumbnail display button  114 , an image data delete button  115 , an image data protect button  116 , and a LCD display section  107 . The power supply switch  111  is an actuation member which performs changeover of the power supply of this electronic still camera  100  between ON and OFF. The shutter release button  112  is an actuation member which starts photographic operation by this electronic still camera  100 . The four way switch  113  is an actuation member which performs pointing actuation in the upwards, downwards, leftwards, and rightwards directions upon a display screen which is being shown upon the LCD display section  107 . The LCD display section  107  can display a single photographed image according to the image data which have been photographed, and alternatively can display an array of thumbnail images. The thumbnail display button  114  is an actuation member which performs changeover of the LCD display section  107  between displaying a single photographed image, and displaying an array of thumbnail images. The actions of the image data delete button  115  and of the image data protect button  116  will be explained hereinafter. It should be understood that the various switches and buttons described above of this electronic still camera  100  may be referred to generally as actuation members  110 .  
         [0040]    The data storage device  200  comprises a power supply switch  211 , a four way switch  212  which serves as a pointing device, a thumbnail display button  213 , an image data delete button  214 , an image data protect button  215 , and an LCD display section  204 . The power supply switch  211  is an actuation member which performs changeover of the power supply of this data storage device  200  between ON and OFF. The four way switch  212  is an actuation member which performs pointing actuation in the upwards, downwards, leftwards, and rightwards directions upon a display screen which is being shown upon the LCD display section  204 . The LCD display section  204  can display a single photographic image according to image data, and alternatively can display an array of thumbnail images. The thumbnail display button  213  is an actuation member which performs changeover of the LCD display section  204  between displaying a single photographed image, and displaying an array of thumbnail images. The actions of the image data delete button  214  and of the image data protect button  215  will be explained hereinafter. It should be understood that the various switches and buttons described above of this data storage device  200  may be referred to generally as actuation members  210 .  
         [0041]    [0041]FIG. 2 is a block diagram showing the overall structure of the electronic still camera  100 . Referring to this figure, the electronic still camera  100  comprises a photographic lens  101 , a CCD  102 , an A/D conversion circuit  103 , an image processor circuit  104 , an internal memory  105 , a CPU circuit  106 , an LCD display section  107 , a data bus  108 , a signal transmission and reception circuit  109 , and the previously described actuation members  110 . The internal memory  105  is a memory card or the like which is detachably fitted to the electronic still camera so as to be removed and replaced at the user&#39;s will. Furthermore, it is acceptable for this electronic still camera to be provided with a semiconductor memory or the like which is fitted internally thereto. The actuation members  110 , as described above, include the shutter release button  112  and the like. When any one of the actuation members  110  is actuated, it sends a signal indicative of the actuation of this switch or button to the CPU circuit  106 . An optical low-pass filter and a color filter (for example, Bayer filter) are disposed on the CCD  102 .  
         [0042]    When the power supply switch Ill is actuated so as to be turned ON, the CPU circuit  106  performs a predetermined ON operation of the electronic still camera  100  to start a control program. The CPU circuit  106  controls the driving of the CCD  102  which is an image capturing device, and controls the operational timing for accumulating electric charges upon this CCD  102 , and for reading out the accumulated electrical charges from this CCD  102 . When an actuation signal is received by the CPU circuit  106  from the shutter release button  112 , the CPU circuit  106  starts photographic action. An image of the subject to be photographed is focused by the photographic lens  101  upon the CCD  102 , and the CCD  102  accumulates signal electric charges corresponding to the brightness of the light from the subject to be photographed which is thus incident. The signal charges which have been thus accumulated in the CCD  102  are discharged according to a timing signal by the CPU circuit  106 , and the resulting signal is converted from an analog image-capture signal to a digital signal by the A/D conversion circuit  103 . This signal which has been converted to digital form is fed to the image processor circuit  104 , and is subjected thereby to predetermined image processing such as contour correction, gamma correction, color temperature adjustment, color space conversion processing, and the like.  
         [0043]    The image data which has been thus subjected to predetermined image processing is further processed into image data for display by the image processor circuit  104 , and is then displayed as the result of photography upon an external monitor such as the LCD display section  107  or the like. The image processor circuit  104  further performs processing upon the image data after it has been thus subjected to the predetermined image processing in order to generate thumbnail image data for thumbnail display, and also performs processing after it has been thus subjected to the predetermined image processing for data compression at a predetermined compression ratio according to the JPEG format. A predetermined file name is appended by the CPU circuit  106  to this image data which has been data compressed, and it is then recorded in the internal memory  105  together with the corresponding thumbnail image data.  
         [0044]    This image data file which has been recorded in the internal memory  105  is transmitted to the signal transmission and reception circuit  109  via the bus  108 . The signal transmission and reception circuit  109  transmits an electromagnetic wave which has been modulated so as to carry this image data signal from an antenna  109 A towards the data storage device  200 .  
         [0045]    [0045]FIG. 3 is a block diagram showing the overall structure of the data storage device  200 . Referring to this figure, the data storage device  200  comprises signal transmission and reception circuit  201 , a memory  202 , an image processor circuit  203 , an LCD display section  204 , a data bus  205 , a CPU circuit  206 , and the previously described actuation members  210 . The actuation members  210 , as described above, include the four way switch  212  and the like. When any one of the actuation members  210  is actuated, it sends a signal indicative of the actuation of this switch or button to the CPU circuit  106 .  
         [0046]    When the power supply switch  211  is actuated so as to be turned ON, the CPU circuit  206  performs a predetermined ON operation of the data storage device  200  to start a control program. An electromagnetic wave signal which has been received via the antenna  201 A is demodulated into an image data signal by the signal transmission and reception circuit  201 , and the image data file which is reconstituted from the image data signal is recorded in the memory  202 . The memory  202  is the main recording device for the data storage device  200 . The image data file which is recorded in the memory  202  is supplied to the image processor circuit  203 , and is processed therein into image data for display. This image data for display is displayed upon an external monitor such as the LCD display section  204  or the like. The image processor circuit  203  also performs decompression processing in order to decompress image data which is in compressed form, according to requirements.  
         [0047]    The flow of a photographic procedure which is performed by the CPU circuit  106  of the electronic still camera  100  will now be explained with reference to the flow chart shown in FIG. 4. When the power supply switch  111  of the electronic still camera  100  is actuated so as to be turned ON, the program whose flow is shown in FIG. 4 is started. First in a step S 1  the CPU circuit  106  performs through image display with the electronic still camera  100 . In this through image display, before shutter release, images are captured by the CCD  102 , and images based upon the image-capture signals which are outputted from the CCD  102  are successively displayed upon the LCD display section  107 . Next in a step S 2  the CPU circuit  106  drives the photographic lens  101  by an A/F device not shown in the figures so as to focus it upon the subject to be photographed, and also performs exposure calculation based upon the brightness of the subject to be photographed which is detected by a photographic subject brightness detection device also not shown in the figures. Next in a step S 3  the CPU circuit  106  decides whether or not the shutter release button  112  has been actuated, and if the shutter release has been actuated then this decision in this step S 3  is YES and the flow of control proceeds to a step S 4 , while if on the other hand the shutter release has not been actuated then this decision in this step S 3  is NO and the flow of control returns to the step S 2 .  
         [0048]    In the step S 4  the CPU circuit  106  starts the photographic processing described above, and then the flow of control proceeds to a step S 5 . In this step S 5  the image data which has been obtained as the result of photography is processed into image data for display by the image processor circuit  104 , and is displayed as a freeze image upon the LCD display section  107 . This freeze image display consists of capturing an image after shutter release actuation by the CCD  102 , and displaying an image based upon the image-capture signal which has been output from the CCD  102  upon the LCD display section  107 . Next in a step S 6  the CPU circuit  106  outputs a command to the image processor circuit  104  for data compression of an original image data according to the JPEG format at a predetermined compression ratio, and then the flow of control proceeds to a next step S 7 .  
         [0049]    In this next step S 7  the CPU circuit  106  records in its internal memory  105  the original image data which has been subjected to compression together with thumbnail image data as a single image data file, for example in the EXIF (Exchangeable Image File Format) file format, and then the flow of control proceeds to a next step S 8 . The image data which has been subjected to compression is termed the “basic image data”, when contrasted with the thumbnail image data. The data size of the thumbnail image data is small by comparison with that of the basic image data, and accordingly the memory capacity which is required for storing it is quite small. In the step S 8  the CPU circuit  106  records an ID in a unique region in the EXIF format file which has been recorded. This ID which is recorded may, for example, include the serial number of this electronic still camera  100 , in order to make it possible for this image data file to be distinguished from other image data files which have been taken using other electronic still cameras.  
         [0050]    Next in a step S 9  the CPU circuit  106  transfers a copy of the image data file in EXIF format which has been recorded in the internal memory  105  to the signal transmission and reception circuit  109 , and then the flow of control proceeds to a next step S 10 . In this step S 10  the CPU circuit  106  performs transfer procedures for this image data by the signal transmission and reception circuit  109 , and when this has been completed the procedure of FIG. 4 is terminated.  
         [0051]    It should be understood that there are at least two methods for producing thumbnail image data. In one method, the original image data is reduced and the reduced image data is generated as the thumbnail image data. In another method, the original image data and the thumbnail image data are produced based on the output of CCD in parallel.  
         [0052]    [0052]FIG. 5 is a flow chart for explanation of the control flow which is executed by the CPU circuit  106  during the transfer procedure of the step S 10  described above. First in a step S 11  the CPU circuit  106  issues a command to the signal transmission and reception circuit  109  for starting signal transmission of the image data file, and then the flow of control continues to a next step S 12 . In this step S 12  the CPU circuit  106  outputs a command to the image processor circuit  104  for lowering the display brightness of the freeze image display which is being displayed upon the LCD display section  107 , and then the flow of control continues to a next step S 13 . In this step S 13  the CPU circuit  106  decides whether or not a receipt completed signal has been received from the data storage device  200 . This receipt completed signal will be explained hereinafter. If the signal transmission and reception circuit  109  has indeed received such a receipt completed signal, then the CPU circuit  106  determines that the result of the decision in the step S 13  is YES, and the flow of control proceeds to the next step S 14 ; while on the other hand, if the signal transmission and reception circuit  109  has not received such a receipt completed signal, then the CPU circuit  106  determines that the result of the decision in the step S 13  is NO, and the flow of control returns to this step S 13  again, in order to repeat the decision procedure.  
         [0053]    Next in this step S 14  the CPU circuit  106  deletes the basic image data from the image data file in EXIF format which is recorded in the internal memory  105 . The result of this is that the data size of the image data file which is recorded in the internal memory  105  becomes smaller. In a next step S 15  the CPU circuit  106  outputs a command to the image processor circuit  104  for returning the display brightness of the freeze image display which is being displayed upon the LCD display section to its original value, and then the procedure of FIG. 5 terminates.  
         [0054]    It should be understood that, although the present invention has been explained above in terms of the transmission of the basic image data and the thumbnail image data together as a single image data file, it would alternatively be acceptable to transmit only the basic image data, without transmitting the thumbnail image data.  
         [0055]    [0055]FIG. 6 is a flow chart for explanation of the control flow of an interrupt procedure which is performed by the CPU circuit  106  when during the above described procedure of FIG. 4 and FIG. 5 an interrupt request is generated for the CPU circuit  106 . Such an interrupt request is generated when an OFF actuation signal is sent from the power supply switch  111 , or by an OFF timer which is set for the CPU circuit  106  in advance, or the like. The CPU circuit  106  changes over to executing the procedure of FIG. 6 when the interrupt request is generated. First in a step S 16  of FIG. 6 the CPU circuit  106  detects whether or not at the time point that the interrupt was generated the steps S 5  through S 10  are being performed, and, if the steps S 5  through S 10  are being performed, then the decision in this step S 16  is YES, and the system waits until the procedure of the step S 10  has terminated. On the other hand, if the steps S 5  through S 10  are not being performed at the time point that the interrupt was generated, then the decision in this step S 16  is NO, and the flow of control proceeds to a step S 17 . In this step S 17  the CPU circuit  106  terminates the control program for the electronic still camera  100  and performs a predetermined power supply OFF procedure, and then this procedure of FIG. 6 is completed.  
         [0056]    The electronic still camera  100  can also be used for transmitting various commands to the data storage device  200 , such as a delete command for deleting an image data file which is stored on the data storage device  200 , a protect command for ensuring that an image data file which is stored on the data storage device  200  cannot be deleted, and a protection cancel command for canceling the above described protection. FIG. 7 is a flow chart for explanation of the control flow of the program which is performed by the CPU circuit  106  when performing signal transmission procedures for the various commands described above. This program of FIG. 7 is started when the thumbnail display button  114  of the electronic still camera  100  is actuated.  
         [0057]    First in a step S 41  of FIG. 7 the CPU circuit  106  reads out in order, from among the image data files in EXIF format which are recorded in the internal memory  105 , those ones of the image data files from which the basic image data has been deleted, and displays an array of images corresponding to the thumbnail image data recorded in these image data files which have been read out upon the LCD display section  107 . By doing this, a thumbnail array according to the image data files which have the same ID as the image data files which are recorded on the data storage device  200  is displayed upon the LCD display section  107 . This displayed array of thumbnail images is produced by the image processor circuit  104  generating data for display, this display data then being displayed by the LCD display section  107 .  
         [0058]    When providing this display of the array of thumbnail images upon the LCD display section  107 , as an initial setting, as shown in FIG. 1, the frame of the one of the thumbnail images at the upper left of the screen is accentuated or highlighted. This thumbnail image which is displayed as accentuated indicates which image data file will be subjected to the actions of an image file delete command, protect command, or protection cancel command. The display of the frame of the thumbnail image as accentuated is controlled by the image processor circuit  104 . The operator can select the thumbnail image which is to be the subject of the above described commands from among the thumbnail images which are displayed by actuating the four way switch  113  upwards, downwards, leftwards and rightwards, as appropriate. For example, if he wishes to select the next thumbnail image rightwards, he actuates the four way switch  113  righwards.  
         [0059]    Next in a step S 42  the CPU circuit  106  detects the actuation signal from the four way switch  113 , and then the flow of control proceeds to a next step S 43 . In this step S 43 , the CPU circuit  106  selects the thumbnail image which is to be the subject of the above described commands based upon the actuation signal from the four way switch  113 . The CPU circuit  106  outputs a command to the image processor circuit  104  to perform accentuated display of the selected thumbnail image, and then the flow of control proceeds to a next step S 44 . In this step S 44  the CPU circuit  106  decides whether or not the image data delete button  115  has been actuated, and if in fact the image data delete button  115  has been actuated, then a YES decision is made in this step S 44 , and the flow of control proceeds to a next step S 45 . On the other hand, if the image data delete button  115  has not been actuated, then a NO decision is made in this step S 44 , and the flow of control is transferred to a step S 48 .  
         [0060]    Next in the step S 45  the CPU circuit  106  transmits a signal to the signal transmission and reception circuit  109  consisting of a delete command signal and the ID which is recorded in the image data file which is to be the subject of this delete command, and then the flow of control proceeds to a step S 46 . In this step S 46  the CPU circuit  106  decides whether or not a delete completed signal has been received from the data storage device  200  by the signal transmission and reception circuit  109 . If indeed a delete completed signal has been received by the signal transmission and reception circuit  109 , then the CPU circuit  106  arrives at a YES decision in this step S 46 , and the flow of control is transferred to a next step S 47 ; while on the other hand, if no delete completed signal has been received by the signal transmission and reception circuit  109 , then the CPU circuit  106  arrives at a NO decision in the step S 46 , and this decision procedure is repeated. This delete completed signal will be explained hereinafter. In the step S 47  the CPU circuit  106 , along with deleting from the internal memory  106  the image data file which corresponds to the thumbnail image which was being displayed as accentuated, in other words the file which corresponds to the ID which has been transmitted along with the delete command, also outputs a command to the image processor circuit  104  to delete the display of the thumbnail image which was being displayed as accentuated. When the procedure of the step S 47  has been completed, the flow of control proceeds to the next step S 48 .  
         [0061]    Next in the step S 48  the CPU circuit  106  decides whether or not the image data protect button  116  has been actuated, and if indeed the image data protect button  116  has been actuated then the result of this decision in the step S 48  is YES and the flow of control proceeds to the next step S 49 . On the other hand, if in fact the image data protect button  116  has not been actuated then the result of this decision in the step S 48  is NO and the flow of control is transferred to a step S 52 . In the step S 49  the CPU circuit  106  transmits a signal to the signal transmission and reception circuit  109  consisting of a protect command signal and the ID which is recorded in the image data file which is to be the subject of this protect command, and then the flow of control proceeds to a step S 50 . In this step S 50  the CPU circuit  106  decides whether or not a protect completed signal has been received from the data storage device  200  by the signal transmission and reception circuit  109 . If indeed a protect completed signal has been received by the signal transmission and reception circuit  109 , then the CPU circuit  106  arrives at a YES decision in this step S 50 , and the flow of control is transferred to a next step S 51 ; while on the other hand, if no protect completed signal has been received by the signal transmission and reception circuit  109 , then the CPU circuit  106  arrives at a NO decision in the step S 50 , and this decision procedure is repeated. This protect completed signal will be explained hereinafter. In the step S 51  the CPU circuit  106  outputs a command to the image processor circuit  104  to superimpose a protection mark over the thumbnail image which is being displayed as accentuated, and then the flow of control proceeds to the next step S 52 .  
         [0062]    Next in the step S 52  the CPU circuit  106  decides whether or not, in the state in which a protection mark is being superimposed over the thumbnail image which is being displayed as accentuated, the image data protection button  116  is again being actuated; and if indeed the image data protection button  116  is being actuated again then the result of this decision in the step S 52  is YES and the flow of control proceeds to a next step S 53 , while if in fact the image data protection button  116  is not being actuated again, then the result of this decision in the step S 52  is NO, and the flow of control is transferred to a step S 56 . In the step S 53  the CPU circuit  106  transmits a signal to the signal transmission and reception circuit  109  consisting of a protection cancel command signal and the ID which is recorded in the image data file which is to be the subject of this protection cancel command, and then the flow of control proceeds to a step S 54 . In this step S 54  the CPU circuit  106  decides whether or not a protection cancel completed signal has been received from the data storage device  200  by the signal transmission and reception circuit  109 . If indeed a protection cancel completed signal has been received by the signal transmission and reception circuit  109 , then the CPU circuit  106  arrives at a YES decision in this step S 54 , and the flow of control is transferred to a next step S 55 ; while on the other hand, if no protection cancel completed signal has been received by the signal transmission and reception circuit  109 , then the CPU circuit  106  arrives at a NO decision in the step S 54 , and this decision procedure is repeated. This protection cancel completed signal will be explained hereinafter. In the step S 55  the CPU circuit  106  outputs a command to the image processor circuit  104  to stop displaying the protection mark over the thumbnail image which is being displayed as accentuated, and then the flow of control proceeds to the next step S 56 .  
         [0063]    Next in the step S 56  the CPU circuit  106  decides whether or not the thumbnail display button  113  is being actuated again, and if indeed the thumbnail display button  113  is being actuated again then the result of this decision in the step S 56  is YES and the flow of control proceeds to a next step S 57 , while on the other hand, if in fact the thumbnail display button  113  is not being actuated again, then the result of this decision in the step S 56  is NO and the flow of control returns to the step S 42 . In the step S 57  the CPU circuit  106  issues a command to the image processor circuit  104  to stop the display of the array of thumbnail images upon the LCD display section  107  according to the thumbnail image data, and then the procedure of FIG. 7 is terminated.  
         [0064]    Next, the procedure which is executed by the data storage device  200  for performing reception and transmission of signals from and to the electronic still camera  100  will be explained. FIG. 8 is a flow chart for explanation of the control flow of this procedure which is executed by the CPU circuit  206  of the data storage device  200 . The program of FIG. 8 is started when the power supply switch  211  of the data storage device  200  is actuated to ON. First in a step S 61  the CPU circuit  206  decides whether or not image data is being received by the signal transmission and reception circuit  201  from the electronic still camera  100 , and if indeed image data is being received then the result of this decision in the step S 61  is YES and the flow of control proceeds to a next step S 62 , while if in fact no image data is being received then the result of this decision in the step S 61  is NO, and the flow of control is transferred to a step S 63 .  
         [0065]    Next in the step S 62 , when the reception of image data by the signal transmission and reception circuit  201  has been completed, the CPU circuit  206  records the image data which has been received as an image data file in the memory  202 . This image data file is a file in EXIF format in which the image data on which a data compression has been performed, the thumbnail image data, and the ID are recorded. Furthermore, the CPU circuit  206  outputs a command to the signal transmission and reception circuit  201  to transmit a receipt completed signal, and then the flow of control proceeds to a next step S 63 . This receipt completed signal is transmitted in order to inform the electronic still camera  100  that the image data has been received. This detection that the receipt of the image data has been completed is, for example, performed by detecting the so called “end of image” mark of the JPEG format data, and by also determining that the file size which is included in the header portion of the JPEG data and the size of the data which has been received agree with one another.  
         [0066]    Next in the step S 63  the CPU circuit  206  decides whether or not a delete command signal has been received from the electronic still camera  100  by the signal transmission and reception circuit  201 , and if indeed a delete command signal has been received then the result of this decision in the step S 63  is YES and the flow of control proceeds to a next step S 64 , while if in fact no delete command signal has been received then the result of this decision in the step S 63  is NO and the flow of control is transferred to a step S 65 . In the step S 64 , the CPU circuit  206  deletes the image data file in the memory  202  which corresponds to the ID which has been received together with the delete command signal by the signal transmission and reception circuit  201 . Furthermore, when the image data file in the memory  202  which corresponds to the ID which has been received has been deleted, the CPU circuit  206  outputs a command to the signal transmission and reception circuit  201  for transmission of a delete completed signal, and then the flow of control continues to the next step S 65 . This delete completed signal is transmitted in order to inform the electronic still camera  100  that the subject image data file has been deleted.  
         [0067]    In this next step S 65  the CPU circuit  206  decides whether or not a protect command signal has been received from the electronic still camera  100  by the signal transmission and reception circuit  201 , and if indeed a protect command signal has been received then the result of this decision in the step S 65  is YES and the flow of control proceeds to a next step S 66 , while if in fact no protect command signal has been received then the result of this decision in the step S 65  is NO and the flow of control is transferred to a step S 67 . In the step S 66 , the CPU circuit  206  prevents and prohibits deletion from the memory  202  of the image data file which corresponds to the ID which has been received together with the protect command signal by the signal transmission and reception circuit  201 . Furthermore, when the deletion of the image data file in the memory  202  which corresponds to the ID which has been received has thus been prevented, the CPU circuit  206  outputs a command to the signal transmission and reception circuit  201  for transmission of a protect completed signal, and then the flow of control continues to the next step S 67 . This protect completed signal is transmitted in order to inform the electronic still camera  100  that deletion of the subject image data file has been prevented.  
         [0068]    In this next step S 67  the CPU circuit  206  decides whether or not a protection cancel command signal has been received from the electronic still camera  100  by the signal transmission and reception circuit  201 , and if indeed a protection cancel command signal has been received then the result of this decision in the step S 67  is YES and the flow of control proceeds to a next step S 68 , while if in fact no protection cancel command signal has been received then the result of this decision in the step S 67  is NO and the flow of control of this procedure of FIG. 8 terminates. In the step S 68 , the CPU circuit  206  cancels the prevention of deletion from the memory  202  of the image data file which corresponds to the ID which has been received together with the protect command signal by the signal transmission and reception circuit  201 . Furthermore, when the prevention of deletion of the image data file in the memory  202  which corresponds to the ID which has been received has thus been cancelled, the CPU circuit  206  outputs a command to the signal transmission and reception circuit  201  for transmission of a protection cancellation completed signal, and then the flow of control of this procedure of FIG. 8 terminates. This protection cancel completed signal is transmitted in order to inform the electronic still camera  100  that prevention of the deletion of the subject image data file has been cancelled.  
         [0069]    The image data file transmission system according to the first preferred embodiment of the present invention described above provides the following operational benefits.  
         [0070]    (1) The electronic still camera  100  is made so as, upon photography, to record thumbnail image data and compressed basic image data as an image data file in its internal memory  105 , so as to transmit a copy of this image data file to the data storage device  200 , and so as to delete the basic image data from the image data file in its internal memory  105  when it receives a receipt completed signal transmitted from the data storage device  200 . Since the basic image data does not remain in the image data file in the internal memory  105 , accordingly it is possible to economize upon the capacity of the internal memory  105  which is used, and it is therefore possible to photograph and to record a greater number of frames. Furthermore, since the basic image data is only deleted after the receipt completed signal transmitted from the data storage device  200  has been received, therefore it cannot happen that the basic image data is mistakenly deleted from the electronic still camera  100  before it has been properly transmitted therefrom to the data storage device  200 . Furthermore, since the thumbnail image data is stored or preserved in the internal memory  105  of the electronic still camera  100 , thereby the photographer is able to display and check the images which have been transmitted to the data storage device  200  upon the LCD display section  107 , even when the data storage device  200  is not nearby.  
         [0071]    (2) It is arranged for the same ID to be recorded in the image data file which is recorded in the internal memory  105  of the electronic still camera  100 , and in the image data file which is transmitted to the data storage device  200 . And, when transmitting a delete command, a protect command, or a protection cancel command for an image data file from the electronic still camera to the data storage device  200 , the ID of the image data file which is to be the subject of the command is also transmitted. As a result, it is possible to perform deletion, protection, or protection cancellation for each image file in the data storage device  200  individually from the electronic still camera  100 .  
         [0072]    (3) Since the above described ID is arranged to include the serial number of the electronic still camera  100 , it cannot duplicate the ID with a different electronic still camera.  
         [0073]    (4) The electronic still camera  100  and the data storage device  200  respectively comprise the signal transmission and reception circuit  109  and the signal transmission and reception circuit  201 , and thereby exchange signals with one another by wireless transmission. Accordingly, the photographer can carry around the electronic still camera  100  by itself in order to perform photography, and the ease of operation is enhanced, by comparison with the case in which the electronic still camera  100  and the data storage device  200  are connected by a data cable.  
         [0074]    (5) Since, if the power supply switch  111  of the electronic still camera  100  is turned OFF partway through the procedure of the step S 5  through the step S 10 , at this time the procedure for turning the power supply OFF is only performed after the transmission of the image data file which has been photographed to the data storage device  200  has been completed (the NO decision in the step S 16 ) , thereby the image data file which has been photographed is prevented from becoming lost without being recorded in the data storage device  200 .  
         [0075]    (6) Since the brightness of the freeze image display which is displayed upon the LCD display section  107  of the electronic still camera  100  is reduced while the image data is being transmitted from the electronic still camera  100  to the data storage device  200  during the steps S 12  through S 15 , thereby the photographer is enabled to check that the image data is being transferred from the fact that the brightness of the display image upon the LCD display section  107  has dropped.  
       EMBODIMENT TWO  
       [0076]    In the first preferred embodiment of the present invention described above, the explanation was made in terms of single frame photography in which one frame at a time is shot. However, in the second preferred embodiment of the present invention, continuous photography or shooting is performed at a predetermined interval while the shutter release button  112  of the electronic still camera  100  is actuated.  
         [0077]    [0077]FIG. 9 is a flow chart showing the control flow of a photographic procedure which is executed by a CPU circuit  106  of an electronic still camera according to a second preferred embodiment of the present invention. It should be understood that, in this figure, to steps which perform procedures identical to ones shown in the flow chart of FIG. 4 for the case of single frame photography, the same step numbers are appended, so that the following explanation will concentrate on the procedures which are different from those shown in FIG. 4. In a step S 5 A of FIG. 9, the image data which has been obtained by photography is processed by the image processor circuit  104  into image data for display, and is displayed as a freeze image upon the LCD display section  107 . At this time, the image processor circuit  104  displays the thumbnail image in array format, in order that the results of continuous photography can be looked at once. Every time a photographic frame is added as a result of continuous photography, the number of thumbnail images which are displayed is increased.  
         [0078]    In a step S 8 B, the CPU circuit  106  checks whether or not the shutter release button  112  is now OFF, and if indeed the shutter release button  112  is now OFF then the result of this decision in the step S 8 B is YES and the flow of control proceeds to a next step S 9 , while if in fact the shutter release button  112  is not yet OFF then the result of this decision in the step S 8 B is NO, and the flow of control returns to the step S 4 .  
         [0079]    In a step S 10 A, the CPU circuit  106  performs a procedure for transferring the image data to the signal transmission and reception circuit  109 , and when the transfer procedure has been completed the procedure of FIG. 9 terminates. Thus, in this step S 10 A, the plurality of image data files which have been obtained by continuous photography are transmitted one at a time from the electronic still camera  100  to the data storage device  200 .  
         [0080]    [0080]FIG. 10 is a flow chart for explanation of the control flow of this transfer procedure performed by the CPU circuit  106  in the step S 10 A. In this figure, to steps which perform procedures identical to ones shown in the flow chart of FIG. 5 for the case of single frame photography, the same step numbers are appended, so that the following explanation will concentrate on the procedures which are different from those shown in FIG. 5.  
         [0081]    In a step S 12 A of FIG. 10, the CPU circuit  106  outputs a command to the image processor circuit  104  for lowering the display brightness of the thumbnail image which corresponds to the image data file which is being transmitted. By doing this, the operator is enabled to know which image data file is being transmitted.  
         [0082]    In a step S 15 A, the CPU circuit  106  outputs a command to the image processor circuit  104  for ceasing to display the thumbnail image whose brightness is currently reduced, and then the flow of control proceeds to a step S 15 B. In this step S 15 B the CPU circuit  106  decides whether or not all of the image data files which have been obtained by continuous photography have been transmitted. If indeed all of these image data files have been transmitted then the result of this decision in the step S 15 B is YES and the procedure of FIG. 10 terminates, while if in fact the some image data files remain to be transmitted, then the result of this decision in the step S 15 B is NO, and the flow of control returns to the step S 11  in order to transmit the next image data file.  
         [0083]    According to this second preferred embodiment of the present invention as described above, it is possible to obtain the same beneficial operational results in the case of continuous photography, as in the case of single frame photography. In particular, with this second preferred embodiment of the present invention, it is possible for the operator easily to be aware of which file is currently being transmitted, and of which files have not yet been transmitted, since an array of thumbnail images which correspond to the image data files which have been obtained as a result of continuous photography is displayed upon the LCD display section  107 , and, while transmitting these image data files one at a time from the electronic still camera  100  to the data storage device  200 , along with reducing the display brightness of that one of these thumbnail images which corresponds to the image data file which is being transmitted, the thumbnail images which correspond to those image data files for which the transmission has been completed are deleted from the display.  
         [0084]    Although by way of example in the above explanation the description was made in terms of the electronic still camera  100  and the data storage device  200  being connected together by wireless communication according to the Bluetooth protocol, they could also be connected by IrDA. Furthermore, it would also be possible to connect together the electronic still camera  100  and the data storage device  200  by a physical cable such as an IEEE-1394 cable, or a USB cable, or a network cable or the like.  
         [0085]    Furthermore, although by way of example in the above explanation the description was made in terms of the electronic still camera  100  and the data storage device  200  being connected together on a one to one basis, it would be possible for the electronic still camera  100  to be provided in plurality, and/or, in the same manner, for the data storage device  200  to be provided in plurality.  
         [0086]    Since the ID which is recorded in each image data file is arranged to include the serial number of the electronic still camera  100 , accordingly it becomes possible to distinguish the image data file from an image data file of a different electronic still camera and there is no danger that an image data file which has been shot by using the different electronic still camera is mistakenly deleted.  
         [0087]    It should be understood that, instead of the ID including the serial number of the electronic still camera  100 , it would alternatively be possible for it to include symbols, characters, or digits identifying the electronic still camera  100  or the photographer.  
         [0088]    Although in the above described preferred embodiments the brightness of the thumbnail image which was displayed upon the LCD display section  107  was reduced while the corresponding image data file was being transmitted from the electronic still camera  100  to the data storage device  200 , it would be acceptable, instead of reducing its brightness, to display this thumbnail image as flashing, or in a different color, or to provide an overlaid display of an icon or text information superimposed upon the thumbnail image display, in order to show that the corresponding image data file was being transmitted.  
         [0089]    Although the above explanation was made in terms of the commands for deleting, protecting, or cancelling the protection of image data files which were recorded in the memory  202  of the data storage device  200  being issued by actuation of the electronic still camera  100 , it would also be possible for these commands to be issued by actuation of the data storage device  200 . In this case, it would be possible for such commands to be issued by actuation of the four way switch  212 , the thumbnail display button  213 , the image data delete button  214 , and the image data protect button  215 .  
         [0090]    Moreover, although the above explanation was made in terms of an image data file transfer system which dealt with still image data which was obtained as a result of photography with an electronic still camera  100 , the present invention could equally well be applied to a data file transfer system which dealt with moving image data.  
         [0091]    Furthermore, although by way of example the explanation was made in terms of the electronic still camera  100 , it should not be considered as being limited to the case of an electronic still camera. Any device which performs image capture using an image capturing element such as a CCD or the like and which accumulates the resulting image data internally, and which transmits this image data to an external device, could equally well be the subject of the present invention. For example, the present invention could be applied to a scanner, a PDA a portable telephone (a cellular phone), a portable personal computer such as a notebook personal computer or the like, or to any device which incorporates an image capturing element.  
         [0092]    Furthermore, the data storage device  200  could be constituted as a personal computer or the like. The personal computer might be connected via an interface cable such as a USB cable or the like to a Bluetooth adapter, in order to perform wireless transmission. A hard disk device or the like of the personal computer would then be used as the memory  202 .  
         [0093]    It should be understood that a program to be executed by a personal computer can be provided via a recording medium such as a CD-ROM, or via a data signal transmission means such as the internet or the like. FIG. 11 is a figure showing such an arrangement. A program is loaded into a personal computer  400  from a CD-ROM  404 . Furthermore, the personal computer  400  is endowed with the function of connection to a communication line  401 . A computer  402  is a server computer which offers the above described program, and which stores the program upon a recording medium such as a hard disk  403  or the like. The communication line  401  may be the internet, a communication line such as a personal computer communication line or the like, or a dedicated communication line. The computer  402  reads out the program from its hard disk  403 , and transmits this program to the personal computer  400  via the communication line  401 . In other words, the program is embodied as a data signal in a carrier wave, and is transmitted via the communication line  401 . In this manner, the program can be provided in the form of a computer-readable computer program product in various forms, such as a recording medium or a data signal impressed upon a carrier wave or the like.  
         [0094]    It should be understood that the data storage device  200  may have a printing function. In this case, the command set outputted from the electronic still camera  100  may include a print command for making the data storage device  200  print out a designated image. Also, the command set outputted from the electronic still camera may include a command for transmitting a copy of the designated basic image data stored in the data storage device  200  to the electronic camera  100 .