Abstract:
An information processing apparatus and method for inputting encoded information, storing the input information in a detachable information storage device as an information file, reading out, from a program storage device, an information processing program having a function of expanding the information file and reproducing the information using an arbitrary external device, and storing the information processing program in the detachable information storage device in order to transfer the information processing program and information file to the external device.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an information processing apparatus and method of allowing various devices to reproduce information stored in a unique file format. 
     2. Related Background Art 
     Conventionally, a digital still camera which photoelectrically converts sensed optical image data into electrical image data using an image pickup device (photoelectric conversion device) and records the image data in a recording medium (memory) is known. 
     In this digital still camera, since the electrical image data after photoelectric conversion has a large quantity of digital data, the image data is generally compressed and encoded to reduce the data amount, and stored in a memory incorporated in the digital still camera as a compressed image file. 
     For the compressed image file, a compression scheme unique to the digital still camera is often used. For this reason, a compressed image file having a unique file format in place of a general-purpose file format is stored in the memory. 
     Even when JPEG (Joint Photographic coding Experts Group) format, a standard scheme of coding a still image, is used, a file format different from the normal JPEG file format is often employed by, e.g., omitting the header. This is equivalent to the use of a compression scheme that is unique to each digital still camera. 
     As described above, the conventional digital still camera stores the picked up image in the memory as a compressed image file in a unique file format. To reproduce the compressed image file stored in the memory, the decoder side needs to expand the compressed image file using an expansion (decoding) scheme corresponding to the compressed image file. 
     More specifically, unless the compressed image file is expanded by image processing software allowing expansion of a compressed image file in a unique file format, the image cannot be displayed on a screen. For this reason, a picked up image cannot be immediately reproduced. 
     The compressed image file in the unique file format cannot be expanded using general image processing software, so image processing software (image processing program) exclusively used for the digital still camera must be prepared. 
     More specifically, when the image is to be displayed on an external device to reproduce the compressed image file stored in the memory of the digital still camera, the compressed image file cannot be expanded and displayed unless the external device has installed the dedicated image processing software in advance. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in consideration of the above situation, and has as its object to provide an information processing apparatus and method capable of easily expanding an information file in any file format without preparing information processing software dedicated to expanding the information file, thereby reproducing the information. 
     In order to achieve the above object, according to an aspect of the present invention, there are provided an information processing apparatus and method of inputting encoded information, storing the input information in detachable information storage means as an information file, reading out, from program storage means, an information processing program having a function of expanding the information file and reproducing the information using an arbitrary external device, and storing the information processing program in the information storage means. 
     According to another aspect of the present invention, there are provided an information processing apparatus and method of inputting encoded information, storing the input information in detachable information storage means as an information file, reading out, from program storage means, an information processing program having a function of expanding the information file and reproducing the information using an arbitrary external device, and transferring the information processing program to the external device. 
     Other objects, features and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram showing the arrangement of a digital still camera according to the first embodiment of the present invention; 
     FIG. 2 is a view showing an image observation device for expanding a compressed image file obtained by picking up an image with the digital still camera shown in FIG.  1  and displaying the image on a screen; 
     FIG. 3 is a flow chart for explaining operation associated with a memory card on powering the digital still camera  100  in FIG. 1; 
     FIG. 4 is a flow chart for explaining photographing operation in the digital still camera  100  in FIG. 1; 
     FIG. 5 is a flow chart for explaining operation associated with an image display program transfer instruction switch in the digital still camera  100  in FIG. 1; 
     FIG. 6 is a flow chart for explaining the operation of an image observation device  200 ; 
     FIG. 7 is a block diagram showing the arrangement of a digital still camera according to the second embodiment of the present invention; 
     FIG. 8 is a flow chart for explaining operation associated with an image display program selection instruction switch in a digital still camera  600  in FIG. 7; 
     FIG. 9 is a block diagram showing the arrangement of a digital still camera according to the third embodiment of the present invention; 
     FIG. 10 is a flow chart showing operation associated with an image file transfer instruction switch in a digital still camera  700  in FIG. 9; and 
     FIG. 11 is a view showing the hardware circuit arrangement for performing compression encoding processing. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will be described below with reference to the accompanying drawings. 
     The first embodiment will be described. 
     An information processing apparatus according to the present invention is applied to a digital still camera  100  as shown in FIG.  1 . 
     Circuits incorporated in the digital still camera  100  shown in FIG. 1 will be described first. 
     A lens unit  101  including a photographing lens and a lens driving circuit (not shown) forms an image of light from an object on an image pickup device  102  on the output side under the control of a system control unit  110 . 
     The image pickup device  102  is a photoelectric conversion device such as a CCD (Charge Coupled Device) which converts the object image formed by the lens unit  101  into an image signal. 
     An image pickup process unit  103  performs predetermined processing such as gamma (γ) correction for the image signal obtained by the image pickup device  102 . 
     An A/D converter  104  converts the image signal output from the image pickup process unit into a digital signal. 
     A frame memory  105  temporarily stores the image signal from the A/D converter  104  or a compression encoding and decoding unit  108  (to be described later). 
     A D/A converter  106  converts the image signal read out from the frame memory  105  into an analog image signal. 
     An EVF  107  (Electrical View Finder) displays the image signal output from the D/A converter  106 . 
     The compression encoding and decoding unit  108  having a microprocessor or work memory (not shown) for compressing a digital image signal compresses a photographed digital image signal under the control of the system control unit  110  to generate a compressed image file in a file format unique to the digital still camera  100  and outputs the compressed image file to a memory card  109   b  of a memory unit  109 . Also, the compression encoding and decoding unit  108  expands (decodes) the compressed image file and outputs the image signal to the frame memory  105 . 
     The compression encoding and decoding unit  108  can use either a general-purpose compression encoding scheme such as JPEG or a unique compression encoding scheme. 
     When a general-purpose compression encoding scheme such as JPEG is used, a file format different from the JPEG format is employed by, e.g., omitting the header. 
     Image data compression encoding processing will be described with reference to FIG.  11 . 
     FIG. 11 shows a hardware circuit arrangement for performing compression encoding processing. This compression encoding processing can also be performed as software processing, as a matter of course. 
     Input image data is segmented into, e.g., 8×8 pixel blocks, and a DCT transformation circuit  801  performs DCT (Discrete Cosine Transform) transformation for each block. The DCT-transformed image data is quantized by a quantization circuit  802 . The quantization step used by the quantization circuit  802  is controlled such that a predetermined code amount is obtained by variable length coding. 
     The image data quantized by the quantization circuit  802  is subjected to variable length coding by a variable length coding circuit  803 . 
     Referring back to FIG. 1, the memory unit  109  has a memory  109   a  for storing program and the detachable memory card  109   b.  The memory  109   a  for storing program comprises a nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory. 
     The memory  109   a  for storing program stores, in advance, an image display program having a function of expanding a compressed image file obtained by the compression encoding and decoding unit  108  and displaying the image on the screen and a function of converting the compressed image file in a file format unique to the digital still camera in FIG. 1 into a compressed image file in a general-purpose file format, or various processing programs to be executed by the system control unit  110 . 
     The memory card  109   b  is comprised of a rewritable memory such as an SRAM (Static Random Access Memory) or a flash memory. The memory card  109   b  stores the compressed image file in the unique file format, which is obtained from the compression encoding and decoding unit  108 . 
     The system control unit  110  reads out various processing programs stored in the memory  109   a  for storing program in advance, and controls the respective units of the digital still camera to control the entire operation. 
     A switch  111  is a release switch for photographing. The switch  111  has a half-depressed state for the AF (Auto Focus) function or AE (Automatic Exposure) function and a full-depressed state for actually performing a release operation. Operation control based on the state of the switch  111  is performed by the system control unit  110 . More specifically, the system control unit  110  detects the state of the switch  111  and controls the operation of the camera in accordance with the detected switch state to perform the AF function, the AE function, or a release operation. 
     A switch  112  is an instruction switch for transferring the above-described image display program from the memory  109   a  for storing program to the memory card  109   b.  The state of the switch  112  is also detected by the system control unit  110 . The system control unit  110  controls the memory unit  109  in accordance with the state of the switch  112  such that the image display program is transferred to the memory card  109   b.    
     An LED (Light Emitting Diode)  113  is a warning LED. The blinking operation of the LED is controlled by the system control unit  110 . For example, when the memory card  109   b  is not inserted into the memory unit  109 , when the capacity of space area of the memory card  109   b  is smaller than the size of the image display program, or when the capacity of space area of the memory card  109   b  is expected to become smaller than the size of the image display program after the next photographing, i.e., when the image display program cannot be transferred to the memory card  109   b  after the next photographing, the LED  113  is blinked at a corresponding interval to give a warning to the photographer. 
     A compressed image file obtained by the above-described digital still camera  100  is expanded by, e.g., an image observation device  200  shown in FIG.  2  and displayed on the screen. 
     As shown in FIG. 2, the image observation device  200  comprises a personal computer  202 , a memory card insertion unit  203  arranged in the personal computer  202 , and a display  201  connected to the personal computer  202 . 
     The personal computer  202  controls the operation of the entire image observation device  200  and also has a function of reading data stored in the memory card inserted into the memory card insertion unit  203 . 
     The personal computer  202  incorporates a memory  204  storing various processing programs in advance. The processing programs are read and executed by the personal computer  202  to control the operation of the image observation device  200  (to be described later). 
     The image observation device  200  does not have a pre-installed image processing program dedicated to expand a compressed image file in a file format unique to the digital still camera  100  and display the image on the screen. 
     For this reason, the memory card insertion unit  203  can receive the above-described memory card  109   b.  When the memory card  109   b  is inserted into the memory card insertion unit  203 , the compressed image file and the image display program written on the memory card  109   b  are read by the personal computer  202 . The personal computer  202  reads out the image display program stored in the memory card  109   b  inserted into the memory card insertion unit  203  and executes the image display program, thereby expanding the compressed image file in the unique file format, which is stored in the memory card  109   b,  and displaying the image on the display  201 . Detailed of this operation will be described later. 
     The operation of the digital still camera  100  under the control of the system control unit  110  will be described next in detail. 
     The memory  109   a  for storing program stores, in advance, processing programs according to the flow charts shown in FIGS. 3 to  5 . When these processing programs are read out and executed by the system control unit  110 , the digital still camera  100  operates as follows. 
     The memory  109   a  for storing program also stores the above-described image display program in advance. 
     When the digital still camera  100  is powered, the system control unit  110  recognizes it and determines whether the memory unit  109  has the memory card  109   b,  as shown in FIG. 3 (step S 401 ). 
     If YES in step S 401 , the system control unit  110  determines whether a capacity (storage capacity) for storing the image display program is left in the inserted memory card  109   b  (step S 402 ). 
     If YES in step S 402 , the system control unit  110  determines whether a capacity for storing the image display program is left in the memory card  109   b  after the next photographing (step S 403 ). 
     If YES in step S 403 , the system control unit  110  controls the operation of the entire digital still camera  100  such that the digital still camera  100  is set in a state ready to photograph, and ends the processing. 
     If NO in step S 401 , the system control unit  110  blinks the warning LED  113  to help the photographer recognize this state (no memory card state) (step S 404 ) and ends the processing. 
     If NO in step S 402 , the system control unit  110  blinks the warning LED  113  at an interval different from that in step S 404  to help the photographer recognize this state (image display program transfer disabled state) (step S 405 ) and ends the processing. 
     If NO in step S 403 , the system control unit  110  controls the operation of the entire digital still camera  100  such that the digital still camera  100  is temporarily set in a state ready to photograph. When no storage capacity is expected to be left in the memory card  109   b  after the next photographing, the system control unit  110  blinks the warning LED  113  as in step S 405  to help the photographer recognize this state (image display program transfer disabled state) (step S 406 ) and ends the processing. 
     When the digital still camera  100  is ready to photograph, the system control unit  110  determines whether the switch  111  is in a half-depressed state, i.e., a switch  1  state (SW 1  ON state) for performing the AF function or the AE function, as shown in FIG. 4 (step S 411 ). 
     If NO in step S 411 , the system control unit  110  waits until the switch  111  is in the SW 1  ON state. 
     If YES in step S 411 , the system control unit  110  controls the operation of the digital still camera  100  to perform photographing preparation operation such as the AF function or AE function (step S 412 ). 
     When the photographing preparation operation is performed, the system control unit  110  determines whether the switch  111  is in the switch  2  state (SW 2  ON state) for release (step S 413 ). 
     If NO in step S 413 , the system control unit  110  stops control of the photographing preparation operation. The flow returns to step S 411  to wait until the switch  111  is set in the SW 1  ON state again. 
     If YES in step S 413 , the system control unit  110  controls the system control unit  110  to perform actual photographing (step S 414 ). 
     The object image is formed on the image pickup surface of the image pickup device  102  through the lens unit  101 . The optical image data is converted into electrical image data by the image pickup device  102 . The electrical image data is supplied to the compression encoding and decoding unit  108  through the image pickup process unit  103 , the A/D converter  104 , and the frame memory  105 . 
     After processing in step S 414 , the system control unit  110  controls compression processing in the compression encoding and decoding unit  108  (step S 415 ). 
     The compression encoding and decoding unit  108  compresses the digitized image data to generate a compressed image file in a unique file format. 
     After processing in step S 415 , the system control unit  110  controls data transfer from the compression encoding and decoding unit  108  to the memory unit  109  (step S 416 ). 
     The compression encoding and decoding unit  108  writes the generated compressed image file in the memory card  109   b  of the memory unit  109 . 
     After processing in step S 416 , the system control unit  110  performs the same processing as in step S 403 . More specifically, the system control unit  110  determines whether the storage capacity for the image display program is expected to remain in the memory card  109   b  after the next photographing. If it is determined that the storage capacity is expected to remain in the memory card  109   b,  processing is ended. If no storage capacity is expected to remain in the memory card  109   b,  the system control unit  110  blinks the LED  113  when no storage capacity is available after the next photographing, thereby informing the photographer that image display program transfer is impossible, and ends the processing (step S 417 ). 
     When the compressed image file is stored in the memory card  109   b  in the above-described manner, the system control unit  110  determines next whether the switch  112  for transferring the image display program from the memory  109   a  for storing program to the memory card  109   b  is ON, as shown in FIG. 5 (step S 421 ). 
     If NO in step S 421 , the system control unit  110  waits until the switch  112  is turned on. 
     If YES in step S 421 , the system control unit  110  determines whether the memory unit  109  has the memory card  109   b  (step S 422 ). 
     If YES in step S 422 , the system control unit  110  determines whether a capacity (storage capacity) for storing the image display program stored in the memory  109   a  for storing program is left in the inserted memory card  109   b  (step S 423 ). 
     If YES in step S 423 , the system control unit  110  controls data transfer (download) from the memory  109   a  for storing program to the memory card  109   b  (step S 425 ), and ends the processing. 
     With this processing, the image display program stored in the memory  109   a  for storing program is transferred to the memory card  109   b,  and consequently, the memory card  109   b  stores the generated compressed image file and the image display program. 
     If NO in step S 422 , the system control unit  110  blinks the LED  113  as in step S 404  (FIG. 3) to inform the photographer that the memory card is not inserted and ends the processing. 
     If NO in step S 423 , the system control unit  110  blinks the LED  113  as in step S 405  (FIG. 3) to inform the photographer that image display program transfer is impossible (step S 426 ) and ends the processing. 
     In the above-described manner, the compressed image file in the file format unique to the digital still camera  100  and the image display program for expanding and displaying the compressed image file are stored in the memory card  109   b.  The memory card  109   b  is inserted from the memory card insertion unit  203  into the personal computer  202  of the image observation device  200  shown in FIG.  2 . 
     The memory  204  of the personal computer  202  stores a processing program according to the flow chart shown in FIG. 6 in advance. When the personal computer  202  reads out and executes the processing program, the image observation device  200  operates as follows. 
     As shown in FIG. 6, when the memory card  109   b  is inserted into the memory card insertion unit  203  of the personal computer  202  (step S 501 ), the personal computer  202  detects it and reads out the image display program stored in the memory card  109   b  to install the image display program (step S 502 ). 
     Next, the personal computer  202  starts up the image display program installed in step S 502  (step S 503 ), thereby converting the compressed image file stored in the memory card  109   b,  i.e., the compressed image file in the file format unique to the digital still camera  100  into a general-purpose file format (step S 504 ). The personal computer  202  expands the image file and displays it on the display  201  (step S 505 ), and processing is ended. 
     As described above, in the first embodiment, when the photographer operates the switch  112  of the digital still camera  100 , the compressed image file in the file format unique to the digital still camera  100  and the image display program for converting the compressed image file into a general-purpose file format, expanding the image file, and displaying it on the screen are stored in the memory card  109   b.  Therefore, even when the personal computer on which the compressed image file in the unique file format, which is obtained by the digital still camera  100 , is to be displayed does not have a dedicated image display program for expanding the compressed image file and displaying it on the screen, the compressed image file in the unique file format can be easily expanded and displayed on the personal computer by reading out the image display program stored in the memory card  109   b  together with the compressed image file and executing the image display program. 
     If no more capacity of space area for storing the image display program is expected to be left in the memory card  109   b  after the next photographing, the photographer is warned of the state. With this arrangement, the photographer can know in advance whether the capacity of space area for storing the image display program is left in the memory card  109   b.    
     Therefore, independently of the file format of the compressed image file obtained by the digital still camera  100 , the image observation device  200  can easily display the image on the screen, and the operability can also be improved. 
     The personal computer on which the compressed image file obtained by the digital still camera  100  is to be displayed may perform only processing of converting the compressed image file in the unique file format into a general-purpose file format in accordance with the image display program stored in the memory card  109   b.  Processing of expanding the compressed image file in the general-purpose file format, which is obtained upon conversion, and displaying it on the screen may be performed on the basis of a processing program stored in the personal computer in advance. 
     The second embodiment will be described next. 
     An information processing apparatus according to the present invention is applied to a digital still camera  600  shown in FIG.  7 . 
     The digital still camera  600  has the same arrangement as that of the digital still camera  100  in the above-described first embodiment (FIG. 1) except that a program selection switch  601  is added to the arrangement of the digital still camera  100 . 
     The same reference numerals as in the digital still camera  100  shown in FIG. 1 denote the same parts in the digital still camera  600  shown in FIG. 7, and a detailed description thereof will be omitted. 
     With the program selection switch  601 , the digital still camera  600  can select an image display program corresponding to the operating system (OS) of a personal computer  202  of an image observation device  200  shown in FIG. 2 from a plurality of image display programs. 
     A memory  109   a  for storing program of a memory unit  109  stores a plurality of image display programs in advance. 
     The memory  109   a  for storing program of the memory unit  109  also stores a processing program according to the flow chart shown in FIG. 8 in advance. When a system control unit  110  reads out and executes the processing program, the digital still camera  600  operates as follows. 
     For example, the memory  109   a  for storing program of the memory unit  109  stores, in advance, an image display program for an arbitrary OS (to be referred to as an image display program for A hereinafter) and an image display program for an OS different from the arbitrary OS (to be referred to as an image display program for B hereinafter). The OS of the image observation device  200  corresponds to one of the image display program for A and the image display program for B. 
     In the initial state, the image display program for B is selected. That is, unless the program selection switch  601  is depressed (ON), the image display program for B is selected. When the program selection switch  601  is depressed, the image display program for A is selected. 
     First, the system control unit  110  determines whether the program selection switch  601  is ON (step S 701 ). 
     If NO in step S 701 , i.e., if the program selection switch  601  is not depressed, the system control unit  110  detects selection of the image display program for B (step S 703 ). 
     If YES in step S 701 , i.e., if the program selection switch  601  is depressed, the system control unit  110  detects selection of the image display program for A (step S 702 ). 
     The system control unit  110  determines whether a switch  112  for transferring the image display program from the memory  109   a  for storing program to a memory card  109   b  is ON (step S 704 ). 
     If NO in step S 704 , the system control unit  110  waits until the switch  112  is turned on. 
     If YES in step S 704 , the system control unit  110  determines whether the memory unit  109  has the memory card  109   b  (step S 705 ). 
     If YES in step S 705 , the system control unit  110  determines whether the memory card  109   b  has a capacity of space area for storing the image display program for A or B (to be referred to as the selected program hereinafter) selected in step S 701  from the plurality of image display programs stored in the memory  109   a  for storing program (step S 706 ). 
     If YES in step S 706 , the system control unit  110  controls transfer (download) of the selected program from the memory  109   a  for storing program to the memory card  109   b  (step S 708 ), and ends the processing. 
     With this processing, the program selected from the plurality of image display programs stored in the memory  109   a  for storing program is transferred to the memory card  109   b,  and consequently, the memory card  109   b  stores the generated compressed image file and the selected program. 
     If NO in step S 705 , the system control unit  110  blinks an LED  113  as in step S 404  in FIG. 3 to inform the photographer that the memory card is not inserted and ends the processing. 
     If NO in step S 706 , the system control unit  110  blinks the LED  113  as in step S 405  in FIG. 3 to inform the photographer that image display program transfer is impossible and ends the processing (step S 707 ). 
     As described above, in the second embodiment, an image display program corresponding to the operation of the program selection switch  601  is selected from the plurality of image display programs stored in the memory  109   a  for storing program in advance, and stored in the memory card  109   b.  With this arrangement, an image display program corresponding to the OS of the personal computer on which the compressed image file obtained by photographing using the digital still camera  600  is to be displayed can be selected using the program selection switch  601 . Consequently, in addition to the effect of the above-described first embodiment, the compressed image file in the unique file format can be expanded and displayed on the personal computer independently of the OS of the personal computer to be used for screen display. 
     The third embodiment will be described next. 
     FIG. 9 shows an information processing apparatus of the present invention. 
     A digital still camera  700  has the same arrangement as the digital still camera  600  (FIG. 7) in the above-described second embodiment except that a digital interface  701  capable of data communication with an image observation device  200  as shown in FIG. 2 and a switch  702  for instructing to transfer an image file through the digital interface  701  are added to the arrangement of the digital still camera  600 . 
     The same reference numerals as in the digital still camera  600  shown in FIG. 7 denote the same parts in the digital still camera  700  shown in FIG. 9, and a detailed description thereof will be omitted. As the digital interface  701 , USB, IEEE 1394, or the like can be used. 
     In the first and second embodiments, an image file is sent to the image observation device  200  by the memory card  109   b.  However, in the third embodiment, an image file is transferred through the digital interface  701 . 
     The image file transfer processing of the digital still camera  700  of this embodiment will be described below with reference to the flow chart of FIG.  10 . 
     The flow starts upon operating the switch  702 . 
     It is determined whether the switch  702  is connected to the image observation device  200  (step S 801 ). 
     If NO in step S 801 , warning display is made (e.g., an LED  113  is blinked, or a warning is displayed on an EVF  107 ) to inform the user that the image observation device  200  is not connected, and processing is ended (step S 806 ). 
     If YES in step S 801 , the OS of the image observation device  200  is discriminated by communication (step S 802 ). 
     Next, it is determined whether an image display program corresponding to the OS discriminated in step S 802  is stored in a memory  109   a  for storing program (step S 803 ). 
     If NO in step S 803 , warning display is made (e.g., the LED  113  is blinked, or a warning is displayed on the EVF  107 ) to inform the user that the image display program is not stored, and processing is ended (step S 806 ). 
     If YES in step S 803 , the image display program is read out from the memory  109   a  for storing program and transferred to the image observation device  200  through the digital interface  701  (step S 804 ). After this, an image file is read out from the memory card  109   b  and transferred to the image observation device  200  through the digital interface  701 , and processing is ended. 
     According to this embodiment, the image display program corresponding to the transfer destination is automatically recognized and transferred together with the image file, resulting in a high convenience for the user. 
     The object of the present invention can also be achieved when a storage medium such as the memory card  109   b  or the memory  204  storing the program codes of software for realizing the functions of the host and terminal of each of the above-described embodiments is supplied to a system or apparatus, and the computer (or a CPU or an MPU) of the system or apparatus reads out and executes the program codes stored in the storage medium, as a matter of course. 
     In this case, the program codes read out from the storage medium realize the function of each of the above-described embodiments by themselves, and the storage medium storing the program codes constitutes the present invention. 
     As the storage medium for supplying the program codes, a ROM, a RAM, a floppy disk, a hard disk, an optical disk, a magnetooptical disk, a CD-ROM, a CD-R, a magnetic tape, or a nonvolatile memory card such as the memory card  109   b  can be used. 
     The present invention incorporates not only a case wherein the computer executes the readout program codes to realize the function of each of the above embodiments but also a case wherein an OS running on the computer performs part or all of actual processing on the basis of instructions of the program codes to realize the function of each of the above embodiments. 
     The present invention also incorporates a case wherein the program codes read out from the storage medium are written in a memory of a function expansion board inserted into the computer or a function expansion unit connected to the computer, and then, the CPU of the function expansion board or function expansion unit performs part or all of actual processing on the basis of instructions of the program codes to realize the function of each of the above embodiments. 
     The present invention can be applied to an apparatus comprising a single device, as shown in FIG. 1 or  7 , or a system built by a plurality of devices. 
     In the above embodiments, a digital still camera has been exemplified. However, the present invention may be applied to a digital VCR for recording a moving image. The recording medium for recording a compressed image file is not limited to the memory, and various recording media such as a floppy disk, a magnetic tape, an optical card, or a smart medium can be used. 
     In other words, the foregoing description of embodiments has been given for illustrative purposes only and not to be construed as imposing any limitation in every respect. 
     The scope of the invention is, therefore, to be determined solely by the following claims and not limited by the text of the specifications and alterations made within a scope equivalent to the scope of the claims fall within the true spirit and scope of the invention.