CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority from Japanese Patent Application No. 2007-157011 filed Jun. 14, 2007. The entire content of the priority application is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to an image-selecting device and an image-selecting method. More particularly, the present invention relates to an image selecting device and an image selecting method enabling the user to select or deselect a plurality of desired image data from a plurality of images displayed on a display device through simple operations. 
     BACKGROUND 
     There is known an image-selecting device that is provided with a touch panel arranged on a display screen on a display on which a plurality of images are displayed. Then, when a user touches the touch panel by a finger, an image corresponding to the touched position on the touch panel is selected. Japanese Patent Application Publication No. 2005-92386 discloses that an image-selecting device is capable of selecting the image data for the images in a path traced by the finger from a position where the finger touches the touch panel to a position where the finger is removed from the touch panel. 
     SUMMARY 
     However, since the image-selecting device disclosed in Japanese Patent Application Publication No. 2005-92386 selects only the image data for the images in the path traced by the finger on the touch panel, the user must touch each image individually when selecting numerous images, resulting in tedious operations for the user. 
     In view of the foregoing, it is an object of the present invention to provide an image-selecting device and an image-selecting method enabling the user to select or deselect a plurality of desired image data from a plurality of images displayed on a display device through simple operations. 
     To achieve the above and other objects, one aspect of the invention provides an image-selecting device including a storing unit, a displaying unit, a detecting unit, a reading unit, an identification data storing unit, a display controlling unit, an image data identifying unit, and an image data selecting unit. The storing unit stores a plurality of pieces of image data. The displaying unit displays a plurality of images based on a plurality of pieces of image data and has a plurality of display regions for the plurality of images. The detecting unit detects each of the plurality of display regions receiving direct input by an indicator. The reading unit reads the plurality of pieces of image data from the storing unit. The identification data storing unit stores identification data for identifying the plurality of pieces of image data read by the reading unit and assigns a prescribed order to the identification data for the plurality of pieces of image data. The display controlling unit controls the displaying unit to display the plurality of images according to the prescribed order. The image data identifying unit identifies each of the plurality of pieces of image data for the image displayed in the display region detected by the detecting unit. When the image data identifying unit identifies two pieces of image data among the plurality of pieces of image data, the image data selecting unit, selects or deselects image data from one image data of the two pieces of image data to the other image data of the two pieces of image data according to the prescribed order of the identification data. 
     In another aspect of the present invention, there is provided an image-selecting method for an image-selecting device including a storing unit that stores a plurality of pieces of image data, a displaying unit that displays a plurality of images based on the plurality of pieces of image data and has a plurality of display regions for each of the plurality of images, a detecting unit that detects each of the plurality of display regions receiving direct input by an indicator, and an identification data storing unit. The image-selecting method includes: 
     reading the plurality of pieces of image data from the storing unit; 
     storing identification data for identifying the plurality of pieces of image data read in the reading step and assigning a prescribed order to the identification data for the plurality of pieces of image data; 
     controlling the displaying unit to display the plurality of images according to the prescribed order; 
     identifying each of the plurality of pieces of image data for the image displayed in the display region detected by the detecting unit; and 
     selecting or deselecting, when two pieces of image data among the plurality of pieces of image data is identified in the image data identifying step, image data from one image data of the two pieces of image data to the other image data of the two pieces of image data according to the prescribed order of the identification data. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a perspective view showing the external structure of a multifunction peripheral according to a first embodiment of the present invention; 
         FIG. 2  is a block diagram showing the electrical structure of the multifunction peripheral; 
         FIG. 3A  is an explanatory diagram showing a sample relationship between thumbnails of image files displayed on an LCD and their display position numbers; 
         FIG. 3B  is a table showing sample content of a thumbnail list stored in a thumbnail memory area; 
         FIG. 3C  is a table showing sample content of a temporary selection list stored in a temporary selection list memory area; 
         FIG. 4  is a flowchart illustrating steps in a printing process performed on the multifunction peripheral according to the first embodiment; 
         FIG. 5  is a flowchart illustrating steps in a temporary selection process performed on the multifunction peripheral; 
         FIGS. 6A-6D  are explanatory diagrams illustrating a method of selecting image files by touching a touch panel and tracing a path over thumbnails displayed on the LCD; 
         FIGS. 7A-7D  are tables showing the content of the thumbnail list memory area and the temporary selection memory area modified according to the operation in  FIG. 6 ; 
         FIGS. 8A-8D  are explanatory diagrams illustrating a method of changing the selection status flag for image files from “selected” to “unselected” by touching the touch panel and tracing a path over thumbnails displayed on the LCD; 
         FIGS. 9A-9D  are explanatory diagrams illustrating a method of selecting images files by operating a scrolling arrow SA 2  to scroll thumbnails displayed on the LCD; 
         FIGS. 10A-10C  are explanatory diagrams illustrating a method of selecting images files by operating the scrolling arrow SA 2  to scroll thumbnails displayed on the LCD; 
         FIGS. 11A-11D  are explanatory diagrams illustrating a method of selecting images files by operating a scrolling arrow SA 1  to scroll thumbnails displayed on the LCD; 
         FIGS. 12A-12C  are explanatory diagrams illustrating a method of selecting images files by operating the scrolling arrow SA 1  to scroll thumbnails displayed on the LCD; 
         FIGS. 13A-13H  are explanatory diagrams illustrating a method of operating the touch panel when thumbnails are displayed in a single row on the LCD; 
         FIG. 14  is a flowchart illustrating steps in a printing process executed by the multifunction peripheral according to a second embodiment; 
         FIG. 15  is a flowchart illustrating steps in a continuous selection process executed on the multifunction peripheral; and 
         FIG. 16  is an explanatory diagram illustrating a method of selecting image files by individually touching two thumbnails displayed on the LCD. 
     
    
    
     DETAILED DESCRIPTION 
     Next, a first embodiment of the present invention will be described while referring to the accompanying drawings.  FIG. 1  is a perspective view showing the external structure of a multifunction peripheral (hereinafter abbreviated to “MFP”)  1  having an image-selecting device according to the embodiment of the present invention. 
     As shown in  FIG. 1 , the MFP  1  is integrally provided with a printer  21  disposed in a lower section thereof, a scanner  20  disposed in an upper section thereof, and a control panel  6  disposed on the front surface of the scanner  20 . Through these components, the MFP  1  implements various functions, including a printer function, scanner function, and copier function. 
     The scanner  20  includes a document scanning bed (not shown), and a document cover  8  rotatably attached to the document scanning bed via hinges provided on the rear side. 
     The printer  21  functions to record images on printing paper. An opening  5  is formed in the front surface of the MFP  1 , and specifically in the front surface of the printer  21 . A paper tray  3  and a discharge tray  4  are disposed in the opening  5  so as to be completely accommodated therein. The paper tray  3  and discharge tray  4  are arranged in two levels vertically, with the discharge tray  4  disposed above the paper tray  3 . 
     Memory card slots  22  are provided in the front surface of the printer  21  above the opening  5 . The memory card slots  22  accept the insertion of memory cards  22   a  (see  FIG. 2 ). When a memory card  22   a  is inserted into one of the memory card slots  22 , the MFP  1  can store image data scanned by the scanner  20  in the memory card  22   a  as an image file. Some examples of the types of memory cards  22   a  that may be inserted into the memory card slots  22  include CompactFlash (registered trademark), SmartMedia (registered trademark), Memory Stick (registered trademark), SD Card (registered trademark), and xD Card (registered trademark). 
     The connector of a USB interface  23  is also exposed in the front surface of the printer  21  above the opening  5 . The MFP  1  can be connected to a personal computer (hereinafter abbreviated to “PC”) by inserting one end of a USB cable (not shown) into the connector of the USB interface  23  and the other end of the USB cable into the connector of a USB interface provided in the PC, enabling the MFP  1  and the PC to communicate via the USB cable. The method of connecting the PC and the memory card  22   a  to the MFP  1  is not limited to a specific interface (i.e., the USB interface  23  and the memory card slots  22 ), but may be established through another type of interface, such as a parallel interface or network interface, provided in the MFP  1 . Further, if the memory card  22   a  is connected to a card slot or USB interface provided in another device, the MFP  1  may connect to the memory card  22   a  via the above interfaces. 
     The control panel  6  provided on the front of the document cover  8  has a laterally elongated rectangular shape and includes operating keys  15 , an LCD  16 , a touch panel  17 , and a speaker  18  (see  FIG. 2 ). 
     The operating keys  15  allow the user to input commands and data for controlling the MFP  1 . In this embodiment, the operating keys  15  include a Print Image File button  15   a , a Cancel button  15   b , and a Print button  15   c.    
     The touch panel  17  is an input device superposed over the surface of the LCD  16 . The user touches the touch panel  17  to select images and the like displayed on the LCD  16 . For example, when thumbnail images (hereinafter simply referred to as “thumbnails”) are displayed on the LCD  16  and the user touches the touch panel  17 , the touch panel  17  identifies a thumbnail displayed at a display position on the LCD  16  corresponding to the touched position. 
     Here, the touch panel  17  is not limited to any particular position detecting method. For example, the MFP  1  may employ a touch panel using a pressure sensor for detecting pressure by the user&#39;s finger or an indicating device, or a touch panel employing an infrared or electric field sensor detecting proximity of a finger or indicating device. 
     The speaker  18  issues notifications to the user in the form of operating sounds when the user presses the operating keys  15 , or warning sounds when errors occur. With the MFP  1  having the above construction, if the user presses the Print Image File button  15   a  while a memory card  22   a  storing image files is inserted into one of the memory card slots  22  provided in the front surface of the MFP  1 , the MFP  1  reads all image data stored on the memory card  22   a  and displays thumbnails of the image data on the LCD  16 . Here, thumbnails are small images formed by reducing the image files. 
     At this time, the user can touch the touch panel  17  with a finger to indicate a desired thumbnail among thumbnails displayed on the LCD  16 . When the user touches a thumbnail on the LCD  16 , the printer  21  is configured to print the image from the image file corresponding to the touched thumbnail on printing paper. 
     Next, the electrical structure of the MFP  1  will be described with reference to  FIG. 2 .  FIG. 2  is a block diagram showing this electrical structure. As shown in  FIG. 2 , the MFP  1  is primarily configured of a CPU  11 , a ROM  12 , a RAM  13 , the operating keys  15 , the LCD  16 , the touch panel  17 , the speaker  18 , the scanner  20 , the printer  21 , the memory card slots  22 , and the USB interface  23 . The CPU  11 , ROM  12 , and RAM  13  are interconnected via a bus line  26 . 
     Further, the bus line  26  is connected to the operating keys  15 , LCD  16 , touch panel  17 , speaker  18 , scanner  20 , printer  21 , memory card slots  22 , and USB interface  23  via an I/O port  27 . 
     The CPU  11  of the MFP  1  serves to control the various functions of the MFP  1  based on fixed values and programs stored in the ROM  12  and RAM  13  and to control each component of the MFP  1  connected to the I/O port  27  based on various signals exchanged with the USB interface  23 . 
     The ROM  12  is a non-rewritable memory storing control programs and the like executed on the MFP  1 . The image selection program shown in the flowcharts of  FIGS. 4 ,  5 ,  14 , and  15  is also stored in the ROM  12 . 
     The RAM  13  is a nonvolatile rewritable memory for temporarily storing various data when the CPU  11  executes operations of the MFP  1 . The RAM  13  is provided with an image memory area  13   a  storing image files acquired from the memory card  22   a  for images to be printed by the printer  21  on printing paper; a thumbnail list memory area  13   b  storing a thumbnail list including such data as the filenames and reference numbers described later of image files stored in the memory card  22   a ; a temporary selection list memory area  13   c  storing reference numbers of image files identified when the user touches the touch panel  17  in a temporary selection process described later (see  FIG. 5 ) as a temporary selection list; a temporary selection starting position memory area  13   d  storing the reference number of the image file initially identified in the temporary selection process; and a temporary selection ending position memory area  13   e  storing the reference number of the image file last identified in the temporary selection process. 
     Next, the thumbnail list memory area  13   b , temporary selection list memory area  13   c , temporary selection starting position memory area  13   d , and temporary selection ending position memory area  13   e  will be described with reference to  FIGS. 3A-3C . 
       FIG. 3A  is an explanatory diagram conceptually illustrating an example of relationships between thumbnails for image files displayed on the LCD  16  and display position numbers.  FIG. 3B  is a table conceptually illustrating sample content of a thumbnail list stored in the thumbnail list memory area  13   b .  FIG. 3C  is an explanatory diagram conceptually illustrating sample content of a temporary selection list stored in the temporary selection list memory area  13   c.    
     The display position numbers for thumbnails displayed on the LCD  16  will be described with reference to  FIG. 3A . As shown in  FIG. 3A , a total of eighteen thumbnails arranged in three rows and six columns are displayed on the LCD  16 . Scrolling arrows SA 1  and SA 2  are also displayed on the LCD  16  to the right of the thumbnails in a seventh column. 
     To simplify the description of display positions for thumbnails displayed on the LCD  16 , the display position of the thumbnails will be referred to based on a combination of a letter and number, where letters from “A” to “C” indicate the rows of thumbnails (as well as the scrolling arrows SA 1  and SA 2 ) in order from top to bottom and numbers from “1” to “7” indicate the columns of thumbnails (as well as the scrolling arrows SA 1  and SA 2 ) in order from left to right. The combination of letters and numbers will be referred to in the following description as the display position number. For example, “A 1 ” denotes the display position number of the thumbnail displayed in the first row and first column, and “C 6 ” denotes the display position number of the thumbnail displayed in the third row and sixth column. 
     Coordinates for a two-dimensional rectangular shape are established for the LCD  16  and the touch panel  17  superposed over the surface of the LCD  16 , with (0, 0) being the point of origin in the upper left corner and (X, Y) being the ending point in the lower right corner. Each of the display position numbers “A 1 -C 7 ” described above is associated with separate coordinate positions on the LCD  16 . 
     For example, the display position number “A 1 ” is associated with a rectangular display region whose four vertices have coordinates (a, b), (a, d), (c, b), and (c, d). A thumbnail is displayed within this display region. In the same way, each of the other display position numbers “A 2 -C 7 ” is associated with a separate rectangular display region. When the user touches one of the thumbnails (or the scrolling arrow SA 1  or SA 2 ) displayed on the LCD  16 , the user actually touches the touch panel  17  superposed over the LCD  16 . The touch panel  17  detects the coordinates at the touched position, enabling the MFP  1  to identify the image file corresponding to the thumbnail (or scrolling arrow SA 1  or SA 2 ) displayed in a position on the LCD  16  corresponding to the touched coordinates. 
     For example, when the user touches a position on the touch panel  17  within the rectangular region whose four vertices have coordinates (a, b), (a, d), (c, b), and (c, d), the MFP  1  identifies the image file corresponding to the thumbnail displayed at display position number “A 1 ” of the LCD  16 . 
       FIG. 3B  conceptually illustrates sample content of a thumbnail list stored in the thumbnail list memory area  13   b . When the MFP  1  executes a printing process described later with reference to  FIG. 4 , the MFP  1  searches for all image files stored in the memory card  22   a . Subsequently, the MFP  1  creates a thumbnail list that includes the filename, reference number, and other data for each image file found when searching the memory card  22   a  and stores this thumbnail list in the thumbnail list memory area  13   b.    
     As shown in  FIG. 3B , the thumbnail list is configured of sequential reference numbers having no duplication, display position numbers indicating display positions of thumbnails on the LCD  16 , filenames of the image files, and selection status flags indicating whether the image files are selected or unselected. Each row in the thumbnail list corresponds to a single image file. 
     The reference numbers are assigned sequentially to the image files based on an arbitrary order, such as the chronological order of creation dates, the alphabetical order of filenames, or the like. The display position number in the thumbnail list may be set to one of the display position numbers on the LCD  16  described above or to no value. If the display position number is set in the thumbnail list, then a thumbnail of an image file is displayed in the display position of the LCD  16  indicated by the display position number. If no value is set for the display position number in the thumbnail list, a thumbnail of an image file is not displayed on the LCD  16 . 
     Display position numbers in the thumbnail list are assigned to image files sequentially in increasing order of the reference numbers, beginning from an arbitrary reference number in the thumbnail list. The display position numbers are assigned in order from “A 1 ” to “A 6 ”, followed by “B 1 ” to “B 6 ”, followed by “C 1 ” to “C 6 ”. 
     In the thumbnail list shown in  FIG. 3B , the row having reference number “ 1 ” is the starting position for display position numbers and, hence, the display position number in this row is set to “A 1 ”. The display position number in the next row having reference number “ 2 ” is set to “A 2 ”. In this way, the display position numbers are assigned sequentially to rows in the thumbnail list up to display position number “C 6 ” in increasing order of the reference numbers. The case of no display position number being assigned to a row in the thumbnail list occurs when the number of image files stored in the memory card  22   a  exceeds the number of thumbnails that can be displayed on the LCD  16  at one time (eighteen thumbnails in this embodiment). 
     In such cases, the user can display thumbnails not currently displayed on the LCD  16  by touching one of the scrolling arrows SA 1  and SA 2  displayed in display position numbers “A 7 ” and “C 7 ” on the LCD  16 . Thumbnails displayed on the LCD  16  are shifted one row upward when the user touches the scrolling arrow SA 2  displayed at display position number “C 7 ”. In other words, the thumbnails displayed at display position numbers “B 1 -B 6 ” are shifted upward to display position numbers “A 1 -A 6 ”; thumbnails displayed at display position numbers “C 1 -C 6 ” are shifted upward to display position numbers “B 1 -B 6 ”; and new thumbnails are displayed at display position numbers “C 1 -C 6 ”. 
     More specifically, when the user touches the scrolling arrow SA 2  at display position number “C 7 ” on the LCD  16 , first display position numbers “A 1 -C 6 ” are modified in the thumbnail list. That is, display position number “A 1 ” is moved to the row of the thumbnail list with reference number “ 7 ”, display position number “A 2 ” is moved to the row with reference number “ 8 ”, and subsequent display position numbers are moved in the same way, with display position number “C 6 ” being moved to the row having reference number “ 24 ”. Hence, each display position number “A 1 -C 6 ” stored in the thumbnail list is moved down six lines in the list. Subsequently, thumbnails for image files corresponding to the modified display position numbers “A 1 -C 6 ” in the thumbnail list are displayed at display position numbers “A 1 -C 6 ” on the LCD  16 . 
     Further, when the user touches the scrolling arrow SA 1  at display position number “A 7 ”, first display position numbers “A 1 -C 6 ” are modified in the thumbnail list. For example, if the row with reference number “ 13 ” in the thumbnail list is the starting position for display position numbers and, hence, has display position number “A 1 ”, display position number “A 2 ” is set to the next row with reference number “ 14 ”, and subsequent display position numbers are set sequentially in increasing order of reference numbers. When the user touches the scrolling arrow SA 1  at display position number “A 7 ”, display position number “A 1 ” is moved to the row with reference number “ 7 ”, display position number “A 2 ” is moved to the row with reference number “ 8 ”, and subsequent display position numbers are moved similarly, with display position number “C 6 ” being moved to the row having reference number “ 24 ”. Hence, each display position number “A 1 -C 6 ” stored in the thumbnail list is moved up six lines in the list. 
     Hence, thumbnails displayed on the LCD  16  are moved downward one line. That is, the thumbnails displayed at display position numbers “A 1 -A 6 ” are shifted to display position numbers “B 1 -B 6 ”; thumbnails displayed at display position numbers “B 1 -B 6 ” are shifted to display position numbers “C 1 -C 6 ”; and new thumbnails are displayed at display position numbers “A 1 -A 6 ”. 
     The selection status flag indicates whether the image file is “selected” or “unselected.” When the selection status flag is “selected,” the thumbnail of the image file is highlighted on the LCD  16 , as are thumbnails at display position numbers “A 2 ” and “A 3 ” in the example of  FIG. 3A . When the selection status flag is set to “unselected” or is modified from “selected” to “unselected,” the corresponding thumbnail displayed on the LCD  16  is not highlighted, as in the thumbnail at display position number “A 1 ” in the example of  FIG. 3A . In the following description, highlighted thumbnails will be referred to as thumbnails displayed in a selected state, while unhighlighted thumbnails will be referred to as thumbnails displayed in an unselected state. 
       FIG. 3C  is an explanatory diagram conceptually illustrating sample content of the temporary selection list stored in the temporary selection list memory area  13   c . When the user touches the touch panel  17 , the MFP  1  identifies the image file corresponding to the thumbnail displayed on the LCD  16  at a position identical to the coordinate position touched on the touch panel  17 . Further, if the user continues to touch the touch panel  17  with a finger while moving the position of the finger, the MFP  1  identifies the image file corresponding to the thumbnail displayed at the position of the LCD  16  having coordinates corresponding to the coordinate position of the moved finger. 
     The temporary selection starting position memory area  13   d  stores the reference number of the image file initially identified while the user&#39;s finger was touching the touch panel  17 . The temporary selection ending position memory area  13   e  stores the reference number of the image file identified from the coordinates at the new position when the user&#39;s finger moves to a new position while remaining in contact with the touch panel  17 . 
     The temporary selection list memory area  13   c  stores each reference number in the thumbnail list ranging in succession from the reference number stored in the temporary selection starting position memory area  13   d  to the reference number stored in the temporary selection ending position memory area  13   e . Thumbnails for image files corresponding to reference numbers stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in a format different from that for selected and unselected thumbnails, such as the format for the thumbnail at display position number “C 5 ” in the example of  FIG. 3A . In the following description, thumbnails in this format differing from the format for selected and unselected thumbnail displays will be referred to as thumbnails displayed in a temporarily selected state. 
     For example, if the user touches the thumbnail at display position number “C 5 ” on the touch panel  17 , as shown in  FIG. 3A , reference number “ 17 ” of the image file corresponding to the touched thumbnail is stored in both the temporary selection starting position memory area  13   d  and the temporary selection list memory area  13   c . As long as the user continues to touch the touch panel  17 , the thumbnail for the image file corresponding to reference number “ 17 ” stored in the temporary selection list memory area  13   c  is displayed on the LCD  16  in the temporarily selected state. 
     Next, the printing process executed by the CPU  11  of the MFP  1  will be described with reference to  FIG. 4 .  FIG. 4  is a flowchart illustrating steps in this printing process and is executed when the user presses the Print Image File button  15   a  while a memory card  22   a  is inserted into one of the memory card slots  22 . 
     In this printing process, the user can select desired image files from those stored in the memory card  22   a  through simple operations and direct the printer  21  to print images on printing paper based on the selected image files. Accordingly, the MFP  1  can select desired image files from those stored in the memory card  22   a  through simple operations and direct the printer  21  to print images on printing paper based on the selected image files. 
     In S 1  of the printing process, the CPU  11  initializes the thumbnail list memory area  13   b . In S 2  the CPU  11  searches the memory card  22   a  for all image files, creates a thumbnail list based on the image files found in this search, and stores the thumbnail list in the thumbnail list memory area  13   b . When the thumbnail list is created (i.e., when in its initial state), selection status flags for all image files are set to “unselected.” Further, “A 1 ” is set as the display position number in the line having reference number “ 1 ” in the thumbnail list, “A 2 ” is set as the display position number in the line having reference number “ 2 ”, and subsequently display position numbers are set sequentially in increasing order of the reference numbers up to display position number “C 6 ”. 
     In S 3  the CPU  11  displays thumbnails on the LCD  16  for image files corresponding to display position numbers “A 1 -C 6 ” in the thumbnail list stored in the thumbnail list memory area  13   b  and sets each thumbnail to the selected state or the unselected state based on the selection status flag for the corresponding image file. 
     In S 4  the CPU  11  determines whether the position of the user&#39;s fingers touching the touch panel  17  is a display position on the LCD  16  for displaying a thumbnail. If the position of the user&#39;s finger on the touch panel  17  is a display position for a thumbnail (S 4 : YES), the CPU  11  executes a temporary selection process in S 5 . However, if the position of the user&#39;s finger does not correspond to a display position for a thumbnail (S 4 : NO), the CPU  11  skips S 5 -S 8  and advances to S 9 . 
     Here, the temporary selection process of S 5  will be described with reference to  FIG. 5 .  FIG. 5  is a flowchart illustrating steps in the temporary selection process and serves to determine reference numbers of image files whose selection status flags have changed in the thumbnail list and the range of reference numbers for image files whose selection status flags have changed based on the position of the user&#39;s finger on the touch panel  17 . During the period that the CPU  11  is executing the temporary selection process, thumbnails for image files corresponding to reference numbers stored in the temporary selection list memory area  13   c  are set to the temporarily selected state on the LCD  16 . 
     In S 21  at the beginning of the temporary selection process, the CPU  11  initializes the temporary selection list memory area  13   c . In S 22  the CPU  11  identifies the display position number of the thumbnail displayed at the display position on the LCD  16  identical to the position of the user&#39;s finger on the touch panel  17  and stores the reference number of the image file corresponding to the identified display position number in both the temporary selection starting position memory area  13   d  and the temporary selection list memory area  13   c . In S 23  the CPU  11  sets only thumbnail of image file corresponding to the reference number stored in the temporary selection list memory area  13   c  to the temporarily selected state on the LCD  16 . 
     In S 24  the CPU  11  determines whether the user&#39;s fingers has separated from the touch panel  17 . If the user&#39;s finger has separated from the touch panel  17  (S 24 : YES), the CPU  11  ends the temporary selection process and advances to S 6  in  FIG. 4 . 
     However, if the user&#39;s finger is still touching the touch panel  17  (S 24 : NO), in S 25  the CPU  11  identifies the display position number of the thumbnail, or scrolling arrow SA 1  or SA 2  displayed at the display position on the LCD  16  corresponding to the position of the user&#39;s finger on the touch panel  17 . 
     In S 26  the CPU  11  determines whether the position of the user&#39;s finger on the touch panel  17  has moved to the display position of a different thumbnail. If the user&#39;s finger has moved to the display position of a different thumbnail (S 26 : YES), then in S 27  the CPU  11  stores the reference number of the image file corresponding to the display position number identified in S 25  in the temporary selection ending position memory area  13   e.    
     In S 28  the CPU  11  stores all reference numbers in sequence from the reference number stored in the temporary selection starting position memory area  13   d  to the reference number stored in the temporary selection ending position memory area  13   e  in the temporary selection list memory area  13   c , and subsequently returns to S 23  to repeat the process in S 23 -S 28  described above. However, if the CPU  11  determines in S 26  that the position of the user&#39;s finger touching the touch panel  17  has not moved to the display position of a different thumbnail (S 26 : NO), then the CPU  11  skips S 27 -S 28  and advances to S 29 . 
     In S 29  the CPU  11  determines whether the position of the user&#39;s finger on the touch panel  17  has moved to a display position for one of the scrolling arrows SA 1  and SA 2 . If the position of the user&#39;s finger has not moved to a display position for one of the scrolling arrows SA 1  and SA 2  (S 29 : NO), then the CPU  11  repeats the process in S 23 -S 29  described above. However, if the position of the user&#39;s finger has moved to a display position for one of the scrolling arrows SA 1  and SA 2  (S 29 : YES), in S 30  the CPU  11  updates the display position numbers in the thumbnail list based on the display position number for the scrolling arrow SA 1  or SA 2  displayed on a position of the LCD  16  corresponding to the finger touching the touch panel  17 . 
     In S 31  the CPU  11  displays thumbnails of image files corresponding to the display position numbers in the thumbnail list on the LCD  16  and sets each thumbnail to a selected state or an unselected state based on the selection status flag of the corresponding image file. Next, in S 32  the CPU  11  stores the reference number of the image file corresponding to display position number “C 6 ” in the thumbnail list in the temporary selection ending position memory area  13   e  if the position of the user&#39;s finger on the touch panel  17  corresponds to the display position of the scrolling arrow SA 2  having display position number “C 7 ”, and stores the reference number of the image file corresponding to display position number “A 6 ” in the temporary selection ending position memory area  13   e  if the position of the user&#39;s finger corresponds to the display position of the scrolling arrow SA 1  having display position number “A 7 ”. 
     In S 33  the CPU  11  stores in the temporary selection list memory area  13   c  all reference numbers in a continuous range from the reference number stored in the temporary selection starting position memory area  13   d  to the reference number stored in the temporary selection ending position memory area  13   e . In S 34  the CPU  11  determines whether the position of the user&#39;s finger on the touch panel  17  has moved outside the scrolling arrow SA 1  or SA 2 . If the user&#39;s finger continues to touch the display position of the scrolling arrow SA 1  or SA 2  (S 34 : NO), in S 35  the CPU  11  waits for a prescribed time (2 seconds, for example) and returns to S 30  to repeat the process in S 30 -S 35  described above. 
     However, if the user&#39;s finger has moved outside the display positions of the scrolling arrows SA 1  and SA 2  (S 34 : YES), then the CPU  11  returns to S 23  and repeats the process in S 23 -S 34  described above. 
     Through the temporary selection process of S 5  shown in  FIG. 5 , the MFP  1  can specify either a reference number for an image file whose selection status flag has changed in the thumbnail list, or a range of reference numbers for image files whose selection status flags have changed, based on the position of the user&#39;s finger on the touch panel  17 . Further, while executing the temporary selection process, the MFP  1  can display thumbnails of image files corresponding to reference numbers stored in the temporary selection list memory area  13   c  in a temporarily selected state on the LCD  16 . After completing the temporary selection process of S 5 , the CPU  11  returns to  FIG. 4  and advances to S 6 . 
     In S 6  of  FIG. 4  the CPU  11  determines whether the selection status flag for the image file corresponding to the reference number stored in the temporary selection starting position memory area  13   d  is set to “unselected.” If the selection status flag for this image file is “unselected” (S 6 : YES), then in S 7  the CPU  11  changes selection status flags for all image files corresponding to reference numbers stored in the temporary selection list memory area  13   c  to “selected” in the thumbnail list stored in the thumbnail list memory area  13   b . However, if the selection status flag for the image file corresponding to the reference number stored in the temporary selection starting position memory area  13   d  is set to “selected” (S 6 : NO), in S 8  the CPU  11  changes the selection status flags for all image files corresponding to reference numbers stored in the temporary selection list memory area  13   c  to “unselected” in the thumbnail list stored in the thumbnail list memory area  13   b . Subsequently, the CPU  11  returns to S 3  and repeats the process in S 3 -S 8  described above. 
     If the CPU  11  determines in S 4  that the position of the user&#39;s finger on the touch panel  17  does not correspond to a display position of a thumbnail on the LCD  16  (S 4 : NO), then the CPU  11  skips S 5 -S 8  and advances to S 9 . In S 9  the CPU  11  determines whether the position of the user&#39;s finger on the touch panel  17  corresponds to a display position for the scrolling arrow SA 1  or SA 2 . 
     If the position of the user&#39;s finger does correspond to a display position for either the scrolling arrow SA 1  or SA 2  (S 9 : YES), in S 10  the CPU  11  updates the display position numbers in the thumbnail list based on the display position number of the scrolling arrow SA 1  or SA 2  displayed at the position of the user&#39;s finger. However, if the user&#39;s finger is not at a display position of the scrolling arrow SA 1  or SA 2  (S 9 : NO), the CPU  11  skips S 10  and advances to S 11 . 
     In S 11  the CPU  11  determines whether the Cancel button  15   b  has been pressed. If the Cancel button  15   b  has been pressed (S 11 : YES), the CPU  11  ends the printing process. However, if the Cancel button  15   b  has not been pressed (S 11 : NO), in S 12  the CPU  11  determines whether the Print button  15   c  has been pressed. 
     If the CPU  11  determines that the Print button  15   c  has been pressed (S 12 : YES), in S 13  the CPU  11  reads image files having a selection status flag set to “selected” in the thumbnail list stored in the thumbnail list memory area  13   b  from the memory card  22   a , stores these image files in the image memory area  13   a , controls the printer  21  to print an image of each file on printing paper, and subsequently ends the printing process. However, if the Print button  15   c  has not been pressed (S 12 : NO), the CPU  11  returns to S 3  and repeats the process in S 3 -S 12  described above. 
     Through the printing process of  FIG. 4  described above, the user can specify two image files through a simple operation of sliding a finger over thumbnails displayed on the LCD  16  and then lifting the finger therefrom. Specifically, the image file corresponding to the thumbnail first touched by the user and the image file corresponding to the thumbnail last touched by the user are set as the two image files, and all image files with reference numbers ranging in sequence from the reference number for the image file corresponding to the first touched thumbnail to the reference number for the image file corresponding to the last touched thumbnail are specified. All image files within this specified range are either selected or deselected. 
     Specifically, if the selection status flag of the image file corresponding to the first touched thumbnail is “unselected,” selection status flags for all image files within the range specified by sliding a finger over the thumbnails are set to “selected.” If the selection status flag for the image file corresponding to the first touched thumbnail is “selected” initially, then selection status flags for all image files within the specified range are set to “unselected.” In other words, the selection status flags for all image files within the range specified by the user&#39;s sliding finger are set based on the selection status flag for the image file corresponding to the first touched thumbnail, enabling the user to perform the process through a simple, easy-to-understand operation. 
     Next, a method of operating the touch panel  17  will be described with reference to  FIGS. 6A-13H . First, a method of selecting image files in which the user traces a path over thumbnails while touching the touch panel  17  will be described with reference to  FIGS. 6A-7D . 
       FIGS. 6A-6D  are explanatory diagrams illustrating a method in which the user selects image files by touching the touch panel  17  with a finger and tracing the finger over thumbnails.  FIGS. 7A-7D  conceptually illustrate the content of the thumbnail list memory area  13   b  and temporary selection list memory area  13   c  that changes according to the operation shown in  FIGS. 6A-6D . 
     When the user presses the Print Image File button  15   a  of the operating keys  15  while a memory card  22   a  storing image files is inserted into one of the memory card slots  22 , thumbnails for the image files stored in the memory card  22   a  are displayed on the LCD  16 . In this description, it will be assumed that the thumbnail list memory area  13   b  stores the thumbnail list shown in  FIG. 7A . Accordingly, thumbnails for image files corresponding to display position numbers “A 1 -C 6 ” in the thumbnail list are displayed at display position numbers “A 1 -C 6 ” on the LCD  16 . Since the selection status flags in the thumbnail list are all set to “unselected” in  FIG. 7A , the thumbnails are all displayed on the LCD  16  in an unselected state. 
     At this time the user touches the thumbnail corresponding to display position number “A 2 ”, as shown in  FIG. 6A . Accordingly, the reference number “ 2 ” in the line of the thumbnail list having display position number “A 2 ” is stored in both the temporary selection starting position memory area  13   d  and the temporary selection list memory area  13   c . The thumbnail for the image file corresponding to reference number “ 2 ” stored in the temporary selection list memory area  13   c  is displayed on the LCD  16  in a temporarily selected state, as shown in  FIG. 6A . 
     Next, the user traces a path to the thumbnail having display position number “B 5 ” while the finger remains in contact with the touch panel  17 . At this time, reference number “ 11 ” for the line having display position number “B 5 ” in the thumbnail list is stored in the temporary selection ending position memory area  13   e . Consequently, reference numbers “ 2 - 11 ” from reference number “ 2 ” stored in the temporary selection starting position memory area  13   d  to reference number “ 11 ” stored in the temporary selection ending position memory area  13   e  are all stored in the temporary selection list memory area  13   c , as shown in FIG.  7 B. Therefore, thumbnails for image files corresponding to reference numbers “ 2 - 11 ” stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in a temporarily selected state, as shown in  FIG. 6B . Since the selected thumbnails remain displayed on the LCD  16  in the temporarily selected state while the user&#39;s finger remains in contact with the touch panel  17 , the user can easily visualize which image files are selected. 
     If the user subsequently traces a path to the thumbnail at display position number “B 3 ” while keeping the finger in contact with the touch panel  17 , as shown in  FIG. 6C , reference number “ 9 ” for the line having display position number “B 3 ” in the thumbnail list is stored in the temporary selection ending position memory area  13   e.    
     Accordingly, the range of reference numbers “ 2 - 9 ” from the reference number “ 2 ” stored in the temporary selection starting position memory area  13   d  to the reference number “ 9 ” stored in the temporary selection ending position memory area  13   e  are stored in the temporary selection list memory area  13   c , as shown in  FIG. 7C . Hence, thumbnails for image files corresponding to reference numbers “ 2 - 9 ” stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 6C . 
     The thumbnails of image files corresponding to reference numbers not stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  based on the selection status flags in the thumbnail list. Therefore, the user can modify the range of selected image files any number of times by moving the position of the user&#39;s finger while the finger remains in contact with the touch panel  17 . Since only thumbnails for selected image files are displayed in the temporarily selected state on the LCD  16 , the user can easily visualize which image files are selected. 
     If the user lifts the finger from the touch panel  17  at this time, all selection status flags for lines having reference numbers “ 2 - 9 ” in the temporary selection list memory area  13   c  are set to “selected” in the thumbnail list, as shown in  FIG. 7D , because the selection status flag is set to “unselected” in the line having reference number “ 2 ” stored in the temporary selection starting position memory area  13   d . Consequently, thumbnails for image files having a selection status flag set to “selected” are displayed on the LCD  16  in the selected state, as shown in  FIG. 6D . 
     In the first embodiment described above, the user can select (or deselect) image files for reference numbers ranging sequentially from the reference number of the image file corresponding to the first touched thumbnail to the reference number of the image file corresponding to the last touched thumbnail by performing a simple operation (single operation) of tracing the user&#39;s finger over a plurality of thumbnails displayed on the LCD  16 . If the user wishes to select (or deselect) three or more image files, the user need only touch two thumbnails displayed on the LCD  16  since three or more image files corresponding to all reference numbers between reference numbers of the image files corresponding to the two touched thumbnails (including the reference numbers for these two image files) are selected in order of reference number. Hence, the user need not touch all thumbnails corresponding to the three or more image files being selected (or deselected). 
     Conventionally, thumbnails displayed within rectangular regions on the LCD  16  were identified when a corresponding rectangular region on the touch panel  17  was indicated, and the image file corresponding to the identified thumbnail was selected (or deselected). 
     Accordingly, when selecting (or deselecting) a plurality of thumbnails, the user had to indicate at least two regions on the touch panel  17  when the thumbnails that the user wished to select (or deselect) started or ended in the middle of a row. However, in the first embodiment described above, the user can select (or deselect) image files having reference numbers ranging sequentially from the reference number for the image file corresponding to the first touched thumbnail to the reference number for the image file corresponding to the last touched thumbnail, enabling the user to select (or deselect) a plurality of image files through a simple operation. The user can also adjust the selected (or deselected) range of images any number of times while the user&#39;s finger remains touching the touch panel  17 , making this technique more user-friendly. 
     The MFP  1  of the first embodiment described above is particularly convenient when selecting (or deselecting) thumbnails displayed successively along the direction of rows. For example, when the user wishes to select image files for thumbnails displayed at display position numbers “A 1 -C 1 ”, the user need only touch the thumbnail at display position number “A 1 ” and slide the finger downward over the touch panel  17  to the thumbnail at display position number “C 1 ”, a simple operation in which the user slides the finger a short distance to select all image files between display position numbers “A 1 ” and “C 1 ”. 
     Next, a method of deselecting image files whose selection status flags are set to “selected” will be described with reference to  FIGS. 8A-8D . In this method, the user traces a path over thumbnails with the user&#39;s finger in contact with the touch panel  17 . 
       FIGS. 8A-8D  are explanatory diagrams conceptually illustrating the method of changing the “selected” setting of the selection status flag to “unselected” for image files corresponding to thumbnails displayed on the LCD  16  by sliding a finger over these thumbnails on the touch panel  17 . As shown in  FIG. 8A , the selection status flags for image files corresponding to thumbnails displayed at display position numbers “A 2 -B 3 ” are set to “selected,” resulting in these thumbnails being displayed in the selected state on the LCD  16 . 
     If the user touches the touch panel  17  at a position corresponding to the thumbnail at display position number “A 2 ” at this time, as shown in  FIG. 8B , reference number “ 2 ” in the line of the thumbnail list having display position number “A 2 ” is stored in both the temporary selection starting position memory area  13   d  and the temporary selection list memory area  13   c . Consequently, the thumbnail for the image file corresponding to reference number “ 2 ” stored in the temporary selection list memory area  13   c  is displayed in a temporarily selected state on the LCD  16 , as shown in  FIG. 8B . 
     Next, while a keeping the finger in contact with the touch panel  17 , the user slides the finger to the thumbnail at display position number “A 4 ”, as shown in  FIG. 8C . At this time, reference number “ 4 ” in the line of the thumbnail list having display position number “A 4 ” is stored in the temporary selection ending position memory area  13   e . Next, all reference numbers “ 2 - 4 ” ranging in succession from reference number “ 2 ” stored in the temporary selection starting position memory area  13   d  to reference number “ 4 ” stored in the temporary selection ending position memory area  13   e  are stored in the temporary selection list memory area  13   c . Consequently, thumbnails for image files corresponding to reference numbers “ 2 - 4 ” stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 8C . 
     If the user lifts the finger from the touch panel  17  at this time, all selection status flags for reference numbers “ 2 - 4 ” stored in the temporary selection list memory area  13   c  are set to “unselected” in the thumbnail list since the selection status flag for reference number “ 2 ” stored in the temporary selection starting position memory area  13   d  is “selected” in the thumbnail list. Consequently, the thumbnails for these image files having selection status flags now set to “unselected” are displayed on the LCD  16  in the unselected state, as shown in  FIG. 8D . 
     Next, a method of selecting image files when the number of image files stored in the memory card  22   a  exceeds the number of thumbnails that can be displayed on the LCD  16  (eighteen thumbnails in this embodiment) will be described with reference to  FIGS. 9A-12C . In this method, the user operates the scrolling arrows SA 1  and SA 2  to scroll thumbnails displayed on the LCD  16 . 
       FIGS. 9A-10C  are explanatory diagrams illustrating the method of selecting image files by operating the scrolling arrow SA 2  to scroll thumbnails displayed on the LCD  16 . 
     In the following example, it will be assumed that 48 image files are recorded in the thumbnail list stored in the thumbnail list memory area  13   b , each image file being assigned a unique reference number from “ 1 ” to “ 48 ” and the selection status flags for all image files being set to “unselected.” Accordingly, all thumbnails displayed on the LCD  16  are in an unselected state. 
     In the thumbnail list, the line having reference number “ 1 ” is the starting position for display position numbers and, hence, the display position number in this line is set to “A 1 ”, while the display position number in the next row having reference number “ 2 ” is set to “A 2 ”. In this way, the display position numbers are assigned sequentially to lines in the thumbnail list up to display position number “C 6 ” in increasing order of the reference numbers. 
     If the user touches the thumbnail at display position number “A 2 ” at this time, as shown in  FIG. 9A , reference number “ 2 ” in the line of the thumbnail list having display position number “A 2 ” is stored in both the temporary selection starting position memory area  13   d  and the temporary selection list memory area  13   c . Consequently, the thumbnail for the image file corresponding to reference number “ 2 ” stored in the temporary selection list memory area  13   c  is displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 9A . 
     In this example, the user next slides the user&#39;s finger to the thumbnail at display position number “B 5 ” while keeping the finger in contact with the touch panel  17 , as shown in  FIG. 9B . At this time, reference number “ 11 ” in the line of the thumbnail list having display position number “B 5 ” is stored in the temporary selection ending position memory area  13   e , and all reference numbers “ 2 - 11 ” ranging in succession from reference number “ 2 ” stored in the temporary selection starting position memory area  13   d  to reference number “ 11 ” stored in the temporary selection ending position memory area  13   e  are stored in the temporary selection list memory area  13   c . Consequently, thumbnails for image files corresponding to reference numbers “ 2 - 11 ” stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 9B . 
     Next, the user slides the finger through the thumbnail at display position number “C 6 ” to the scrolling arrow SA 2  at display position number “C 7 ” while the finger remains in contact with the touch panel  17 , as illustrated in  FIGS. 9B and 9C . Since the user&#39;s finger first contacted the thumbnail at display position number “C 6 ”, reference number “ 18 ” in the thumbnail list having display position number “C 6 ” is stored in the temporary selection ending position memory area  13   e  and all reference numbers “ 2 - 18 ” ranging in succession from reference number “ 2 ” stored in the temporary selection starting position memory area  13   d  to reference number “ 18 ” stored in the temporary selection ending position memory area  13   e  are stored in the temporary selection list memory area  13   c . Consequently, thumbnails for image files corresponding to reference numbers “ 2 - 18 ” stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in a temporarily selected state, as shown in  FIG. 9C . 
     Next, when the position of the user&#39;s finger has moved to the scrolling arrow SA 2  at display position number “C 7 ”, the thumbnails are scrolled in the LCD  16 . Specifically, all thumbnails displayed in the second row of the LCD  16  are moved to the first row, all thumbnails in the third row are moved to the second row, and new thumbnails are displayed in the third row. 
     More specifically, when the user&#39;s finger touches the scrolling arrow SA 2  at display position number “C 7 ” on the LCD  16 , first display position numbers “A 1 -C 6 ” are modified in the thumbnail list. That is, display position number “A 1 ” is moved to the line of the thumbnail list with reference number “ 7 ”, display position number “A 2 ” is moved to the line with reference number “ 8 ”, and subsequent display position numbers are moved in the same way, with display position number “C 6 ” being moved to the line having reference number “ 24 ”. Hence, each display position number “A 1 -C 6 ” stored in the thumbnail list is moved down six lines in the list. 
     Next, thumbnails for image files corresponding to the modified display position numbers “A 1 -C 6 ” in the thumbnail list are displayed at display position numbers “A 1 -C 6 ” on the LCD  16 , and the reference number for the image file corresponding to the new thumbnail displayed at display position number “C 6 ” on the LCD  16  is stored in the temporary selection ending position memory area  13   e . Next, all reference numbers ranging in succession from the reference number stored in the temporary selection starting position memory area  13   d  to the reference number stored in the temporary selection ending position memory area  13   e  are stored in the temporary selection list memory area  13   c . Consequently, thumbnails for image files corresponding to the reference numbers stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in the temporarily selected state. The above process is repeated at prescribed intervals (every 2 seconds, for example) while the user&#39;s finger remains in contact with the scrolling arrow SA 2 , thereby continuing to scroll the thumbnails displayed on the LCD  16 . 
       FIG. 9D  shows the state of thumbnails displayed on the LCD  16  after the thumbnails were scrolled six times from the state shown in  FIG. 9C . That is, display position number “A 1 ” has been moved to the line in the thumbnail list having reference number “ 31 ”, display position number “A 2 ” has been moved to the line having reference number “ 32 ”, and subsequent display position numbers have been moved in the same way, with display position number “C 6 ” being moved to the line with reference number “ 48 ”. 
     Therefore, reference number “ 48 ” is stored in the temporary selection ending position memory area  13   e , and all reference numbers “ 2 - 48 ” ranging in succession from reference number “ 2 ” stored in the temporary selection starting position memory area  13   d  to reference number “ 48 ” stored in the temporary selection ending position memory area  13   e  have been stored in the temporary selection list memory area  13   c . Consequently, thumbnails for image files corresponding to reference numbers “ 2 - 48 ” stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 9D . 
     If the user further slides the finger to the thumbnail at display position number “C 4 ” while keeping the finger in contact with the touch panel  17 , as shown in  FIG. 10A , reference number “ 46 ” for the line in the thumbnail list having display position number “C 6 ” is stored in the temporary selection ending position memory area  13   e , and all reference numbers “ 2 - 46 ” ranging in succession from reference number “ 2 ” stored in the temporary selection starting position memory area  13   d  to reference number “ 46 ” stored in the temporary selection ending position memory area  13   e  are stored in the temporary selection list memory area  13   c . Consequently, thumbnails for image files corresponding to reference numbers “ 2 - 46 ” stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 10A . 
     If the user lifts the finger from the touch panel  17  at this time, the selection status flags for all reference numbers “ 2 - 46 ” stored in the temporary selection list memory area  13   c  are set to “selected” in the thumbnail list since the selection status flag for the image file corresponding to image number “ 2 ” stored in the temporary selection starting position memory area  13   d  is set to “unselected.” Consequently, thumbnails for image files having selection status flags set to “selected” are displayed on the LCD  16  in the selected state, as shown in  FIG. 10B . 
     However, if the user lifts the finger from the touch panel  17  in  FIG. 9D  while still contacting the scrolling arrow SA 2 , then selection status flags for all reference numbers “ 2 - 48 ” stored in the temporary selection list memory area  13   c  are set to “selected” in the thumbnail list since the selection status flag for the image file corresponding to the reference number “ 2 ” stored in the temporary selection starting position memory area  13   d  is set to “unselected.” Accordingly, thumbnails for image files having selection status flags set to “selected” are displayed on the LCD  16  in the selected state, as shown in  FIG. 10C . 
     Next, a method of selecting image files will be described with reference to  FIGS. 11A-12C . In this method, the user operates the scrolling arrow SA 1  to scroll thumbnails displayed on the LCD  16 . 
       FIGS. 11A-12C  are explanatory diagrams illustrating the method of selecting image files by operating the scrolling arrow SA 1  to scroll thumbnails displayed on the LCD  16 . 
     In the following example, it will be assumed that 48 image files are recorded in the thumbnail list stored in the thumbnail list memory area  13   b , each image file being assigned a unique reference number from “ 1 ” to “ 48 ” and the selection status flags for all image files being set to “unselected.” Accordingly, all thumbnails displayed on the LCD  16  are in an unselected state. 
     In the thumbnail list, the line having reference number “ 25 ” is the starting position for display position numbers and, hence, the display position number in this line is set to “A 1 ”, while the display position number in the next row having reference number “ 26 ” is set to “A 2 ”. In this way, the display position numbers are assigned sequentially to lines in the thumbnail list up to display position number “C 6 ” in increasing order of the reference numbers. 
     If the user touches the thumbnail at display position number “C 4 ” at this time, as shown in  FIG. 11A , reference number “ 40 ” in the line of the thumbnail list having display position number “C 4 ” is stored in both the temporary selection starting position memory area  13   d  and the temporary selection list memory area  13   c . Consequently, the thumbnail for the image file corresponding to reference number “ 40 ” stored in the temporary selection list memory area  13   c  is displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 11A . 
     In this example, the user next slides the user&#39;s finger to the thumbnail at display position number “A 6 ” while keeping the finger in contact with the touch panel  17 , as shown in  FIG. 11B . At this time, reference number “ 30 ” in the line of the thumbnail list having display position number “A 6 ” is stored in the temporary selection ending position memory area  13   e , and all reference numbers “ 30 - 40 ” ranging in succession from reference number “ 40 ” stored in the temporary selection starting position memory area  13   d  to reference number “ 30 ” stored in the temporary selection ending position memory area  13   e  are stored in the temporary selection list memory area  13   c . Consequently, thumbnails for image files corresponding to reference numbers “ 30 - 40 ” stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 11B . 
     Next, the user slides the finger to the scrolling arrow SA 1  at display position number “A 7 ” while the finger remains in contact with the touch panel  17 , as illustrated in  FIG. 11C . When the position of the user&#39;s finger reaches the scrolling arrow SA 1  at display position number “A 7 ”, the thumbnails are scrolled in the LCD  16 . Specifically, all thumbnails displayed in the first row of the LCD  16  are moved to the second row, all thumbnails in the second row are moved to the third row, and new thumbnails are displayed in the first row. 
     More specifically, when the user&#39;s finger touches the scrolling arrow SA 1  at display position number “A 7 ” on the LCD  16 , first display position numbers “A 1 -C 6 ” are modified in the thumbnail list. That is, display position number “A 1 ” is moved to the line of the thumbnail list with reference number “ 19 ”, display position number “A 2 ” is moved to the line with reference number “ 20 ”, and subsequent display position numbers are moved in the same way, with display position number “C 6 ” being moved to the line having reference number “ 36 ”. Hence, each display position number “A 1 -C 6 ” stored in the thumbnail list is moved up six lines in the list. 
     Next, thumbnails for image files corresponding to the modified display position numbers “A 1 -C 6 ” in the thumbnail list are displayed at display position numbers “A 1 -C 6 ” on the LCD  16 , and the reference number for the image file corresponding to the new thumbnail displayed at display position number “A 6 ” on the LCD  16  is stored in the temporary selection ending position memory area  13   e . Next, all reference numbers ranging in succession from the reference number stored in the temporary selection starting position memory area  13   d  to the reference number stored in the temporary selection ending position memory area  13   e  are stored in the temporary selection list memory area  13   c . Consequently, thumbnails for image files corresponding to the reference numbers stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in the temporarily selected state. The above process is repeated at prescribed intervals (every 2 seconds, for example) while the user&#39;s finger remains in contact with the scrolling arrow SA 1 , thereby continuing to scroll the thumbnails displayed on the LCD  16 . 
       FIG. 11D  shows the state of thumbnails displayed on the LCD  16  after the thumbnails were scrolled once from the state shown in  FIG. 11C . That is, display position number “A 1 ” has been moved to the line in the thumbnail list having reference number “ 19 ”, display position number “A 2 ” has been moved to the line having reference number “ 20 ”, and subsequent display position numbers have been moved in the same way, with display position number “C 6 ” being moved to the line with reference number “ 36 ”. 
     Therefore, reference number “ 24 ” is stored in the temporary selection ending position memory area  13   e , and all reference numbers “ 24 - 40 ” ranging in succession from reference number “ 40 ” stored in the temporary selection starting position memory area  13   d  to reference number “ 24 ” stored in the temporary selection ending position memory area  13   e  have been stored in the temporary selection list memory area  13   c . Consequently, thumbnails for image files corresponding to reference numbers “ 24 - 40 ” stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 11D . 
     If the user further slides the finger to the thumbnail at display position number “A 5 ” while keeping the finger in contact with the touch panel  17 , as shown in  FIG. 12A , reference number “ 23 ” for the line in the thumbnail list having display position number “A 5 ” is stored in the temporary selection ending position memory area  13   e , and all reference numbers “ 23 - 40 ” ranging in succession from reference number “ 40 ” stored in the temporary selection starting position memory area  13   d  to reference number “ 23 ” stored in the temporary selection ending position memory area  13   e  are stored in the temporary selection list memory area  13   c . Consequently, thumbnails for image files corresponding to reference numbers “ 23 - 40 ” stored in the temporary selection list memory area  13   c  are displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 12A . 
     If the user lifts the finger from the touch panel  17  at this time, the selection status flags for all reference numbers “ 23 - 40 ” stored in the temporary selection list memory area  13   c  are set to “selected” in the thumbnail list since the selection status flag for the image file corresponding to image number “ 40 ” stored in the temporary selection starting position memory area  13   d  is set to “unselected.” Consequently, thumbnails for image files having selection status flags set to “selected” are displayed on the LCD  16  in the selected state, as shown in  FIG. 12B . 
     However, if the user lifts the finger from the touch panel  17  while still contacting the scrolling arrow SA 1 , then selection status flags for all reference numbers “ 24 - 40 ” stored in the temporary selection list memory area  13   c  are set to “selected” in the thumbnail list since the selection status flag for the image file corresponding to the reference number “ 40 ” stored in the temporary selection starting position memory area  13   d  is set to “unselected.” Accordingly, thumbnails for image files having selection status flags set to “selected” are displayed on the LCD  16  in the selected state, as shown in  FIG. 12C . 
     In the first embodiment described above, when the user moves a finger over thumbnails to either the scrolling arrow SA 1  or SA 2  while keeping the finger in contact with the touch panel  17 , the MFP  1  scrolls the thumbnails displayed on the LCD  16  so that new thumbnails can be displayed. Without touching the newly displayed thumbnails, the newly displayed thumbnails will be set to the same selected state that would be set if the user touched the thumbnail displayed immediately to the left of the touched scrolling arrow SA 1  or SA 2 , making the operation simpler and more user-friendly. 
     Further, since the scrolling arrows SA 1  and SA 2  are displayed slightly above the bottom edge of the thumbnails displayed in the first row (uppermost row) on the LCD  16  or slightly lower than the upper edge of thumbnails in the third row (lowest row), the user is less likely to perform an unintentional scrolling operation by accidentally touching one of the scrolling arrows SA 1  and SA 2  when touching thumbnails in the second row (middle row). 
     Further, since the scrolling arrows SA 1  and SA 2  are displayed on the right side of the thumbnails in the sixth column (rightmost column) on the LCD  16 , the user is less likely to perform an unintentional scrolling operation by accidentally touching one of the scrolling arrows SA 1  and SA 2  when touching thumbnails in the first through fifth columns. Further, by displaying both of the scrolling arrows SA 1  and SA 2  on the same end of the LCD  16 , the user can scroll images intuitively. 
     While the scrolling arrows SA 1  and SA 2  are provided on the right side of the screen in this embodiment described above, the scrolling arrows SA 1  and SA 2  may be provided on the left side instead. In this case, the scrolling arrows SA 1  and SA 2  are preferably displayed to the left of thumbnails in the first column (leftmost column) displayed on the LCD  16 . When the user touches the scrolling arrow SA 1  in this case, the CPU  11  stores reference numbers for the line in the thumbnail list having display position number “A 1 ” in the temporary selection ending position memory area  13   e . When the user touches the scrolling arrow SA 2 , the CPU  11  stores the reference number in the line of the thumbnail list having display position number “C 1 ” in the temporary selection ending position memory area  13   e.    
     Further, while the thumbnails are scrolled upward or downward in this embodiment described above, the thumbnails may be scrolled leftward or rightward instead. In this case, the scrolling arrows SA 1  and SA 2  are displayed above thumbnails in the first row (uppermost row) or below thumbnails in the third row (lowermost row). By displaying both the scrolling arrows SA 1  and SA 2  on the same edge of the LCD  16 , the user can scroll thumbnails more intuitively. 
     Next, a method of operating the touch panel  17  when thumbnails are displayed in a single row on the LCD  16  will be described with reference to  FIGS. 13A-13H . 
       FIGS. 13A-13H  illustrate the method of operating the touch panel  17  for thumbnails displayed in one row on the LCD  16 . 
     In the following example, it will be assumed that ten image files are recorded in the thumbnail list stored in the thumbnail list memory area  13   b , with unique reference numbers “ 1 - 10 ” assigned to the image files and the selection status flags for all image files set to “unselected.” Hence, thumbnails displayed on the LCD  16  are in the unselected state. 
     As shown in  FIG. 13A , three thumbnails are displayed on the LCD  16 , with the corresponding reference number displayed in the lower right corner of each thumbnail. In this description, the thumbnail displayed in the left of the LCD  16  has display position number “A 1 ”, the thumbnail displayed in the center has display position number “A 2 ”, and the thumbnail displayed on the right has display position number “A 3 ”. Further, a scrolling arrow SA 3  displayed to the left of display position number “A 1 ” has display position number “A 0 ”, while a scrolling arrow SA 4  displayed to the right of display position number “A 3 ” has display position number “A 4 ”. 
     In  FIG. 13A , the thumbnail for the image file corresponding to reference number “ 3 ” in the thumbnail list is displayed at the display position on the LCD  16  having display position number “A 1 ”, the thumbnail for the image file corresponding to reference number “ 4 ” is displayed at the display position having display position number “A 2 ”, and the thumbnail for the image file corresponding to reference number “ 5 ” is displayed at the display position having display position number “A 3 ”. 
     If the user touches the thumbnail at display position number “A 2 ” at this time, as shown in  FIG. 13B , reference number “ 4 ” in the line having display position number “A 2 ” in the thumbnail list is stored in both the temporary selection starting position memory area  13   d  and the temporary selection list memory area  13   c . Consequently, the thumbnail for the image file corresponding to reference number “ 4 ” stored in the temporary selection list memory area  13   c  is displayed on the LCD  16  in a temporarily selected state, as shown in  FIG. 13B . 
     If the user subsequently slides the finger to the thumbnail at display position number “A 3 ” while keeping the finger in contact with the touch panel  17 , as shown in  FIG. 13C , reference number “ 5 ” having display position number “A 3 ” in the thumbnail list is stored in the temporary selection ending position memory area  13   e , and reference numbers “ 4 - 5 ” are stored in the temporary selection list memory area  13   c . Therefore, thumbnails for image files corresponding to reference numbers “ 4 - 5 ” are displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 13C . 
     If the user further slides the finger to the scrolling arrow SA 4  at display position number “A 4 ” while keeping the finger in contact with the touch panel  17 , as shown in  FIG. 13D , the thumbnails displayed on the LCD  16  are scrolled. Specifically, as shown in  FIG. 13E , the thumbnail corresponding to reference number “ 4 ” is displayed at the display position having display position number “A 1 ”, the thumbnail corresponding to reference number “ 5 ” is displayed at the display position having display position number “A 2 ”, and the thumbnail corresponding to reference number “ 6 ” is displayed at the display position having display position number “A 3 ”. Reference number “ 6 ” for the image file corresponding to the thumbnail displayed at display position number “A 3 ” is stored in the temporary selection ending position memory area  13   e  and reference numbers “ 4 - 6 ” are stored in the temporary selection list memory area  13   c . Accordingly, thumbnails for image files corresponding to reference numbers “ 4 - 6 ” are displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 13E . 
     The thumbnails displayed on the LCD  16  continue to scroll at prescribed intervals while the user continues touching the scrolling arrow SA 4  at display position number “A 4 ”. For example, after a prescribed time, the thumbnail corresponding to reference number “ 7 ” is displayed at the display position having display position number “A 1 ”, the thumbnail corresponding to reference number “ 8 ” is displayed at the display position having display position number “A 2 ”, and the thumbnail corresponding to reference number “ 9 ” is displayed at the display position having display position number “A 3 ”. At this time, reference number “ 9 ” for the image file corresponding to the thumbnail displayed at display position number “A 3 ” is stored in the temporary selection ending position memory area  13   e , and reference numbers “ 4 - 9 ” are stored in the temporary selection list memory area  13   c . Accordingly, thumbnails for image files corresponding to reference numbers “ 4 - 9 ” are displayed on the LCD  16  in the temporarily selected state. 
     At this time, if the user slides the finger leftward to the thumbnail at display position number “A 2 ” while continuing to touch the touch panel  17 , as shown in  FIG. 13F , reference number “ 8 ” for the image file corresponding to the thumbnail displayed at display position number “A 2 ” is stored in the temporary selection ending position memory area  13   e  and reference numbers “ 4 - 8 ” are stored in the temporary selection list memory area  13   c . Accordingly, thumbnails for image files corresponding to reference numbers “ 4 - 8 ” are displayed on the LCD  16  in the temporarily selected state. 
     If the user lifts the finger from the touch panel  17  at this time, selection status flags for all reference numbers “ 4 - 8 ” stored in the temporary selection list memory area  13   c  are set to “selected” in the thumbnail list since the selection status flag for the image file corresponding to reference number “ 4 ” stored in the temporary selection starting position memory area  13   d  is set to “unselected” in the thumbnail list. Consequently, thumbnails for image files having a selection status flag set to “selected” are displayed in the selected state on the LCD  16 , as shown in  FIG. 13G . 
     Since the scrolling arrow SA 3  is displayed leftward of the right edge of the thumbnail displayed in the leftmost display position and the scrolling arrow SA 4  is displayed rightward of the left edge of the thumbnail displayed in the rightmost display position when thumbnails are displayed in a single row on the LCD  16 , the user is less likely to perform an unintended scrolling operation by mistakenly touching the scrolling arrow SA 3  or SA 4  when touching one of the middle thumbnails (thumbnails other than those on the left and right ends of the row). Aligning the thumbnails and the scrolling arrows SA 3  and SA 4  laterally in the display in this embodiment described above reduces the required vertical dimension of the display region. The horizontal dimension of the display region can also be reduced by positioning the scrolling arrows SA 3  and SA 4  as shown in  FIG. 13H . 
     While the thumbnails are displayed in the direction of rows in this embodiment described above, the thumbnails may be displayed in the direction of columns instead. In this case, the scrolling arrows SA 3  and SA 4  are displayed in the top or bottom of the screen, and preferably above the lower edge of the thumbnail displayed in the topmost position of the LCD  16  or below the upper edge of the thumbnail displayed in the bottommost position. Naturally, the horizontal dimension of the display region can be conserved when aligning the thumbnails and the scrolling arrows SA 3  and SA 4  in the vertical direction of the screen, while the vertical dimension of the display region can also be reduced by employing the display format shown in  FIG. 13H , except arranged vertically instead of horizontally. 
     With the first embodiment described above, the user can perform a simple operation of sliding a finger over thumbnails displayed on the LCD  16  and subsequently lifting the finger to specify all image files for reference numbers ranging continuously from the reference number of the image file corresponding to the first touched thumbnail to the reference number of the image file corresponding to the last touched thumbnail, selecting or deselecting all image files within the specified range. 
     Specifically, selection status flags for all image files within the range specified by sliding a finger over the thumbnails are set to “selected” if the selection status flag for the image file corresponding to the first touched thumbnail was set to “unselected,” and to “unselected” if the selection status flag for the image file corresponding to the first touched thumbnail was “selected.” Therefore, this operation is simple and easy to understand for the user since selection status flags of all image files within the range specified by sliding the finger are set based on the selection status flag of the image file corresponding to the first touched thumbnail. 
     Next, a second embodiment of the present invention will be described. In the second embodiment, the user performs a simple operation to individually specify two thumbnails by touching two thumbnails displayed on the LCD  16 . Through this simple operation, the user can specify all image files having reference numbers ranging sequentially from the reference number for the image file corresponding to the first touched thumbnail to the reference number for the image files corresponding to the next touched thumbnail in order to select or deselect all image files within this range. 
     As a result, the selection status flags for all image files within the specified range are set to “selected” when the selection status flag for the image file corresponding to the first touched thumbnail is set to “unselected” and are set “unselected” when the selection status flag for the image files corresponding to the first touched thumbnail is set to “selected.” In other words, selection status flags for image files within the specified range are determined based on the setting of the selection status flag for the image file corresponding to the first touched thumbnail, thereby making the operation simple and user-friendly. 
     Next, the printing process executed by the CPU  11  of the MFP  1  according to the second embodiment will be described with reference to  FIG. 14 .  FIG. 14  is a flowchart illustrating steps in this printing process and is executed when the user presses the Print Image File button  15   a  while a memory card  22   a  is inserted into one of the memory card slots  22 . 
     In this printing process, the user can select desired image files from those stored in the memory card  22   a  through simple operations and can direct the printer  21  to print images on printing paper based on the selected image files. 
     In S 41  of the printing process, the CPU  11  initializes the thumbnail list memory area  13   b . In S 42  the CPU  11  searches the memory card  22   a  for all image files, creates a thumbnail list based on the image files found in this search, and stores the thumbnail list in the thumbnail list memory area  13   b . When the thumbnail list is created (i.e., when in its initial state), the selection status flags for all image files are set to “unselected.” Further, “A 1 ” is set as the display position number in the line having reference number “ 1 ” in the thumbnail list, “A 2 ” is set as the display position number in the line having reference number “ 2 ”, and subsequent display position numbers are set sequentially in increasing order of the reference numbers up to display position number “C 6 ”. 
     In S 43  the CPU  11  displays the message “Select an image (press and hold to enter the continuous selection mode)” in the bottom of the display on the LCD  16 , as shown in  FIG. 16A . In S 44  the CPU  11  displays thumbnails on the LCD  16  for image files corresponding to the display position numbers “A 1 -C 6 ” in the thumbnail list stored in the thumbnail list memory area  13   b  and sets each thumbnail to the selected state or the unselected state based on the selection status flag for the corresponding image file. 
     In S 45  the CPU  11  determines whether the position of the user&#39;s finger touching the touch panel  17  is a display position on the LCD  16  for displaying a thumbnail. If the position of the user&#39;s finger on the touch panel  17  is a display position for a thumbnail (S 45 : YES), in S 46  the CPU  11  identifies the display position number of the thumbnail displayed at the display position on the LCD  16  matching the position of the user&#39;s finger on the touch panel  17 . 
     However, if the position of the user&#39;s finger does not correspond to the display position for a thumbnail (S 45 : NO), the CPU  11  skips S 45 -S 51  and advances to S 52 . 
     In S 47  the CPU  11  determines whether the user&#39;s finger has touched the thumbnail at the display position number identified in S 46  for at least a prescribed interval (1 second, for example). If the user&#39;s finger has not continually touched this thumbnail for a period exceeding the prescribed interval (S 47 : NO), in S 48  the CPU  11  determines whether the selection status flag of the image file corresponding to the display position number identified in S 46  is “unselected.” 
     If the selection status flag for the image file corresponding to the identified display position number is “unselected” (S 48 : YES), in S 49  the CPU  11  changes the selection status flag for this image file to “selected.”However, if the selection status flag is not “unselected” (S 48 : NO), then in S 50  the CPU  11  changes the selection status flag for this image file to “unselected.” Subsequently, the CPU  11  returns to S 44  and repeats the process in S 44 -S 50  described above. 
     On the other hand, if the CPU  11  determines in S 47  that the user&#39;s finger has touched the thumbnail at the display position number identified in S 46  for a period exceeding the prescribed interval (S 47 : YES), then the CPU  11  executes a continuous selection process in S 51 . 
     Here, the continuous selection process of S 51  will be described with reference to  FIG. 15 .  FIG. 15  is a flowchart illustrating steps in the continuous selection process. This process serves to determine a sequential range of reference numbers from the reference number corresponding to the thumbnail touched by the user for the prescribed interval to the reference number corresponding to a thumbnail directly touched by the user after first removing the finger from the touch panel  17 , and to change the selection status flags for all image files corresponding to the reference numbers in the determined range to “selected” or “unselected.” 
     In S 61  at the beginning of the continuous selection process, the CPU  11  initializes the temporary selection list memory area  13   c . In S 62  the CPU  11  identifies the display position number of the thumbnail displayed at the display position on the LCD  16  identical to the position of the user&#39;s finger on the touch panel  17  and stores the reference number of the image file corresponding to the identified display position number in both the temporary selection starting position memory area  13   d  and the temporary selection list memory area  13   c . In S 63  the CPU  11  sets thumbnails of image files corresponding to the reference numbers stored in the temporary selection list memory area  13   c  to the temporarily selected state on the LCD  16 . 
     In S 64  the CPU  11  waits as long as the user&#39;s finger has not separated from the touch panel  17  (S 64 : NO). When the user&#39;s finger has separated from the touch panel  17  (S 64 : YES), in S 65  the CPU  11  determines whether the position of the user&#39;s finger on the touch panel  17  after the finger separated from the touch panel  17  and subsequently touched the touch panel  17  corresponds to a display position for one of the scrolling arrows SA 1  and SA 2 . If the position of the user&#39;s finger does not correspond to a display position for one of the scrolling arrows SA 1  and SA 2  (S 65 : NO), then the CPU  11  skips S 66 -S 67  and advances to S 68 . 
     However, if the position of the user&#39;s finger corresponds to a display position for one of the scrolling arrows SA 1  and SA 2  (S 65 : YES), in S 66  the CPU  11  updates the display position numbers in the thumbnail list based on the display position number for the scrolling arrow SA 1  or SA 2  displayed at a position on the LCD  16  corresponding to the finger touching the touch panel  17 . In S 67  the CPU  11  displays thumbnails of image files corresponding to the display position numbers in the thumbnail list on the LCD  16  and sets each thumbnail to a selected state or an unselected state based on the selection status flag of the corresponding image file. 
     In S 68  the CPU  11  determines whether the position of the user&#39;s finger on the touch panel  17  corresponds to a display position for a thumbnail. If the position of the user&#39;s finger does not correspond to a display position for a thumbnail (S 68 : NO), then the CPU  11  returns to S 65  and repeats the process in S 65 -S 68  described above. However, if the position of the user&#39;s finger on the touch panel  17  corresponds to a display position for a thumbnail (S 68 : YES), then in S 69  the CPU  11  identifies the display position number of the thumbnail displayed at a display position on the LCD  16  matching the position of the user&#39;s finger on the touch panel  17  and stores the reference number of the image file corresponding to the identified display position number in the temporary selection ending position memory area  13   e.    
     In S 70  the CPU  11  stores in the temporary selection list memory area  13   c  all reference numbers in a continuous range from the reference number stored in the temporary selection starting position memory area  13   d  to the reference number stored in the temporary selection ending position memory area  13   e . In S 71  the CPU  11  determines whether the selection status flag of the image file corresponding to the reference number stored in the temporary selection starting position memory area  13   d  is set to “unselected.” 
     If the selection status flag for this image file is “unselected” (S 71 : YES), then in S 72  the CPU  11  changes selection status flags for all image files corresponding to reference numbers stored in the temporary selection list memory area  13   c  to “selected” in the thumbnail list stored in the thumbnail list memory area  13   b . However, if the selection status flag for the image file corresponding to the reference number stored in the temporary selection starting position memory area  13   d  is set to “selected” (S 71 : NO), then in S 73  the CPU  11  changes the selection status flags for all image files corresponding to reference numbers stored in the temporary selection list memory area  13   c  to “unselected” in the thumbnail list stored in the thumbnail list memory area  13   b . Subsequently, the CPU  11  ends the continuous selection process of S 51 . 
     Through the continuous selection process of S 51  described with reference to  FIG. 15 , the MFP  1  can determine a sequential range of reference numbers from the reference number corresponding to the thumbnail touched by the user for the prescribed interval to the reference number corresponding to a thumbnail directly touched by the user after first removing the finger from the touch panel  17 , and can change the selection status flags for all image files corresponding to the reference numbers in the determined range to “selected” or “unselected.” After completing the continuous selection process of S 51 , the CPU  11  returns to S 44  in  FIG. 14  and repeats the process of S 44 -S 51  in  FIG. 14 . 
     In S 52  of  FIG. 14  the CPU  11  determines whether the position of the user&#39;s finger on the touch panel  17  corresponds to a display position for either the scrolling arrow SA 1  or SA 2  displayed on the LCD  16 . If the position of the user&#39;s finger does correspond to a display position for the scrolling arrow SA 1  or SA 2  (S 52 : YES), then in S 53  the CPU  11  updates the display position numbers in the thumbnail list based on the display position number of the scrolling arrow SA 1  or SA 2  displayed at the position of the user&#39;s finger. Subsequently, the CPU  11  returns to S 44  and repeats the process in S 44 -S 53  described above. 
     However, if the user&#39;s finger is not at a display position of the scrolling arrow SA 1  or SA 2  displayed on the LCD  16  (S 52 : NO), then the CPU  11  skips S 53  and advances to S 54 . 
     In S 54  the CPU  11  determines whether the Cancel button  15   b  has been pressed. If the Cancel button  15   b  has been pressed (S 54 : YES), the CPU  11  ends the printing process. However, if the Cancel button  15   b  has not been pressed (S 54 : NO), in S 55  the CPU  11  determines whether the Print button  15   c  has been pressed. 
     If the CPU  11  determines that the Print button  15   c  has been pressed (S 55 : YES), in S 56  the CPU  11  reads image files having a selection status flag set to “selected” in the thumbnail list stored in the thumbnail list memory area  13   b  from the memory card  22   a , stores these image files in the image memory area  13   a , controls the printer  21  to print an image of each file on printing paper, and subsequently ends the printing process. However, if the Print button  15   c  has not been pressed (S 55 : NO), the CPU  11  returns to S 44  and repeats the process in S 44 -S 55  described above. 
     Through the printing process of  FIG. 14  described above, the user can specify two thumbnails displayed on the LCD  16  through a simple operation of touching the two thumbnails individually. In this way, the user can specify all image files having reference numbers ranging sequentially from the reference number of the image file corresponding to the first touched thumbnail to the reference number of the image file corresponding to the next touched thumbnail and can select or deselect all image files in the specified range. 
     Further, since the continuous selection process begins when the user touches and holds one thumbnail for a prescribed interval, the user is less likely to perform this operation by accident or another operation that unintentionally executes the continuous selection process. 
     Specifically, selection status flags for all image files within the specified range are set to “selected” if the selection status flag for the image file corresponding to the first touched thumbnail was set to “unselected,” and to “unselected” if the selection status flag for the image file corresponding to the first touched thumbnail was “selected.” Therefore, this operation is simple and easy to understand for the user since selection status flags of all image files within the specified range are set based on the selection status flag of the image file corresponding to the first touched thumbnail. 
     Next, a method of operating the touch panel  17  according to the second embodiment will be described with reference to  FIGS. 16A-16E . 
       FIGS. 16A-16E  are explanatory diagrams illustrating a method in which the user selects image files by touching two individual thumbnails displayed on the LCD  16  with a finger. 
     The following description assumes that the line having reference number “ 1 ” in the thumbnail list is the starting position for display position numbers and, hence, the display position number in this line is set to “A 1 ”. The display position number in the next line having reference number “ 2 ” is set to “A 2 ”. In this way, the display position numbers are assigned sequentially to lines in the thumbnail list up to display position number “C 6 ” in increasing order of the reference numbers. Further, the following description assumes that all selection status flags in the thumbnail list have been set to “unselected.” Therefore, all thumbnails displayed on the LCD  16  are in the unselected state. 
     If the user touches the thumbnail at display position number “B 3 ” for at least a prescribed interval (1 second, for example), as shown in  FIG. 16A , the reference number “ 9 ” in the line of the thumbnail list having display position number “B 3 ” is stored in both the temporary selection starting position memory area  13   d  and the temporary selection list memory area  13   c . Hence, the thumbnail for the image file corresponding to reference number “ 9 ” stored in the temporary selection list memory area  13   c  is displayed on the LCD  16  in the temporarily selected state, as shown in  FIG. 16B . 
     If the user then lifts the finger from the touch panel  17  and subsequently touches the thumbnail at display position number “C 4 ”, as shown in  FIG. 16C , the reference number “ 16 ” in the line of the thumbnail list having display position number “C 4 ” is stored in the temporary selection ending position memory area  13   e . Accordingly, reference numbers “ 9 - 16 ” are stored in the temporary selection list memory area  13   c.    
     Hence, all selection status flags for reference numbers “ 9 - 16 ” stored in the temporary selection list memory area  13   c  are set to “selected” in the thumbnail list because the selection status flag for the image file corresponding to reference number “ 9 ” stored in the temporary selection starting position memory area  13   d  is set to “unselected” in the thumbnail list. Consequently, thumbnails for image files having a selection status flag set to “selected” are displayed on the LCD  16  in the selected state, as shown in  FIG. 16D . 
     In the second embodiment described above, the user can perform a simple operation to touch two thumbnails individually among the thumbnails displayed on the LCD  16  to specify image files for all reference numbers ranging sequentially from the reference number of the image file corresponding to the first touched thumbnail to the reference number of the image file corresponding to the next touched thumbnail in order to select or deselect all image files within the specified range. 
     Here, selection status flags for all image files within the specified range are set to “selected” when the selection status flag of the image file corresponding to the first touched thumbnail is “unselected” and set to “unselected” when the selection status flag of the image file corresponding to the first touched thumbnail is “selected.” In other words, the selection status flags of image files within the specified range are set based on the setting of the selection status flag associated with the image file corresponding to the first touched thumbnail, thereby making the operation simpler and more user-friendly. 
     While the invention has been described in detail with reference to specific embodiments thereof, it would be apparent to those skilled in the art that many modifications and variations may be made therein without departing from the spirit of the invention, the scope of which is defined by the attached claims. 
     For example, in the second embodiment described above, the continuous selection process of S 51  shown in  FIG. 15  is executed when the user presses and holds an initial thumbnail among thumbnails displayed on the LCD  16 . However, it is also possible to provide a Continuous Selection Mode button on the display and execute the continuous selection process of S 51  when the user touches this Continuous Selection Mode button. In the continuous selection process in this case, all image files having reference numbers ranging in succession from the reference number for the image file corresponding to the first touched thumbnail to the reference number for the image file corresponding to the next touched thumbnail are specified and all specified image files are selected or deselected. 
     Further, in the first embodiment described above, thumbnails for user-selected image files remain displayed on the LCD  16  in the temporarily selected state while the user&#39;s finger is in contact with the touch panel  17 . However, two types or patterns of temporarily selected states may be used so that the user can visually determine whether the image files are selected or unselected. In other words, the style of the temporarily selected state of thumbnails displayed on the touch panel  17  is switched based on the selection status flag setting for the image file corresponding to the first touched thumbnail. 
     In both the first and second embodiments described above, image data stored in the memory card  22   a  is used as the target of selection, but the user may also select image data generated by the scanner  20  or image data acquired from a PC, external hard drive, or the like. 
     Further, while the MFP  1  having an image-selecting device was described in the first and second embodiments, the image-selecting device of the present invention is not limited to that in a multifunction peripheral. The present invention may also be applied to an image-selecting device provided in a digital still camera or the like.
An image-selecting device includes a storing unit, a displaying unit, a detecting unit, a reading unit, an identification data storing unit, a display controlling unit, an image data identifying unit, and an image data selecting unit. The displaying unit displays a plurality of images based on a plurality of pieces of image data and has a plurality of display regions for the plurality of images. The detecting unit detects each of the plurality of display regions receiving direct input by an indicator. The reading unit reads the plurality of pieces of image data from the storing unit. The identification data storing unit stores identification data for identifying the plurality of pieces of image data read by the reading unit and assigns a prescribed order to the identification data for the plurality of pieces of image data. The display controlling unit controls the displaying unit to display the plurality of images according to the prescribed order. The image data identifying unit identifies each of the plurality of pieces of image data for the image displayed in the display region detected by the detecting unit. When the image data identifying unit identifies two pieces of image data among the plurality of pieces of image data, the image data selecting unit, selects or deselects image data from one image data of the two pieces of image data to the other image data of the two pieces of image data according to the prescribed order of the identification data.