1. An image-selecting device comprising: 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; a reading unit that reads the plurality of pieces of image data from the storing unit; an identification data storing unit that 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; a display controlling unit that controls the displaying unit to display the plurality of images according to the prescribed order; an image data identifying unit that identifies each of the plurality of pieces of image data for the image displayed in the display region detected by the detecting unit; and an image data selecting unit that, when the image data identifying unit identifies two pieces of image data among the plurality of pieces of image data, selects or deselects one image data of the two pieces of image data, the other image data of the two pieces of image data, and image data between the one image data and the other image data according to the prescribed order of the identification data; wherein the detecting unit detects a display region corresponding to a position of direct input from the indicator on the displaying unit when the position of direct input moves on the displaying unit; wherein the image data identifying unit comprises: a first image data identifying unit that identifies, as first image data, image data first identified among the plurality of pieces of image data while the indicator continually applies direct input to the displaying unit; and a second image data identifying unit that identifies, as second image data, image data last identified among the plurality of pieces of image data while the indicator continually applies direct input to the displaying unit; wherein the image data selecting unit sets the one image data to the first image data identified by the first image data identifying unit and the other image data to the second image data identified by the second image data identifying unit; wherein the image-selecting device further comprises: a change detecting unit that detects whether image data identified by the image data identifying unit has changed to different image data as the position of direct input moves while the indicator continually applies direct input to the displaying unit; and wherein the display controlling unit controls the displaying unit to display images corresponding to the first image data, image data most recently identified by the image data identifying unit, and image data between the first image data and the most recently identified image data in the prescribed order of identification data in a differing state based on the images corresponding to selected image data and unselected image data when the change detecting unit detects that the image data identified by the image data identifying unit has changed to the different image data.