A digital image processing apparatus may display an image that can be converted into other images by using a rapid sliding method. The digital image processing apparatus may include a storage medium in which a first image file and a second image file are stored and a buffer in which information about a first synthesized image, including a first image corresponding to the first image file and a second image corresponding to the second image file disposed adjacent to each other, is stored. The digital image processing apparatus may further include a display unit that displays at least one of the first image, a first partial synthesized image, and the second image by using a piece of the information about the first synthesized image. The first partial synthesized image may include a portion of the first image and a portion of the second image disposed adjacent to each other.