An apparatus and method is provided that detects four sides of a subject image included in a captured image. It is determined, based on a width and a height of the captured image and the detected four sides of the subject image, whether imaging guides of vertical lines are to be displayed or imaging guides of horizontal lines are to be displayed. The vertical lines are displayed in a left end and a right end of a region in which the captured image is displayed when it is determined that the imaging guides of the vertical lines are to be displayed. The horizontal lines are displayed in an upper end and a lower end of the region in which the captured image is displayed when it is determined that the imaging guides of the horizontal lines are to be displayed.