Received electronic mail includes a text code and a pictographic character code, for example. A non-stereoscopic process is performed on an image of characters by the text code, and a stereoscopic process is performed on an image of a pictographic character by the pictographic character code. The stereoscopic process allows a viewer to observe a pictographic character representing a car LP shifted to left (shown with a dotted line) through the parallax barrier only with the right eye R, and to observe the pictographic character representing a car RP shifted to right (shown with a dotted line) through the parallax barrier only with the left eye L. Accordingly, the viewer perceives (stereoscopically views) the pictographic character representing a car at a position as if to be protruding from a display surface. Therefore, all the characters in a text are not simply stereoscopically displayed but the pictographic character, and the like, is stereoscopically viewed overlapped on characters to be non-stereoscopically viewed.