1. A three-dimensional image display apparatus comprising: a display module including a display surface having a vertical direction and a horizontal direction, in which pixels each having a predetermined width are arranged in rows and columns; a parallax barrier installed in front of the display module and having optical apertures each extending substantially linearly and arranged at a horizontal pitch equal to a integral multiple of the predetermined width of the pixel, the optical apertures so controlling light rays from the pixels as to define, on the display surface, elemental images each of which has a width determined depending on an observation standard viewing distance; a first processing unit configured to divide a parallax component image into pieces corresponding to the respective columns in a normal display mode, the parallax component image being obtained by subjecting the subject to perspective projection substantially determined by the viewing distance in the vertical direction and to orthographic projection in the horizontal direction, each predetermined range of the elemental images being allotted to one column and displayed on the display module to generate a three-dimensional image with a continuous viewpoint; and a second processing unit configured to divide a parallax component image into pieces corresponding to the respective columns in a compressed and emphasized display mode, the parallax component image being obtained by subjecting the subject to perspective projection substantially determined by the viewing distance in both vertical and horizontal directions, each predetermined range of the elemental images being allotted to one column and displayed on the display module to generate a three-dimensional image with a continuous viewpoint in which a subject image is compressed in a depth direction and emphasized in the vertical and horizontal directions.