In an initial stage where an image obtained by image sensing is displayed,
image data in a resolution depending on an image display area of display
unit is displayed, thereby a high response can be maintained with respect
to a request to display a next image or the like. Further, if a request
with an enlargement ratio higher than that in the initial stage has been
made, a display image is generated based on image data in a high
resolution, thereby a user's request for enlarged display or the like can
be fulfilled. When an image (JPEG file) stored in a recording medium is
to be displayed, low resolution image data in 640.times.480 pixel size
equivalent to the resolution of the display unit and high resolution
image data in an original high resolution indicated with the image file
are generated. In the initial stage, the low resolution image data is
displayed. If an enlargement request has been made, partial image data
cut out from the high resolution image data is resized and is displayed.