Compatibility with an operating system is maintained, and a high-quality
print image is efficiently previewed with a simple arrangement and small
memory area. A printer driver program executed by a host computer (15)
which controls the operation of a printer (7) adopts a processing
arrangement in which a print processor (5) is interposed between a
preview request from a previewer (8) and generation of image data by a
printer graphic driver (6). This processing arrangement causes the
printer graphic driver (6) to create image data for a preview display.
The created image data is transferred to the previewer (8) in accordance
with an instruction from the print processor (5).