This invention provides a service which allows the user of the client apparatus that submits a print request to preview an image to be printed, and can reduce the information volume with the client apparatus to achieve quick response, and prints a high-quality image with the requested size. For this purpose, a center server (102) on the network stores and manages display image data, and transfers requested display image data upon receiving a request from a client computer. Upon receiving a request including a print size from the client computer, the center server sends the print size and information that specifies an image to an image server which saves high-resolution images. Upon receiving the information, the image server processes high-resolution image data to have the designated size, and sends back the processed image data to the center server. The center server sends the received image data to a print server to make it print the data.