A drawing object image and an image processing program are provided in an HTTP server 12. The drawing object image is downloaded by accessing the HTTP server 12 from a terminal unit 10. When the operator initiates a drawing operation on a WEB browser screen of terminal unit 10, an XMLHTTP request with coordinate position information of the cursor and the drawing radius information are transmitted to the HTTP server 12 to execute an image manipulation process. The WEB browser virtually divides the drawing operation object image into cells, identifies the cells in which the image contents are modified in the image manipulation process, and issues HTTP requests for the cell images. The HTTP server 12 cuts out the manipulated image in the requested areas and transmits them to the WEB browser and arranges them.