A native client transmits, in accordance with a request from an image processing plugin application executed in a Java execution environment, a processing request for requesting execution of image processing using a native module executed in a C/C++ execution environment. A native server receives the processing request transmitted from the native client and executes the image processing by executing the native module in accordance with the received processing request. The native server is operated on a native control process that uses a memory space independent of a memory space used in the Java execution environment.