An image processing system to be mounted to a vehicle includes a radar adapted to measure distance and direction to an object based on reflected electromagnetic waves which are outputted to scan the exterior of the vehicle, an image-taking device such as a camera for obtaining an image, and an image processor for carrying out image processing on a specified image processing area in an image obtained by the image-taking device. The image processor is adapted to determine a center position of the image processing area according to a measurement point of an object detected by the radar and the size of the image processing area according to a beam profile of electromagnetic waves outputted from the radar.