In a rendering device Urnd, a CPU generates a lower viewpoint image based on captured images captured by image capture devices both securely mounted to a vehicle. Here, the lower viewpoint image shows a region rear of the vehicle viewed from those image capture devices. Then, the CPU executes viewpoint conversion processing onto the captured images, and generates an upper viewpoint image. Here, the upper viewpoint image shows also the region rear of the vehicle but viewed from a camera virtually placed above the vehicle. The CPU then stitches the upper and lower viewpoint images together to generate a drive assistant image. In such manner, the drive assistant image generated by the rendering device Urnd becomes informative enough for a driver of the vehicle.