An onboard image generator is provided. The onboard image generator includes a first camera capturing an image in front of or behind a vehicle, and a second camera and a third camera capturing images on right and left sides of the vehicle, respectively. Based on the images captured by the second and third cameras, a first viewpoint converter generates a set of symmetrical viewpoint conversion images shaped viewed toward the front or rear of the vehicle from a pair of parallel virtual viewpoints. Based on the image captured by the first camera, a center image generator generates a center image. A combined image generator generates a combined image by arranging the center image in a center of and arranging the set of viewpoint conversion images besides the center image.