1. An image processing apparatus, comprising: a first imaging unit that images a first direction; a second imaging unit that images a second direction, the second direction being different from the first direction; an additional-information generating unit that generates additional information based on a first image, the first image being obtained in imaging by the first imaging unit; and an additional processing unit that adds the additional information to image data of a second image, the second image being obtained in imaging by the second imaging unit.