1. An image processing apparatus, comprising: a first imaging unit that is configured to image a first direction to obtain a first image; a second imaging unit that is configured to image a second direction to obtain a second image, the second direction being different from the first direction; an additional-information generating unit that is configured to generate additional information based on the first image to obtain a third image; a combining unit that is configured to combine the third image with the second image to obtain a fourth image, the fourth image having an aspect ratio that is the same as an aspect ratio of the second image; and a viewing-angle converting unit that is configured to perform viewing-angle conversion processing on the second image, wherein, to generate the additional information based on the first image, the additional-information generating unit is further configured to crop the first image by cutting out an area including a main subject on the first image, and wherein the combining unit is configured to combine the third image with the second image on which the viewing-angle conversion processing is performed.