1. An image processing apparatus comprising: a warping unit configured to warp, between an image of a first viewpoint and an image of a second viewpoint different from the first viewpoint, a picture of the image of the first viewpoint to generate a picture of an warped image obtained by converting the picture of the image of the first viewpoint into an image obtainable in the second viewpoint; and a reference picture selection unit configured to acquire a reference index indicating a reference picture to be referred to generate a predicted image of an object block to be decoded of a picture of the image of the second viewpoint, and to select the reference picture from reference picture candidates including at least the picture of the warped image based on the reference index.