1. A method comprising: accessing, from a video frame stored in a memory, a two-dimensional image indicative of a three-dimensional object; detecting homography between said two-dimensional image indicative of said three-dimensional object and a reference object image; determining whether said homography indicates pose suitable for image augmentation based, at least in part, on a ratio of a first span to a second span of an elliptically-shaped area that encompasses at least some of a plurality of inliers distributed in said two-dimensional image; and responsive to determining that said homography indicates pose suitable for image augmentation: tracking said two-dimensional image, from said video frame, in one or more successive video frames; and inserting said reference object image into at least one of said one or more successive video frames.