This paper proposes a technique for 3D object scanning via in-hand manipulation, in which an object reoriented in front of a video camera with multiple grasps and regrasps. In-hand object tracking is a significant challenge under fast movement, rapid appearance changes, and occlusions. This paper proposes a novel video-segmentation-based object tracking algorithm that tracks arbitrary in-hand objects more effectively than existing techniques. It also describes a novel RGB-D in-hand object manipulation dataset consisting of several common household objects. Experiments show that the new method achieves 6% increase in accuracy compared to top performing video tracking algorithms and results in noticeably higher quality reconstructed models. Moreover, testing with a novice user on a set of 200 objects demonstrates relatively rapid construction of complete 3D object models.