1. A method comprising: capturing by an image capturing unit of a mobile device images of a scene including a target object; tracking a position of a stationary reference object appearing in the images captured by the image capturing unit; determining a motion of the mobile device based on the tracked position of the stationary reference object in the captured images; and detecting from the captured images variations in one or more varying features comprising small motion variations occurring on a surface of the target object based, at least in part, on the motion of the mobile device determined based on the tracked position of the stationary reference object in the captured images, the variations in the one or more varying features comprising the small motion variations occurring on the surface of the target object being independent of a target object position of the target object in the scene.