When estimating distance to an object in an image using a single camera, data acquired by an onboard accelerometer is analyzed to determine camera speed as the user takes a video of the object of interest. The compression that results during video processing is used to derive motion vectors for the object of interest in the scene. The motion vectors have an opposite direction to the camera motion and a magnitude that is a function of the unknown object distance and a known magnification level. The object distance is calculated from the estimated velocity and motion vector magnitude.