Linear motion estimation for image sequence based accurate 3-D measurements

We present a method for making accurate 3-D measurements from monocular image sequences. The process of determining camera motion is completely separated from 3-D structure estimation. The algorithm has two steps: elimination of rotations and estimation of the camera translation. Elimination of rotations is based on pre-calibration, and estimation of the camera translation is based on locating the focus of expansion from image disparities. The method proposed utilizes the total least squares estimation technique. By using the motion data, the 3-D coordinates of the measurement points can be solved linearly up to a scale factor. Due to the nonrecursive nature of the method, it provides a fast approach for processing long image sequences in an accurate manner.