1. A method for visual odometry using rigid structures identified by an antipodal transform, the method comprising: receiving a sequence of images captured by a camera; identifying rigid structures in the images using an antipodal transform; identifying correspondence between rigid structures in different image frames; and estimating a path of motion of the camera based on motion of corresponding rigid structures among the different image frames; wherein identifying rigid structures using the antipodal transform includes: generating a binary occupancy matrix for pixels in an image frame, wherein each element in the occupancy matrix indicates whether the pixel includes point on a structure or not; linearizing the matrix; marking occupied elements in the matrix as having a score that is different from unoccupied elements; and for each unoccupied element in the matrix, determining a distance in each of a plurality of directions to the nearest occupied element, computing a score for each distance, and summing the scores for each distance, and identifying the rigid structures using the scores.