1. A computer-implemented process for calibrating a set of cameras comprising the process actions of: capturing an image with each camera of a set of cameras simultaneously wherein one camera is a master camera and the other cameras are slave cameras; extracting feature points in each image from each of the set of cameras; using the extracted feature points, estimating a set of inter-image homographies, wherein each of the inter-image homographies are defined by a master camera and a second slave camera each having different positions looking at a common plane linked by a 3Ã—3 homography H defined by H â‰… A 2 ( R + t â¢ â¢ n T d ) â¢ A 1 - 1 where A 1 , and A 2 , are the intrinsic matrices of the master and slave cameras, respectively; the symbol â‰… denotes equal up to a nonzero scale: R and t are the rotation and translation extrinsic parameters of the slave camera in the reference coordinate frame of the master, and, n is the unit normal vector of the ground plane; determining a linear solution of extrinsic camera parameters for each camera using said estimated set of estimated inter-image homographies.