This paper addresses the problem of calibrating camera lens distortion, which can be significant in medium to wide angle lenses. Our approach is based on the analysis of distorted images of straight lines. We derive new distortion measures that can be optimized using nonlinear search techniques to find the best distortion parameters that straighten these lines. Unlike the other existing approaches, we also provide fast, closed-form solutions to the distortion coefficients. We prove that including both the distortion center and the decentering coefficients in the nonlinear optimization step may lead to instability of the estimation algorithm. Our approach provides a way to get around this, and, at the same time, it reduces the search space of the calibration problem without sacrificing the accuracy and produces more stable and noise-robust results. In addition, while almost all existing nonmetric distortion calibration methods needs user involvement in one form or another, we present a robust approach to distortion calibration based on the least-median-of-squares estimator. Our approach is, thus, able to proceed in a fully automatic manner while being less sensitive to erroneous input data such as image curves that are mistakenly considered projections of three-dimensional linear segments. Experiments to evaluate the performance of this approach on synthetic and real data are reported.

The objectives of this effort are: (1) to provide a faster (parallel) implementation to a previously implemented ATM network design simulator, and (2) to compare two different parallel and distributed computing (PDC) architectures in order to select one to be the architecture for this new parallel version. To improve the performance of the previously implemented GA, two parallel versions are developed using two different approaches. The first uses message passing interface (MPI) function calls embedded in C++ programs on a network of workstations. The second version is developed for a multiprocessor system using a C/C++ parallel compiler. This paper describes the approaches used to develop the parallel versions, the design of parallel applications and the results of all the experiments that were done to study the effect of all the design parameters on system performance.