Efficient vanishing point detection method in unstructured road environments based on dark channel prior

Vanishing point detection is a key technique in the fields such as road detection, camera calibration and visual navigation. This study presents a new vanishing point detection method, which delivers efficiency by using a dark channel prior‐based segmentation method and an adaptive straight lines search mechanism in the road region. First, the dark channel prior information is used to segment the image into a series of regions. Then the straight lines are extracted from the region contours, and the straight lines in the road region are estimated by a vertical envelope and a perspective quadrilateral constraint. The vertical envelope roughly divides the whole image into sky region, vertical region and road region. The perspective quadrilateral constraint, as the authors defined herein, eliminates the vertical lines interference inside the road region to extract the approximate straight lines in the road region. Finally, the vanishing point is estimated by the meanshift clustering method, which are computed based on the proposed grouping strategies and the intersection principles. Experiments have been conducted with a large number of road images under different environmental conditions, and the results demonstrate that the authors’ proposed algorithm can estimate vanishing point accurately and efficiently in unstructured road scenes

An Electronic Auction Scheme Based on Group Signatures and Partially Blind Signatures

AbstractA new electronic auction scheme is proposed based on group signatures and partially blind signatures. At the same security strengthen, an optimization was done on the processes of electronic auction scheme and the dependence on trusted third party was reduced, moreover, multiple goods is auctioned at the same time, therefore, this scheme suited to large-scale electronic auction. Furthermore, due to application of vickrey auctions, the principle of optimal allocation of goods is easily satisfied