Abstract: The invention concerns a method of detecting from a vehicle a bend in a road comprising a surface and road edges, comprising the following operations: taking an image of a road scene unfolding in front of the vehicle and at least partly illuminated by the vehicle, determining, for each pixel in the image a light decrease gradient, analysing these decrease gradients and determining an image of the road edges, mathematically discriminating the gradients from the image of the road edges, analyzing this discrimination and determining edges, and an angle of the bend. The invention also concerns a system for implementing the method of the invention comprising a camera mounted in the vehicle, an image processing unit and a neural network.

Abstract: An electronic security device has a light-receiving interface that receives a modulated light signal emitted by the screen of a computer making use of the data medium, an output interface adapted to emit output information as a function of the received input information, and an electronic central unit connected to the receive and emit interfaces and adapted to determine the output information as a function of the input information and to cause said output information to be emitted.

Abstract: The invention concerns a method of detecting from a vehicle a bend on a road comprising a surface (1) and road edges (2, 3), comprising the following operations:

Abstract: A secure, optically readable data medium comprises a data-carrying zone readable by a read light beam, and at least a portion that is photosensitive, being provided with a photosensitive material and exposed to the read light beam. The photosensitive material contains an active compound taken from the family of diarylethenes.

Abstract: The invention provides a method of providing copy protecting to data recorded on a data medium of the CD-ROM type that is readable by means of a laser beam. Applications thus lie in providing copy protection for digital optical disks (CD-ROM, DVD-ROM, etc.). The medium includes a sensitive zone over at least a portion of its surface, said zone possessing at least one optical property that is modified on being illuminated by the laser beam. The method implies that a computer program using the data reads from the sensitive zone on at least two separate occasions and compares the results of the reads in order to verify that the optical property of the sensitive zone has indeed been modified. The modification to the optical property is maintained for a predetermined duration of modification. The sensitive Zone may cover the entire medium. The optical property that is modified may be index of reflection or polarization.

Abstract: An electronic security device has a light-receiving interface (10) that receives a modulated light signal emitted by the screen of a computer making use of the data medium, an output interface (11) adapted to emit output information as a function of the received input information, and an electronic central unit (7) connected to the receive and emit interfaces and adapted to determine the output information as a function of the input information and to cause said output information to be emitted.