Abstract: To authenticate images taken by image capturing elements (3) of offending vehicles, for example, when exceeding the authorized speed, provided elements are provided for allowing informative data on the offence to be supplied, such as the speed of the vehicle, the date, the time and the place of the offence and various processing methods are provided which enable, during exploitation of the images, detection of whether or not manipulations have been carried out on the images.

Abstract: To authenticate images taken by image capturing elements (3) of offending vehicles, for example, when exceeding the authorized speed, provided elements are provided for allowing informative data on the offence to be supplied, such as the speed of the vehicle, the date, the time and the place of the offence and various processing methods are provided which enable, during exploitation of the images, detection of whether or not manipulations have been carried out on the images.

Abstract: The invention concerns a method for transmitting in an area (100) information items in the form of sound waves representing a signal X(t), through a loudspeaker enclosure (2), said method comprising a step of setting up a public address system which consists in applying to the input of the loudspeaker enclosure (2) an electric signal P(t)=W(t) ?X(t) wherein is the convolution product and W(t)=S(?t)? I(t), wherein S(?t) is the temporal return of the pulse response S(t) between the enclosure and the target zone (101) belonging to the area to be fitted with a P.A. system (100) t representing time, and I(t) is the temporal response of the product e?2inft0.Sc (f), wherein f represents the frequency, t0 is a constant Sc(f)=1/(S1(f))?, ? being a non-null positive number and S1(f) being a real function obtained by peak clipping of the modulo I S(f) I of the frequency response S(f) of S(t).