Abstract: A method of detecting the presence of an element (fog, rain, etc. . . . ) disturbing the visibility of a scene illuminated by a headlight (105, 107) at night. The method comprises: a) acquiring an image of the scene with the help of a camera (120); b1) detecting the light sources in the image; b2) detecting the presence of the disturbing element as a function of the halo (H) appearing in the image in the vicinity of the light sources; c) detecting the presence of the disturbing element in the image as a function of the backscattering of the light emitted by the light sources; and d) weighting the results of the detections performed in steps b2) and c) in such a manner as to output an indication concerning the presence of the element disturbing the visibility of the scene. The method provides satisfactory results in an environment with or without lighting. The invention also provides a computer program and a device for implementing the method.

Abstract: Devices and methods for detecting of drops on a transparent wall through which digital image is acquired by means of an image acquisition system. The method includes establishing a gradient image from the digital image by assigning to each pixel the value of the gradient for the pixel; filtering the gradient image by assigning to each pixel a value obtained by rank filtering; and establishing a mask representing the position of the detected drops in the digital image by activating the pixels for which the difference between the value of the pixel in the filtered image and the value of the pixel in the gradient image exceeds a predetermined value.

Abstract: A method of detecting the presence of an element (fog, rain, etc. . . . ) disturbing the visibility of a scene illuminated by a headlight (105, 107) at night. The method comprises: a) acquiring an image of the scene with the help of a camera (120); b1) detecting the light sources in the image; b2) detecting the presence of the disturbing element as a function of the halo (H) appearing in the image in the vicinity of the light sources; c) detecting the presence of the disturbing element in the image as a function of the backscattering of the light emitted by the light sources; and d) weighting the results of the detections performed in steps b2) and c) in such a manner as to output an indication concerning the presence of the element disturbing the visibility of the scene. The method provides satisfactory results in an environment with or without lighting. The invention also provides a computer program and a device for implementing the method.

Abstract: A method for detection of drops on a transparent wall through which digital images (I11-I15,I111-I115,I211-I215,I311-I315) are acquired by means of an image acquisition system, comprising the following steps: b) a gradient image is established from the digital image (I16) by assigning to each pixel the value of the gradient for the pixel; c) the gradient image is filtered by assigning to each pixel a value obtained by rank filtering; d) a mask representing the position of the detected drops in the digital image is established by activating the pixels for which the difference between the value of the pixel in the filtered image and the value of the pixel in the gradient image exceeds a predetermined value. This method enables robust detection of drops in the image or the sequence of images. Program and device for detection of drops for executing this method.

Abstract: The invention relates to a device for determining visibility distance in a landscape. The device comprises a camera for taking an image of said landscape; means for storing said image; means for associating each pixel of the image with information representative of the distance between the camera and the point in the landscape corresponding to said pixel, thereby obtaining a map of distances; means for processing the image to detect whether a pixel of the image presents contrast greater than a predetermined value relative to at least some adjacent pixels; means for applying said processing for detecting contrast successively to the pixels of the image beginning from the pixel corresponding to the greatest distance and continuing to the first pixel found to satisfy the contrast condition; and means for associating said pixel with distance information from said map of distances.

Abstract: The invention relates to a device for determining visibility distance in a landscape. The device comprises a camera for taking an image of said landscape; means for storing said image; means for associating each pixel of the image with information representative of the distance between the camera and the point in the landscape corresponding to said pixel, thereby obtaining a map of distances; means for processing the image to detect whether a pixel of the image presents contrast greater than a predetermined value relative to at least some adjacent pixels; means for applying said processing for detecting contrast successively to the pixels of the image beginning from the pixel corresponding to the greatest distance and continuing to the first pixel found to satisfy the contrast condition; and means for associating said pixel with distance information from said map of distances.