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Vehicle-Infrastructure-Driver Interactions Research Unit. Fog detection through use of a CCD onboard camera. Nicolas HAUTIERE ITPE PhD Student. Didier AUBERT Researcher. V.I.S.I.O.N. 2004 Rouen 28 septembre 2004. Presentation Overview. Introduction. Fog, light and vision.
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Vehicle-Infrastructure-DriverInteractions Research Unit Fog detection through use of a CCD onboard camera Nicolas HAUTIEREITPE PhD Student Didier AUBERT Researcher V.I.S.I.O.N.2004Rouen 28 septembre 2004
Presentation Overview • Introduction • Fog, light and vision • Fog effects on road vision • Modeling visual effects • Algorithm overview • Results • Conclusion
Fog detection through use of a CCD onboard camera VISION 2004 – Rouen – 28 septembre 2004 Introduction Measuring the atmospheric visibility: • Estimates the operation range of onboard perception sensors. • Constitutes a driving assistance. This work is part of the french ARCOS project.
Fog detection through use of a CCD onboard camera VISION 2004 – Rouen – 28 septembre 2004 Fog, light and vision • Fog microstructure • Fog is a concentration of water droplets suspended in the air, bringing visibility below one kilometer. • Light scattering • The daylight is scattered by fog droplets in all directions. This effect is described by an extinction coefficient k. • Visibility impairment • The fog reduces distant contrasts. This effect is described by the meteorological visibility: the greatest distance at which a black object of suitable dimensions can be seen.
Attenuation effect • Halo effect e-kd2 • Veiling effect e-kd e-kd1 surface Fog effects on road vision dumont@lcpc.fr
Fog detection through use of a CCD onboard camera VISION 2004 – Rouen – 28 septembre 2004 Modeling fog visual effects Distance of the object to the camera • Koschmieder’s law (1924) Extinction coefficient of fog Apparent luminance of the object Fog luminance at the horizon Intrinsic luminance of the object • International Commission on Illumination (CIE)
Fog detection through use of a CCD onboard camera At the inflection point Koschmieder’s law Computation of a band of measure Derivation of the curve of luminance Extraction of an inflection point Computation of the visibility distance VISION 2004 – Rouen – 28 septembre 2004 Resolving the equation Measure of the median luminance Algorithm overview Computation of ROI
Fog detection through use of a CCD onboard camera VISION 2004 – Rouen – 28 septembre 2004 Results Low dense fog – Vehicle following
Fog detection through use of a CCD onboard camera VISION 2004 – Rouen – 28 septembre 2004 Results Dense fog – Vehicle crossing
Fog detection through use of a CCD onboard camera VISION 2004 – Rouen – 28 septembre 2004 Results Dense fog – Curve
Fog detection through use of a CCD onboard camera VISION 2004 – Rouen – 28 septembre 2004 Conclusion This original method has the following advantages: • detects the presence of fog and measures the meteorological distance of visibility, • is based on a physical model of fog, • indicates if it is temporary inoperative, • needs only the presence of the road and the sky in the image to work, • isreal time performed, • works with a single camera.
Fog detection through use of a CCD onboard camera VISION 2004 – Rouen – 28 septembre 2004 NEW Application Contrast restoration on the road surface known on the road known known known deduced
Fog detection through use of a CCD onboard camera VISION 2004 – Rouen – 28 septembre 2004 NEW Application Contrast restoration on the road surface
