1. A method for image-based weather condition detection, using image processing methods in moving vehicles comprising a driving assistant system, the method comprising: detecting road weather conditions by: identifying a group of bright pixels in video images produced by an image-based road characterization, and determining whether said bright pixels are caused by reflections due to one selected from a group consisting of rainfall, snowfall, a wet surface, or a snowy surface, wherein the driving assistant system comprises a lane-keeping system.