A method for estimating the horizon in an image of a camera to provide camera auto-calibration in the pitch direction. The method includes taking an image of a scene and generating a texture map of the image using horizontal edge detection analysis to locate horizontal edges in the scene. The method also includes providing a motion map by providing image differencing between subsequent images to find areas in the scene with no motion while the vehicle is moving. The texture map and the motion map are combined to identify the areas in the image that do not move and contain horizontal edges. A horizontal projection is generated from the combined map by counting white dots in the map in the horizontal direction. The horizontal projection is smoothed to eliminate noise and the location of the horizon is estimated in the image by identifying the maximum peak in the horizontal projection.