1. A method of determining a property of an image captured by a camera, the method comprising: determining vanishing points in the image; associating each pixel of the image with one or more of the vanishing points based on an orientation of the image gradient at the pixel; partitioning the image into a set of regions associated with a pair of the determined vanishing points based on the vanishing point associations for pixels in the image, boundaries of the regions being aligned with the associated vanishing points; determining, for at least one of the plurality of regions, a confidence value for the property of the image based on pixels in the region; and determining the property of the image for one or more pixels within said image based on the confidence value.