1. A method of detecting a supporting surface region in an image captured by a camera, said method comprising: detecting an object in the image; determining one or more regions of the image in which a lower part of the detected object exists; determining a degree of confidence for each of the regions, the degree of confidence indicating likelihood of a corresponding region being a supporting surface region; selecting one or more of the regions based on each corresponding degree of confidence; determining similarity of other regions in the image to at least one of the selected regions; and detecting the supporting surface region based on the determined similarity.