1. A method of detecting a three-dimensional corner in a space, the method comprising: acquiring a visible light image and an infrared image of a three-dimensional spatial area of interest; and extracting, by way of a processor, corner information of the three-dimensional spatial area of interest by detecting an edge having a first orientation from the acquired visible light image and by detecting an edge having a second orientation from the acquired infrared image, wherein the second orientation is orthogonal to the first orientation.