Helmut Cantzler Intensity images are of limited use in terms of estimation of surfaces. Pixel values are related to surface geometry only indirectly. Range images encode the position of surface directly. Therefore, the shape can be computed reasonably easy.
Range images are a special class of digital images.
Each pixel of a range image expresses the distance between a known reference frame and a visible point in the scene. Therefore, a range image reproduces the 3D structure of a scene. Range images are also referred to as depth images, depth maps, xyz maps, surface profiles and 2.5D images. Range images can be represented in two basic forms. The other is a matrix of depth values of points along the directions of the x,y image axes, which makes spatial organisation explicit.