The mapping of sensory surfaces onto cortical areas as well as maps in inter-areal projections are classified and discussed in terms of space-variant image processing. The neurobiological phenomena discussed in this context include retinotopic maps, columnar organization, interactions between a retinotopic map and a uniform operation in a cortical area, and patchy or segregated projections of two or more areas to a common target area. We present a mathematical framework for describing the interaction of neural mappings and local image processing operations which allows functional interpretations. In an example from visual navigation, we show that neural maps are powerful tools for the parallel processing of visual information. Since mappings of the various types result in a spatial encoding of arbitrary stimulus information, image processing operations can be applied to information from other modalities or for higher-level problems as well. For this aspect of neural mapping, we adopt the term parametric mapping.