Illumination: a directional filter of texture?
Mike J. Chantler, George T. Russell, L.M. Linnett · 1994
This paper uses theory, simulation, and laboratory experiment, to show that directional illumination, used during the image acquisition process, acts as a directional filter of three dimensional texture. It is shown that the directional characteristics of image texture are not intrinsic to the physical texture being imaged, as they are affected by the direction of the illumination. This result has important implications for texture classification schemes: as many use directional characteristics for discrimination purposes. Variation of illuminant direction is shown to significantly affect a common texture measure: the Laws ' L5E5 operator [1]. 1.