Illumination control as a means of enhancing image features in active vision systems

In this paper, illumination control has been studied as a means of enhancing image features. Such features are points, edges, and shading patterns, which provide important cues for the interpretation of an image of a scene and the recognition of objects present in it. Based on approximate expressions for the reflectance map of Lambertian and general surfaces, a rigorous discussion on how intensity gradients are dependent on the direction of the light is presented. Subsequently, three criteria for the illumination of convex-shaped cylindrical surfaces are given. Two of these, the contrast equalization criterion and the max-min equalization criterion, are developed for optimal illumination of convex polyhedrons. The third, denoted shading enhancement, is applicable for the illumination of convex curved objects. Examples illustrate the merit of the criteria presented.

[1]  James F. Blinn,et al.  Texture and reflection in computer generated images , 1976, CACM.

[2]  David R. Warn,et al.  Lighting controls for synthetic images , 1983, SIGGRAPH.

[3]  K. Torrance,et al.  Biangular reflectance of an electric nonconductor as a function of wavelength and surface roughness , 1965 .

[4]  K. Torrance,et al.  Theory for off-specular reflection from roughened surfaces , 1967 .

[5]  Bui Tuong Phong.  Illumination for computer generated pictures , 1975, Commun. ACM.

[6]  Michael Potmesil,et al.  A lens and aperture camera model for synthetic image generation , 1981, SIGGRAPH '81.

[7]  Mark S. Rea,et al.  Toward a Model of Visual Performance: Foundations and Data , 1986 .

[8]  Alex Pentland,et al.  Local Shading Analysis , 1984, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[9]  James F. Blinn,et al.  Models of light reflection for computer synthesized pictures , 1977, SIGGRAPH.

[10]  B K Horn,et al.  Calculating the reflectance map. , 1979, Applied optics.

[11]  Donald P. Greenberg,et al.  Polygon shadow generation , 1978, SIGGRAPH.

[12]  Turner Whitted,et al.  An improved illumination model for shaded display , 1979, CACM.

[13]  Nasser Kehtarnavaz,et al.  A 3-D Contour Segmentation Scheme Based on Curvature and Torsion , 1988, IEEE Trans. Pattern Anal. Mach. Intell..

[14]  Rui J. P. de Figueiredo,et al.  Simultaneous estimation of shape and reflectance map from photometric stereo , 1992, CVGIP Image Underst..

[15]  James F. Blinn,et al.  The progression of realism in computer generated images , 1977, ACM '77.