Determining Surface Orientation by Uni-directional Photometric Flow Fields
نویسندگان
چکیده
In the Shape from Shading methods, an extended approach named Uni-directional Photometric Flow Fields is proposed in this paper. The reflectance property of the surface material is the uniform perfect diffuser, and the light source produces a uniform parallel beam and the illuminating direction is varied slightly only in the azimuth direction. The local surfacc orientation can be determined from the image density and its directional derivatives. It is shown that the zenith angle of the illuminating direction is also determined analytically. The errors caused by calculating the directional derivatives using the numerical differences from three input image densities are evaluated, and the effectiveness of the shape reconstruction algorithm is demonstrated by computer simulations.
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