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Matching of high-dimensional features using nearest neighbors search is an important part of image matching methods which are based on local invariant features. In this work we highlight effects pertinent to high-dimensional spaces that are significant for matching, yet have not been explicitly accounted for in previous work. In our approach, we require(More)
The appearance of a surface texture is highly dependent on illumination. This is why current surface texture classification methods require multiple training images captured under a variety of illumination conditions for each class. We show that a single training image per class can be sufficient if the surfaces are of uniform albedo and smooth and shallow(More)
Helmholtz stereopsis guarantees unbiasedness by BRDF of the search for inter-image correspondences. In a practical setup, calibrated pixel sensitivity and corrected light anisotropy are required for the method to work well. In this paper a simple method for joint light-camera radiomet-ric calibration is proposed. Such calibration is shown to be an ill-posed(More)
We report results from a new methodology for investigating the visually perceived properties of surface textures. Densely sampled two-dimensional 1/f(beta) noise processes are used to model natural looking surfaces, which are rendered using combined point-source and ambient lighting. Surfaces are shown in motion to provide rich cues to their relief. They(More)
Photometric stereo with uncalibrated lights determines surface orientations ambiguously up to any regular transformation. If the surface reflectance model is separable with respect to the illumination and viewing directions, its inherent symmetries enable to design two previously unrecognized constraints on normals that reduce this ambiguity. The two(More)
Helmholtz Stereopsis (HS) has recently been explored as a promising technique for capturing shape of objects with unknown reflectance. So far, it has been widely applied to objects of smooth geometry and piecewise uniform Bidi-rectional Reflectance Distribution Function (BRDF). Moreover , for non-convex surfaces the inter-reflection effects have been(More)