Numerical Shape from Shading and Occluding Contours in a Single View
نویسنده
چکیده
An iterative method of using occluding boundary information is proposed to compute surface slope from shading. We use a stereographic space rather than the more commonly used gradient space in order to express occluding boundary information. Further, we use "average" smoothness constraints rather than the more obvious "closed loop" smoothness constraints. We develop alternate constraints from the definition of surface smoothness. since the closed loop constraints do not work in the stereographic space. We solve the image irradiance equation iteratively using a Gauss-Seidel method applied to the the constraints and boundary information. Numerical experiments show that the method is effective. Finally, we analyze SEM (Scanning Electron Microscope) pictures using this method. Other applications are also proposed.
منابع مشابه
Comment on "Numerical Shape from Shading and Occluding Boundaries"
The paper ‘Numerical shape from shading and occluding boundaries” [ I O ] proposed a method to determine the 3D shape of an object from a single brightness image using the smoothness constraint on surface orientations, and the orientations of the surface given along an occluding boundary. This paper contributed both a specific algorithm for solving a specific problem, and a general approach tha...
متن کاملAutomatic Estimation of the Projected Light Source Direction
We present a fully automatic algorithm for estimating the projected light source direction from a single image. The requirement is that there exists a segment of an occluding contour of an object with locally Lambertian surface reflectance in the image. The algorithm consists of three stages. First a heuristic algorithm picks out potential occluding contours using color and edge information. Se...
متن کاملThree-dimensional object shape from shading and contour disparities.
Both non-Lambertian shading, specularities in particular, and occluding contours have ill-matched binocular disparities. For example, the disparities of specularities depend not only on a surface's position but also on its curvature. Shading and contour disparities do in general not specify a point on the surface. I investigated how shading and contours contribute to perceived shape in stereosc...
متن کاملNumerical Shape from Shading and Occluding Boundaries
An iterative method for computing shape from shading using occluding boundary information is proposed. Some applications of this method are shown. We employ the stereographic plane to express the orientations of surface patches, rather than the more commonly .used gradient space. Use of the stereographic plane makes it possible to incorporate occluding boundary information, but forces us to emp...
متن کاملQualitative shape from shading, highlights, and mirror reflections.
The human visual system has a remarkable ability to perceive three-dimensional (3-D) surface shape from shading and specular reflections. This paper presents two experiments that examined the perception of local qualitative shape under various conditions. Surfaces were rendered using standard computer graphics models of matte, glossy, and mirror reflectance and were viewed from a small oblique ...
متن کامل