Results 241 to 250 of about 49,732,844 (278)

Interactive Shape from Shading

2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05), 2005
Shape from shading (SfS) has always been difficult for real applications due to its intrinsic ill-posedness. In this paper, we propose an interactive SfS method which efficiently uses human knowledge in order to resolve ambiguity. We propose a global solution of continuous surfaces with a few constraints of surface normals that are interactively ...
Gang Zeng, Yasuyuki Matsushita, Long Quan, Heung-Yeung Shum   +3 more
openaire   +1 more source

Vector transport for shape-from-shading

Pattern Recognition, 2003
In this paper we describe a new shape-from-shading method. We show how the parallel transport of surface normals can be used to impose curvature consistency and also to iteratively update surface normal directions so as to improve the brightness error.
Fabio Sartori, Edwin R. Hancock
openaire   +1 more source

KNOWLEDGE-BASED SHAPE-FROM-SHADING

International Journal of Pattern Recognition and Artificial Intelligence, 1999
In this paper, we study the problem of recovering approximate shape from the shading of a three-dimensional object in a single image when knowledge about the object is available. The application of knowledge-based methods to low-level image processing tasks will help overcome problems that arise from processing images using a pixel-based approach ...
Nick Barnes, Zhi-Qiang Liu
openaire   +1 more source

Linear shape from shading

International Journal of Computer Vision, 1990
In many situations the reflectance function of a surface is approximately linear, and there is an effielent closed-form solution to the shape-from-shading problem. When boundary conditions (e.g., edges, singular points) are not available, good estimates of shape may still be extracted by using the assumption of general viewing position.
openaire   +2 more sources

Wavelet-based shape from shading

Proceedings of 1st International Conference on Image Processing, 1995
Abstract This paper proposes a wavelet-based approach for solving the shape from shading (SFS) problem. The proposed method takes advantage of the nature of wavelet theory, which can be applied to efficiently and accurately represent "things," to develop a faster algorithm for reconstructing better surfaces.
Jun-Wei Hsieh, Hong-Yuan Mark Liao, Ming-Tat Ko, Kuo-Chin Fan   +3 more
openaire   +2 more sources

Uniqueness in shape from shading

International Journal of Computer Vision, 1991
For general images of smooth objects wholly contained in the field of view, and for illumination symmetric around the viewing direction, it is proven that shape is uniquely determined by shading. Thus, shape from shading is a well-posed problem under these illumination conditions; and regularization is unnecessary for surface reconstruction and should ...
openaire   +2 more sources

A global algorithm for shape from shading

1993 (4th) International Conference on Computer Vision, 2002
A global algorithm for reconstructing shape from shading is described. This algorithm incorporates an earlier local algorithm that has been shown to be capable of fast, robust surface reconstruction for general surfaces if a small amount of information on the surface is provided.
John Oliensis, Paul Dupuis
openaire   +2 more sources

Qualitative shape from active shading

Proceedings 1992 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 2003
It is shown how to actively compute qualitative shape properties of a surface directly from image intensities without first quantitatively reconstructing the surface. The approach diverges from classical active shape-from-shading in that two different types of lighting conditions (a diffuse source and a point source) are used, rather than two instances
Michael S. Langer, Steven W. Zucker
openaire   +1 more source

Integrating stereo and shape from shading

Proceedings 1999 International Conference on Image Processing (Cat. 99CH36348), 2003
This paper presents a new method for integrating different low level vision modules, stereo and shape from shading, in order to improve the 3D reconstruction of visible surfaces of objects from intensity images. The integration process is based on correcting the 3D visible surface obtained from shape from shading using the sparse depth measurements ...
Mostafa Gadal-Haqq M. Mostafa, Sameh M. Yamany, Aly A. Farag   +2 more
openaire   +1 more source

Shape from Shading

1996
Die Rekonstruktion nichtplanarer Oberflachen aus einem einzelnen Irradianzbild ist eine der klassischen Problemstellungen der Szenenanalyse. Die Zielstellung ist sowohl theoretisch als auch fur die Praxis auserst interessant: Wie kann zum Beispiel aus den Irradianzen eines einzelnen Fotos die Form eines darin abgebildeten Objektes unter Ausnutzung von ...
Reinhard Klette, Andreas Koschan, Karsten Schlüns   +2 more
openaire   +1 more source