Results 151 to 160 of about 562,132 (184)

Observability of shape from focus

Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171), 2002
We consider a closed-loop system consisting of a commercial video camera with auto-focus. We view the position of the lens as the controlled input, the brightness array on the CCD sensor as the measured output, and the auto-focus' task to maintain a region of the image "in focus".
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Microscopic shape from focus with optimal illumination

CVPR 2011 WORKSHOPS, 2011
We present a novel method for compensating illumination artifacts in shape from focus reconstruction that does not require additional measurement time. Frequently applied in optical microscopy, shape from focus requires rich surface texture over the whole scene. This prerequisite is violated in saturated image regions.
Martin Lenz, Matthias Ruther, Horst Bischof   +2 more
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Improving Shape from Focus Using Defocus Information

18th International Conference on Pattern Recognition (ICPR'06), 2006
Shape from focus (SFF) method determines the degree of focus in a sequence of observations to estimate the shape of a 3-D object. Existing SFF algorithms use an ad hoc interpolation strategy to account for the error due to the finite step-size by which the translational table is moved while capturing the images.
K.S. Pradeep, A.N. Rajagopalan
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An unorthodox approach towards shape from focus

2011 18th IEEE International Conference on Image Processing, 2011
Although numerous methods have been recently proposed in recovering shape from image focus, all follow similar precedent of focus measure application after image acquisition and depth is recovered by maximizing the focus curves obtained via this application. This is followed by utilizing approximation techniques to refine the initial depth map. In this
Mannan Saeed Muhammad, Tae-Sun Choi
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Microscopic shape from focus using active illumination

Proceedings of 12th International Conference on Pattern Recognition, 2002
Shape from focus relies on surface texture for the computation of depth. In many real-world applications, surfaces can be smoothly shaded and lacking in detectable texture. In such cases, shape from focus generates inaccurate and sparse depth maps. This paper presents a novel extension to the original shape from focus method. A strong texture is forced
M. Noguchi, S.K. Nayar
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Shape from Focus.

1989
Abstract: "Rough surfaces pose a challenging shape extraction problem. Images of rough surfaces are often characterized by high frequency intensity variations, and it is difficult to perceive the shapes of these surfaces from their images. The shape-from-focus method described in this paper uses different focus levels to obtain a sequence of object ...
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Shape From Focus by Total Variation

IVMSP 2013, 2013
Usually, in Shape From Focus (SFF) methods, a single focus measure is applied on an image sequence to obtain an initial depth map and then an approximation technique is used to recover three-dimensional (3D) shape of an object. However, different focus measures perform differently in diverse conditions and it is hard to get accurate 3D shape based on a
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Microscopic Shape from Focus using White Light Interferometric Fringes

Imaging and Applied Optics 2018 (3D, AO, AIO, COSI, DH, IS, LACSEA, LS&C, MATH, pcAOP), 2018
In this work we study the use of a focus measure to improve the 3D reconstruction of low reflectivity microscopic samples using white light interference microscopy. Simulation and experimental results show the improved reconstruction.
Marrugo Hernández, Andrés Guillermo, Altamar Mercado, Hernando Rafael, Patiño Vanegas, Alberto   +2 more
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Shape from Focus through Laplacian Using 3D Window

2008 Second International Conference on Future Generation Communication and Networking, 2008
One of the fundamental objectives of computer vision is to reconstruct a three-dimensional (3D) structure of objects from two-dimensional (2D) images. The basic idea of image focus is that objects at different distances from a lens are focused at different distances.
Youngeun An, Gwangwon Kang, Il-Jung Kim, Hyun-Sook Chung, Jongan Park   +4 more
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High Resolution Image Reconstruction in Shape from Focus

2007 IEEE International Conference on Image Processing, 2007
In the Shape from Focus (SFF) method, a sequence of images of a 3D object is captured for computing its depth profile. However, it is useful in several applications to also derive a high resolution focused image of the 3D object. Given the space-variantly blurred frames and the depth map, we propose a method to optimally estimate a high resolution ...
R. R. Sahay, A. N. Rajagopalan
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