Results 1 - 10 of 185

Robust radiometric calibration and vignetting correction

by Seon Joo Kim, Student Member, Marc Pollefeys - IEEE Transactions on Pattern Analysis and Machine Intelligence , 2008
"... In many computer vision systems, it is assumed that the image brightness of a point directly reflects the scene radiance of the point. However, the assumption does not hold in most cases due to nonlinear camera response function, exposure changes, and vignetting. The effects of these factors are mos ..."
Abstract - Cited by 46 (7 self) - Add to MetaCart
are most visible in image mosaics and textures of 3D models where colors look inconsistent and notable boundaries exist. In this paper, we propose a full radiometric calibration algorithm that includes robust estimation of the radiometric response function, exposures, and vignetting. By decoupling

Robust Shadow and Illumination Estimation Using a Mixture Model

by Alexandros Panagopoulos, Dimitris Samaras, Nikos Paragios , 2009
"... Illuminant estimation from shadows typically relies on accurate segmentation of the shadows and knowledge of exact 3D geometry, while shadow estimation is difficult in the presence of texture. These can be onerous requirements; in this paper we propose a graphical model to estimate the illumination ..."
Abstract - Cited by 11 (4 self) - Add to MetaCart
Illuminant estimation from shadows typically relies on accurate segmentation of the shadows and knowledge of exact 3D geometry, while shadow estimation is difficult in the presence of texture. These can be onerous requirements; in this paper we propose a graphical model to estimate the illumination

A Robust Illumination Estimate for Chromatic Adaptation in Rendered Images

by Hendrik P. A. Lensch, Peter-pike Sloan, Er Wilkie, Andrea Weidlich
"... We propose a method that improves automatic colour correction operations for rendered images. In particular, we propose a robust technique for estimating the visible and pertinent illumination in a given scene. We do this at very low computational cost by mostly re-using information that is already ..."
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We propose a method that improves automatic colour correction operations for rendered images. In particular, we propose a robust technique for estimating the visible and pertinent illumination in a given scene. We do this at very low computational cost by mostly re-using information that is already

UNSUPERVISED SIMULTANEOUS REGISTRATION AND EXPOSURE CORRECTION

by Pedro M. Q. Aguiar
"... Early approaches to building mosaics by composing photographic images, assume the input images have similar exposures. Since this is unlikely to happen in practice, it became common to compensate for different exposures in the blending step, after the images have been registered, or aligned [1]. How ..."
Abstract - Cited by 5 (2 self) - Add to MetaCart
simple method to jointly estimate the registration parameters and the parameters describing the exposure correction, directly from the image intensity values. We obtain closedform solutions for the estimates of the exposure parameters. This enables the derivation of a simple two-step iterative algorithm

Robust vision system to illumination changes in a color-dependent task

by Andrés Espínola , Alberto Romay , Tatiana Baidyk , Ernst Kussul
"... Abstract-Most computer vision tasks are strongly sensitive to illumination changes. This is the case of RoboCup competitions, being color dependent tasks, they require a robust color-based segmentation method of the image for object recognition. It is difficult to achieve a constant illumination in ..."
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Abstract-Most computer vision tasks are strongly sensitive to illumination changes. This is the case of RoboCup competitions, being color dependent tasks, they require a robust color-based segmentation method of the image for object recognition. It is difficult to achieve a constant illumination

Thresholding of Badly Illuminated Document Images through Photometric Correction

by Shijian Lu, Chew Lim Tan - ACM DOCENG 2007 , 2007
"... This paper presents a document image thresholding technique that binarizes badly illuminated document images by the photometric correction. Based on the observation that illumination normally varies smoothly and document images often contain a uniformly colored background, the global shading variati ..."
Abstract - Cited by 5 (2 self) - Add to MetaCart
variation is estimated by using a two-dimensional Savitzky-Golay filter that fits a least square polynomial surface to the luminance of a badly illuminated document image. With the knowledge of the global shading variation, shading degradation is then corrected through a compensation process that produces

Robust Estimation of Location

by R. Douglas Martin, Rubenh Zamar, R. D. Martin, Ruben H. Zamar , 1991
"... on paper wassUPIPort,ed Research, contract nUUUl4-In 1964 P. Huber established the following minimax bias robustness result for estimating the location J.L in the e-contamination family F(x) = (1- e)<b[(x- J.L)/8} eH(x) where <b is the standard normal distribution and H is an arbitrary distri ..."
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on paper wassUPIPort,ed Research, contract nUUUl4-In 1964 P. Huber established the following minimax bias robustness result for estimating the location J.L in the e-contamination family F(x) = (1- e)<b[(x- J.L)/8} eH(x) where <b is the standard normal distribution and H is an arbitrary

Automatic robust image registration system: Initialization, estimation, and decision

by Gehua Yang, Charles V. Stewart, Michal Sofka, Chia-Ling Tsai , 2006
"... Our goal is a highly-reliable, fully-automated image registration technique that takes two images and correctly aligns them or decides that they can not be aligned. The technique should handle image pairs having low overlap, variations in scale, large illumination differences (e.g. day and night), s ..."
Abstract - Cited by 1 (1 self) - Add to MetaCart
Our goal is a highly-reliable, fully-automated image registration technique that takes two images and correctly aligns them or decides that they can not be aligned. The technique should handle image pairs having low overlap, variations in scale, large illumination differences (e.g. day and night

Temporally Coded Flash Illumination for Motion Deblurring

by Scott Mccloskey
"... We use temporally sequenced flash illumination to capture coded exposure images of fast-moving objects in low light environments. These coded flash images allow for accurate estimation of blur-free latent images in the presence of object motion. By distributing flashes over a window of time, we less ..."
Abstract - Cited by 1 (0 self) - Add to MetaCart
We use temporally sequenced flash illumination to capture coded exposure images of fast-moving objects in low light environments. These coded flash images allow for accurate estimation of blur-free latent images in the presence of object motion. By distributing flashes over a window of time, we

A Uniform Framework for Estimating Illumination Chromaticity, Correspondence, and Specular Reflection

by Qingxiong Yang, Shengnan Wang, Student Member, Narendra Ahuja, Ruigang Yang
"... Abstract—Based upon a new correspondence matching invariant called illumination chromaticity constancy, we present a new solution for illumination chromaticity estimation, correspondence searching, and specularity removal. Using as few as two images, the core of our method is the computation of a vo ..."
Abstract - Cited by 2 (0 self) - Add to MetaCart
vote distribution for a number of illumination chromaticity hypotheses via correspondence matching. The hypothesis with the highest vote is accepted as correct. The estimated illumination chromaticity is then used together with the new matching invariant to match highlights, which inherently provides
Results 1 - 10 of 185