Search For:

Displaying 1-9 out of 9 total
Single-Image Vignetting Correction
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Yuanjie Zheng, Stephen Lin, Sing Bing Kang
Issue Date:June 2006
pp. 461-468
In this paper, we propose a method for determining the vignetting function given only a single image. Our method is designed to handle both textured and untextured regions in order to maximize the use of available information. To extract vignetting informa...
 
Single-Image Vignetting Correction from Gradient Distribution Symmetries
Found in: IEEE Transactions on Pattern Analysis and Machine Intelligence
By Yuanjie Zheng,Stephen Lin,Sing Bing Kang,Rui Xiao,James C. Gee,Chandra Kambhamettu
Issue Date:June 2013
pp. 1480-1494
We present novel techniques for single-image vignetting correction based on symmetries of two forms of image gradients: semicircular tangential gradients (SCTG) and radial gradients (RG). For a given image pixel, an SCTG is an image gradient along the tang...
 
Estimation of image bias field with sparsity constraints
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Yuanjie Zheng, James C. Gee
Issue Date:June 2010
pp. 255-262
We propose a new scheme to estimate image bias field through introducing two sparsity constraints. One is that the bias-free image has concise representation with image gradients or coefficients of other image transformations. The other constraint is that ...
 
Accurate estimation of pulmonary nodule's growth rate in CT images with nonrigid registration and precise nodule detection and segmentation
Found in: Computer Vision and Pattern Recognition Workshop
By Yuanjie Zheng, C. Kambhamettu, T. Bauer, K. Steiner
Issue Date:June 2009
pp. 101-108
We propose a new tumor growth measure for pulmonary nodules in CT images, which can account for the tumor deformation caused by the inspiration level's difference. It is accomplished with a new nonrigid lung registration process, which can handle the tumor...
 
Single-image optical center estimation from vignetting and tangential gradient symmetry
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Yuanjie Zheng, C. Kambhamettu, S. Lin
Issue Date:June 2009
pp. 2058-2065
In this paper, we propose a method for estimating the optical center of a camera given only a single image with vignetting. This is accomplished by identifying the center of the vignetting effect in the image through an analysis of semicircular tangential ...
 
Single-Image Vignetting Correction
Found in: IEEE Transactions on Pattern Analysis and Machine Intelligence
By Yuanjie Zheng, Stephen Lin, Chandra Kambhamettu, Jingyi Yu, Sing Bing Kang
Issue Date:December 2009
pp. 2243-2256
In this paper, we propose a method for robustly determining the vignetting function given only a single image. Our method is designed to handle both textured and untextured regions in order to maximize the use of available information. To extract vignettin...
 
Single-image vignetting correction using radial gradient symmetry
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Yuanjie Zheng, Jingyi Yu, Sing Bing Kang, Stephen Lin, Chandra Kambhamettu
Issue Date:June 2008
pp. 1-8
In this paper, we present a novel single-image vignetting method based on the symmetric distribution of the radial gradient (RG). The radial gradient is the image gradient along the radial direction with respect to the image center. We show that the RG dis...
 
FuzzyMatte: A computationally efficient scheme for interactive matting
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Yuanjie Zheng, Chandra Kambhamettu, Jingyi Yu, Thomas Bauer, Karl Steiner
Issue Date:June 2008
pp. 1-8
In this paper, we propose an online interactive matting algorithm, which we call FuzzyMatte. Our framework is based on computing the fuzzy connectedness (FC) [20] from each unknown pixel to the known foreground and background. FC effectively captures the a...
 
Lung Nodule Growth Analysis from 3D CT Data with a Coupled Segmentation and Registration Framework
Found in: Computer Vision, IEEE International Conference on
By Yuanjie Zheng, Karl Steiner, Thomas Bauer, Jingyi Yu, Dinggang Shen, Chandra Kambhamettu
Issue Date:October 2007
pp. 1-8
In this paper we propose a new framework to simultaneously segment and register lung and tumor in serial CT data. Our method assumes nonrigid transformation on lung deformation and rigid structure on the tumor. We use the B-Spline-based nonrigid transforma...
 
 1