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Displaying 1-50 out of 58 total
Line space gathering for single scattering in large scenes
Found in: ACM Transactions on Graphics (TOG)
By Baining Guo, Kun Zhou, Stephen Lin, Xin Sun, Baining Guo, Kun Zhou, Stephen Lin, Xin Sun, Baining Guo, Kun Zhou, Stephen Lin, Xin Sun, Baining Guo, Kun Zhou, Stephen Lin, Xin Sun
Issue Date:July 2010
pp. 1-10
We present an efficient technique to render single scattering in large scenes with reflective and refractive objects and homogeneous participating media. Efficiency is obtained by evaluating the final radiance along a viewing ray directly from the lighting...
     
Semantically-Based Human Scanpath Estimation with HMMs
Found in: 2013 IEEE International Conference on Computer Vision (ICCV)
By Huiying Liu,Dong Xu,Qingming Huang,Wen Li,Min Xu,Stephen Lin
Issue Date:December 2013
pp. 3232-3239
We present a method for estimating human scan paths, which are sequences of gaze shifts that follow visual attention over an image. In this work, scan paths are modeled based on three principal factors that influence human attention, namely low-level featu...
 
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...
 
A Closed-Form Solution to Retinex with Nonlocal Texture Constraints
Found in: IEEE Transactions on Pattern Analysis and Machine Intelligence
By Qi Zhao,Ping Tan,Qiang Dai,Li Shen,Enhua Wu,Stephen Lin
Issue Date:July 2012
pp. 1437-1444
We propose a method for intrinsic image decomposition based on retinex theory and texture analysis. While most previous methods approach this problem by analyzing local gradient properties, our technique additionally identifies distant pixels with the same...
 
A Prism-Mask System for Multispectral Video Acquisition
Found in: IEEE Transactions on Pattern Analysis and Machine Intelligence
By Xun Cao,Hao Du,Xin Tong,Qionghai Dai,Stephen Lin
Issue Date:December 2011
pp. 2423-2435
This paper presents a prism-mask system for capturing multispectral videos. The system is composed of a triangular prism, a monochrome camera, and an occlusion mask. Incoming light beams from the scene are sampled by the occlusion mask, dispersed into thei...
 
Super resolution using edge prior and single image detail synthesis
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Yu-Wing Tai, Shuaicheng Liu, Michael S. Brown, Stephen Lin
Issue Date:June 2010
pp. 2400-2407
Edge-directed image super resolution (SR) focuses on ways to remove edge artifacts in upsampled images. Under large magnification, however, textured regions become blurred and appear homogenous, resulting in a super-resolution image that looks unnatural. A...
 
Coded exposure imaging for projective motion deblurring
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Yu-Wing Tai, Naejin Kong, Stephen Lin, Sung Yong Shin
Issue Date:June 2010
pp. 2408-2415
We propose a method for deblurring of spatially variant object motion. A principal challenge of this problem is how to estimate the point spread function (PSF) of the spatially variant blur. Based on the projective motion blur model of [27], we present a b...
 
Correction of Spatially Varying Image and Video Motion Blur Using a Hybrid Camera
Found in: IEEE Transactions on Pattern Analysis and Machine Intelligence
By Yu-Wing Tai, Hao Du, Michael S. Brown, Stephen Lin
Issue Date:June 2010
pp. 1012-1028
We describe a novel approach to reduce spatially varying motion blur in video and images using a hybrid camera system. A hybrid camera is a standard video camera that is coupled with an auxiliary low-resolution camera sharing the same optical path but capt...
 
Enhancing Bilinear Subspace Learning by Element Rearrangement
Found in: IEEE Transactions on Pattern Analysis and Machine Intelligence
By Dong Xu, Shuicheng Yan, Stephen Lin, Thomas S. Huang, Shih-Fu Chang
Issue Date:October 2009
pp. 1913-1920
The success of bilinear subspace learning heavily depends on reducing correlations among features along rows and columns of the data matrices. In this work, we study the problem of rearranging elements within a matrix in order to maximize these correlation...
 
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...
 
Image/video deblurring using a hybrid camera
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Yu-Wing Tai, Hao Du, Michael S. Brown, Stephen Lin
Issue Date:June 2008
pp. 1-8
We propose a novel approach to reduce spatially varying motion blur using a hybrid camera system that simultaneously captures high-resolution video at a low-frame rate together with low-resolution video at a high-frame rate. Our work is inspired by Ben-Ezr...
 
Intrinsic image decomposition with non-local texture cues
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Li Shen, Ping Tan, Stephen Lin
Issue Date:June 2008
pp. 1-7
We present a method for decomposing an image into its intrinsic reflectance and shading components. Different from previous work, our method examines texture information to obtain constraints on reflectance among pixels that may be distant from one another...
 
Filtering and Rendering of Resolution-Dependent Reflectance Models
Found in: IEEE Transactions on Visualization and Computer Graphics
By Ping Tan, Stephen Lin, Long Quan, Baining Guo, Harry Shum
Issue Date:March 2008
pp. 412-425
The apparent reflectance of a surface depends upon the resolution at which it is imaged. Conventional reflectance models represent reflection at a single predetermined resolution; however, a low-resolution pixel that views a greater surface area often exhi...
 
Subpixel Photometric Stereo
Found in: IEEE Transactions on Pattern Analysis and Machine Intelligence
By Ping Tan, Stephen Lin, Long Quan
Issue Date:August 2008
pp. 1460-1471
Conventional photometric stereo recovers one normal direction per pixel of the input image. This fundamentally limits the scale of recovered geometry to the resolution of the input image, and cannot model surfaces with subpixel geometric structures. In thi...
 
A Probabilistic Intensity Similarity Measure based on Noise Distributions
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Yasuyuki Matsushita, Stephen Lin
Issue Date:June 2007
pp. 1-8
We derive a probabilistic similarity measure between two observed image intensities that is based on the noise properties of the camera. In many vision algorithms, the effect of camera noise is either neglected or reduced in a preprocessing stage. However,...
 
Element Rearrangement for Tensor-Based Subspace Learning
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Shuicheng Yan, Dong Xu, Stephen Lin, Thomas S. Huang, Shih-Fu Chang
Issue Date:June 2007
pp. 1-8
The success of tensor-based subspace learning depends heavily on reducing correlations along the column vectors of the mode-k flattened matrix. In this work, we study the problem of rearranging elements within a tensor in order to maximize these correlatio...
 
Radiometric Calibration from Noise Distributions
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Yasuyuki Matsushita, Stephen Lin
Issue Date:June 2007
pp. 1-8
A method is proposed for estimating radiometric response functions from noise observations. From the statistical properties of noise sources, the noise distribution for each scene radiance value is shown to be symmetric for a radiometrically calibrated cam...
 
Removal of Image Artifacts Due to Sensor Dust
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Changyin Zhou, Stephen Lin
Issue Date:June 2007
pp. 1-8
Image artifacts that result from sensor dust are a common but annoying problem for many photographers. To reduce the appearance of dust in an image, we first formulate a model of artifact formation due to sensor dust. With this artifact formation model, we...
 
Graph Embedding and Extensions: A General Framework for Dimensionality Reduction
Found in: IEEE Transactions on Pattern Analysis and Machine Intelligence
By Shuicheng Yan, Dong Xu, Benyu Zhang, Hong-Jiang Zhang, Qiang Yang, Stephen Lin
Issue Date:January 2007
pp. 40-51
Over the past few decades, a large family of algorithms—supervised or unsupervised; stemming from statistics or geometry theory—has been designed to provide different solutions to the problem of dimensionality reduction. Despite the different motivations o...
 
Rank-one Projections with Adaptive Margins for Face Recognition
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Dong Xu, Stephen Lin, Shuicheng Yan, Xiaoou Tang
Issue Date:June 2006
pp. 175-181
In supervised dimensionality reduction, tensor representations of images have recently been employed to enhance classification of high-dimensional data with small training sets. To handle tensor data, this approach has been formulated with tight restrictio...
 
Separation of Highlight Reflections on Textured Surfaces
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Ping Tan, Long Quan, Stephen Lin
Issue Date:June 2006
pp. 1855-1860
We present a method for separating highlight reflections on textured surfaces. In contrast to previous techniques that use diffuse color information from outside the highlight area to constrain the solution, the proposed method further capitalizes on the s...
 
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...
 
Separating Reflections in Human Iris Images for Illumination Estimation
Found in: Computer Vision, IEEE International Conference on
By Huiqiong Wang, Stephen Lin, Xiaopei Liu, Sing Bing Kang
Issue Date:October 2005
pp. 1691-1698
A method is presented for separating corneal reflections in an image of human irises to estimate illumination from the surrounding scene. Previous techniques for reflection separation have demonstrated success in only limited cases, such as for uniform col...
 
Determining the Radiometric Response Function from a Single Grayscale Image
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Stephen Lin, Lei Zhang
Issue Date:June 2005
pp. 66-73
A method is presented for computing the radiometric response function of a camera from a single grayscale image. While most previous techniques require a set of registered images with different exposures to obtain response data, our approach capitalizes on...
 
Light Field Morphing Using 2D Features
Found in: IEEE Transactions on Visualization and Computer Graphics
By Lifeng Wang, Stephen Lin, Seungyong Lee, Baining Guo, Heung-Yeung Shum
Issue Date:January 2005
pp. 25-34
We present a 2D feature-based technique for morphing 3D objects represented by light fields. Existing light field morphing methods require the user to specify corresponding 3D feature elements to guide morph computation. Since slight errors in 3D specifica...
 
Real Time Environment Map Interpolation
Found in: Image and Graphics, International Conference on
By Wenle Wang, Lifeng Wang, Stephen Lin, Jianmin Wang, Baining Guo
Issue Date:December 2004
pp. 382-389
Environment mapping, or reflection mapping, has been widely used in the game and movie industries to give objects a realistic illumination atmosphere. For moving objects, direct frame-by-frame calculation of environment maps and correspondence-based interp...
 
Radiometric Calibration from a Single Image
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Stephen Lin, Jinwei Gu, Shuntaro Yamazaki, Heung-Yeung Shum
Issue Date:July 2004
pp. 938-945
Photometric methods in computer vision require calibration of the camera?s radiometric response, and previous works have addressed this problem using multiple registered images captured under different camera exposure settings. In many instances, such an i...
 
Face Alignment Under Variable Illumination
Found in: Automatic Face and Gesture Recognition, IEEE International Conference on
By Yuchi Huang, Stephen Lin, Stan Z. Li, Hanqing Lu, Heung-Yeung Shum
Issue Date:May 2004
pp. 85
This paper presents an approach to face alignment under variable illumination, an obstacle largely ignored in previous 2D alignment work. To account for illumination variation, our method employs two forms of relatively lighting-invariant information. Edge...
 
Multiple-cue Illumination Estimation in Textured Scenes
Found in: Computer Vision, IEEE International Conference on
By Yuanzhen Li, Stephen Lin, Hanqing Lu, Heung-Yeung Shum
Issue Date:October 2003
pp. 1366
In this paper, we present a method that integrates cues from shading, shadow and specular reflections for estimating directional illumination in a textured scene. Texture poses a problem for lighting estimation, since texture edges can be mistaken for chan...
 
Realistic Rendering and Animation of Knitwear
Found in: IEEE Transactions on Visualization and Computer Graphics
By Yanyun Chen, Stephen Lin, Hua Zhong, Ying-Qing Xu, Baining Guo, Heung-Yeung Shum
Issue Date:January 2003
pp. 43-55
<p><b>Abstract</b>—We present a framework for knitwear modeling and rendering that accounts for characteristics that are particular to knitted fabrics. We first describe a model for animation that considers knitwear features and their eff...
 
Lighting Interpolation by Shadow Morphing Using Intrinsic Lumigraphs
Found in: Computer Graphics and Applications, Pacific Conference on
By Yasuyuki Matsushita, Sing Bing Kang, Stephen Lin, Heung-Yeung Shum, Xin Tong
Issue Date:October 2002
pp. 58
Densely-sampled image representations such as the light field or Lumigraph have been effective in enabling photorealistic image synthesis. Unfortunately, lighting interpolation with such representations has not been shown to be possible without the use of ...
 
Multibaseline Stereo in the Presence of Specular Reflections
Found in: Pattern Recognition, International Conference on
By Yuanzhen Li, Stephen Lin, Hanqing Lu, Sing Bing Kang, Heung-Yeung Shum
Issue Date:August 2002
pp. 30573
We address the problem of accurate depth estimation using multibaseline stereo in the presence of specular reflections. Specular reflections can cause the intensity and color of corresponding points to change dramatically according to different viewpoints,...
 
Separation of Diffuse and Specular Reflection in Color Images
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Stephen Lin, Heung-Yeung Shum
Issue Date:December 2001
pp. 341
The presence of specular reflections in images can lead many traditional computer vision algorithms to produce erroneous results. To address this problem, we propose a method based on the neutral interface reflection model for separating the diffuse and sp...
 
An Appearance Representation for Multiple Reflection Components
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Stephen Lin, Sang W. Lee
Issue Date:June 2000
pp. 1105
Variability in object appearance due to illumination conditions has typically been modeled for only diffuse reflection. In this paper, we present a method for determining multiple reflection components for a set of photometric images, and describe a linear...
 
Estimation of Diffuse and Specular Appearance
Found in: Computer Vision, IEEE International Conference on
By Stephen Lin, Sang W. Lee
Issue Date:September 1999
pp. 855
To account for the variability of object appearance due to differences in illumination, attention has recently been focused on representing the set of images for all possible lighting conditions. Approaches that address this problem have primarily focused ...
 
A Representation of Specular Appearance
Found in: Computer Vision, IEEE International Conference on
By Stephen Lin, Sang W. Lee
Issue Date:September 1999
pp. 849
The appearance of an object can vary considerably with changes in illumination conditions. Methods have been developed to describe these differences for diffuse reflection using the Lambertian model, but little work has been done in characterizing specular...
 
Using Chromaticity Distributions and Eigenspace Analysis for Pose, Illumination, and Specularity-Invariant Recognition of 3D Objects
Found in: Computer Vision and Pattern Recognition, IEEE Computer Society Conference on
By Stephen Lin, Sang Wook Lee
Issue Date:June 1997
pp. 426
The distribution of object colors can be effectively utilized for recognition and indexing. Difficulties arise in the recognition of object color distributions when there are variations in illumination color, changes in object pose with respect to illumina...
 
Semantic colorization with internet images
Found in: ACM Transactions on Graphics (TOG)
By Alex Yong-Sang Chia, Ping Tan, Raj Kumar Gupta, Shaojie Zhuo, Siu-Yeung Cho, Stephen Lin, Yu-Wing Tai, Alex Yong-Sang Chia, Ping Tan, Raj Kumar Gupta, Shaojie Zhuo, Siu-Yeung Cho, Stephen Lin, Yu-Wing Tai
Issue Date:December 2011
pp. 1-15
Colorization of a grayscale photograph often requires considerable effort from the user, either by placing numerous color scribbles over the image to initialize a color propagation algorithm, or by looking for a suitable reference image from which color in...
     
Shading-Based Shape Refinement of RGB-D Images
Found in: 2013 IEEE Conference on Computer Vision and Pattern Recognition (CVPR)
By Lap-Fai Yu,Sai-Kit Yeung,Yu-Wing Tai,Stephen Lin
Issue Date:June 2013
pp. 1415-1422
We present a shading-based shape refinement algorithm which uses a noisy, incomplete depth map from Kinect to help resolve ambiguities in shape-from-shading. In our framework, the partial depth information is used to overcome bas-relief ambiguity in normal...
 
Learning the Change for Automatic Image Cropping
Found in: 2013 IEEE Conference on Computer Vision and Pattern Recognition (CVPR)
By Jianzhou Yan,Stephen Lin,Sing Bing Kang,Xiaoou Tang
Issue Date:June 2013
pp. 971-978
Image cropping is a common operation used to improve the visual quality of photographs. In this paper, we present an automatic cropping technique that accounts for the two primary considerations of people when they crop: removal of distracting content, and...
 
Bayesian Depth-from-Defocus with Shading Constraints
Found in: 2013 IEEE Conference on Computer Vision and Pattern Recognition (CVPR)
By Chen Li,Shuochen Su,Yasuyuki Matsushita,Kun Zhou,Stephen Lin
Issue Date:June 2013
pp. 217-224
We present a method that enhances the performance of depth-from-defocus (DFD) through the use of shading information. DFD suffers from important limitations - namely coarse shape reconstruction and poor accuracy on texture less surfaces - that can be overc...
 
Single-Image Reflectance Estimation for Relighting by Iterative Soft Grouping
Found in: Computer Graphics and Applications, Pacific Conference on
By Yuanzhen Li, Stephen Lin, Sing Bing Kang, Hanqing Lu, Heung-Yeung Shum
Issue Date:October 2002
pp. 483
Reflectance values for image-based relighting are often estimated from grouped pixels with similar reflectance, but such groupings are difficult to compute with certainty for sparse image data. To address this problem, we propose an iterative method that a...
 
3D shape regression for real-time facial animation
Found in: ACM Transactions on Graphics (TOG)
By Chen Cao, Kun Zhou, Stephen Lin, Yanlin Weng
Issue Date:July 2013
pp. 1-10
We present a real-time performance-driven facial animation system based on 3D shape regression. In this system, the 3D positions of facial landmark points are inferred by a regressor from 2D video frames of an ordinary web camera. From these 3D points, the...
     
Global illumination with radiance regression functions
Found in: ACM Transactions on Graphics (TOG)
By Baining Guo, Jiaping Wang, Minmin Gong, Peiran Ren, Stephen Lin, Xin Tong
Issue Date:July 2013
pp. 1-12
We present radiance regression functions for fast rendering of global illumination in scenes with dynamic local light sources. A radiance regression function (RRF) represents a non-linear mapping from local and contextual attributes of surface points, such...
     
Image-based clothes animation for virtual fitting
Found in: SIGGRAPH Asia 2012 Technical Briefs (SA '12)
By Bo Shu, Ping Tan, Shaojie Zhuo, Stephen Lin, Xiaoming Deng, Zhenglong Zhou
Issue Date:November 2012
pp. 1-4
We propose an image-based approach for virtual clothes fitting, in which a user moves freely in front of a virtual mirror (i.e., video screen) that displays the user wearing a superimposed virtual garment. The motions and deformations of the virtual garmen...
     
Diffusion curve textures for resolution independent texture mapping
Found in: ACM Transactions on Graphics (TOG)
By Baining Guo, Guofu Xie, Stephen Lin, Weiwei Xu, Wencheng Wang, Xin Sun, Xin Tong, Yue Dong
Issue Date:July 2012
pp. 1-9
We introduce a vector representation called diffusion curve textures for mapping diffusion curve images (DCI) onto arbitrary surfaces. In contrast to the original implicit representation of DCIs [Orzan et al. 2008], where determining a single texture value...
     
Semantic colorization with internet images
Found in: Proceedings of the 2011 SIGGRAPH Asia Conference (SA '11)
By Alex Yong-Sang Chia, Ping Tan, Raj Kumar Gupta, Shaojie Zhuo, Siu-Yeung Cho, Stephen Lin, Yu-Wing Tai
Issue Date:December 2011
pp. 1-137
Colorization of a grayscale photograph often requires considerable effort from the user, either by placing numerous color scribbles over the image to initialize a color propagation algorithm, or by looking for a suitable reference image from which color in...
     
Semantic colorization with internet images
Found in: Proceedings of the 2011 SIGGRAPH Asia Conference (SA '11)
By Alex Yong-Sang Chia, Ping Tan, Raj Kumar Gupta, Shaojie Zhuo, Siu-Yeung Cho, Stephen Lin, Yu-Wing Tai
Issue Date:December 2011
pp. 1-8
Colorization of a grayscale photograph often requires considerable effort from the user, either by placing numerous color scribbles over the image to initialize a color propagation algorithm, or by looking for a suitable reference image from which color in...
     
Line space gathering for single scattering in large scenes
Found in: ACM SIGGRAPH 2010 papers (SIGGRAPH '10)
By Baining Guo, Kun Zhou, Stephen Lin, Xin Sun
Issue Date:July 2010
pp. 10-18
We present an efficient technique to render single scattering in large scenes with reflective and refractive objects and homogeneous participating media. Efficiency is obtained by evaluating the final radiance along a viewing ray directly from the lighting...
     
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