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211
BOULT T.: Separation of reflection components using color and polarization.
- In International Journal of Computer Vision
, 1997
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Example-Based Photometric Stereo: Shape Reconstruction with General . . .
, 2005
"... This paper presents a technique for computing the geometry of objects with general reflectance properties from images. For surfaces ..."
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Cited by 88 (2 self)
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This paper presents a technique for computing the geometry of objects with general reflectance properties from images. For surfaces
Automatic Estimation and Removal of Noise from a Single Image
, 2008
"... Image denoising algorithms often assume an additive white Gaussian noise (AWGN) process that is independent of the actual RGB values. Such approaches cannot effectively remove color noise produced by today’s CCD digital camera. In this paper, we propose a unified framework for two tasks: automatic ..."
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Cited by 61 (3 self)
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Image denoising algorithms often assume an additive white Gaussian noise (AWGN) process that is independent of the actual RGB values. Such approaches cannot effectively remove color noise produced by today’s CCD digital camera. In this paper, we propose a unified framework for two tasks: automatic estimation and removal of color noise from a single image using piecewise smooth image models. We introduce the noise level function (NLF), which is a continuous function describing the noise level as a function of image brightness. We then estimate an upper bound of the real NLF by fitting a lower envelope to the standard deviations of per-segment image variances. For denoising, the chrominance of color noise is significantly removed by projecting pixel values onto a line fit to the RGB values in each segment. Then, a Gaussian conditional random field (GCRF) is constructed to obtain the underlying clean image from the noisy input. Extensive experiments are conducted to test the proposed algorithm, which is shown to outperform state-of-the-art denoising algorithms.
Temporal-Color Space Analysis of Reflection
- JOURNAL OF OPTICAL SOCIETY OF AMERICA A
, 1994
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Colour Image Segmentation: A Survey
, 1994
"... Image segmentation, i.e., identification of homogeneous regions in the image, has been the subject of considerable research activity over the last three decades. Many algorithms have been elaborated for gray scale images. However, the problem of segmentation for colour images, which convey much more ..."
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Cited by 58 (0 self)
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Image segmentation, i.e., identification of homogeneous regions in the image, has been the subject of considerable research activity over the last three decades. Many algorithms have been elaborated for gray scale images. However, the problem of segmentation for colour images, which convey much more information about objects in scenes, has received much less attention of scientific community. While several surveys of monochrome image segmentation techniques were published, similar comprehensive surveys for colour images, to our knowledge, did not emerge. This report
Color reflectance modeling using a polychromatic laser range sensor
- IEEE Trans. PAMI
, 1991
"... Abstract-This paper describes a system for simultaneously measuring the 3-D shape and color properties of objects. Range data are obtained by triangulation over large volumes of the scene, whereas color components are separated by means of a white laser. Details are given concerning the modeling an ..."
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Cited by 55 (8 self)
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Abstract-This paper describes a system for simultaneously measuring the 3-D shape and color properties of objects. Range data are obtained by triangulation over large volumes of the scene, whereas color components are separated by means of a white laser. Details are given concerning the modeling and the calibration of the system for bidirectional reflectance-distribution function measurements. A reflection model is used to interpret the data collected with the system in terms of the underlying physical properties of the target. These properties are the diffuse reflectance of the body material, the Fresnel reflectance of the air-media interface, and the slope surface roughness of the interface. Experimental results are presented for the extraction of these parameters. By allowing the subtraction of highlights from color images and the compensation for surface orientation, spectral reflectance modeling can help to understand 3-D scenes. A practical example is given where a color and range image is processed to yield uniform regions according to material pigmentation.
Deformable shape detection and description via model-based region grouping
- IEEE Transactions on Pattern Analysis and Machine Intelligence
, 2001
"... AbstractÐA method for deformable shape detection and recognition is described. Deformable shape templates are used to partition the image into a globally consistent interpretation, determined in part by the minimum description length principle. Statistical shape models enforce the prior probabilitie ..."
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Cited by 51 (2 self)
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AbstractÐA method for deformable shape detection and recognition is described. Deformable shape templates are used to partition the image into a globally consistent interpretation, determined in part by the minimum description length principle. Statistical shape models enforce the prior probabilities on global, parametric deformations for each object class. Once trained, the system autonomously segments deformed shapes from the background, while not merging them with adjacent objects or shadows. The formulation can be used to group image regions obtained via any region segmentation algorithm, e.g., texture, color, or motion. The recovered shape models can be used directly in object recognition. Experiments with color imagery are reported. Index TermsÐImage segmentation, region merging, object detection and recognition, deformable templates, nonrigid shape models, statistical shape models. 1
Deformable Prototypes for Encoding Shape Categories in Image Databases
- PATTERN RECOGNITION, SPECIAL ISSUE ON IMAGE DATABASES
, 1997
"... We describe a method for shape-based image database search that uses deformable prototypes to represent categories. Rather than directly comparing a candidate shape with all shape entries in the database, shapes are compared in terms of the types of nonrigid deformations (differences) that relate th ..."
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Cited by 47 (2 self)
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We describe a method for shape-based image database search that uses deformable prototypes to represent categories. Rather than directly comparing a candidate shape with all shape entries in the database, shapes are compared in terms of the types of nonrigid deformations (differences) that relate them to a small subset of representative prototypes. To solve the shape correspondence and alignment problem, we employ the technique of modal matching, an information-preserving shape decomposition for matching, describing, and comparing shapes despite sensor variations and nonrigid deformations. In modal matching, shape is decomposed into an ordered basis of orthogonal principal components. We demonstrate the utility of this approach for shape comparison in 2-D image databases.
Determining Reflectance Parameters and Illumination Distribution from a Sparse Set of Images for View-dependent Image Synthesis
- In ICCV01
, 2001
"... A framework for photo-realistic view-dependent image synthesis of a shiny object from a sparse set of images and a geometric model is proposed. Each image is aligned with the 3D model and decomposed into two images with regards to the reflectance components based on the intensity variation of object ..."
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Cited by 46 (5 self)
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A framework for photo-realistic view-dependent image synthesis of a shiny object from a sparse set of images and a geometric model is proposed. Each image is aligned with the 3D model and decomposed into two images with regards to the reflectance components based on the intensity variation of object surface points. The view-independent surface reflection (diffuse reflection) is stored as one texture map. The view-dependent reflection (specular reflection) images are used to recover the initial approximation of the illumination distribution, and then a two step numerical minimization algorithm utilizing a simplified Torrance-Sparrow reflection model is used to estimate the reflectance parameters and refine the illumination distribution. This provides a very compact representation of the data necessary to render synthetic images from arbitrary viewpoints. We have conducted experiments with real objects to synthesize photorealistic view-dependent images within the proposed framework. 1.
Detection of Diffuse and Specular Interface Reflections by Color Image Segmentation
- Int’l J. Computer Vision
, 1996
"... Abstract. We present a computational model and algorithm for detecting diffuse and specular interface reflections and some inter-reflections. Our color reflection model is based on the dichromatic model for dielectric materials and on a color space, called S space, formed with three orthogonal basis ..."
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Cited by 45 (1 self)
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Abstract. We present a computational model and algorithm for detecting diffuse and specular interface reflections and some inter-reflections. Our color reflection model is based on the dichromatic model for dielectric materials and on a color space, called S space, formed with three orthogonal basis functions. We transform color pixels measured in RGB into the S space and analyze color variations on objects in terms of brightness, hue and saturation which are defined in the S space. When transforming the original RGB data into the S space, we discount the scene illumination color that is estimated using a white reference plate as an active probe. As a result, the color image appears as if the scene illumination is white. Under the whitened illumination, the interface reflection clusters in the S space are all aligned with the brightness direction. The brightness, hue and saturation values exhibit a more direct correspondence to body colors and to diffuse and specular interface reflections, shading, shadows and inter-reflections than the RGB coordinates. We exploit these relationships to segment the color image, and to separate specular and diffuse interface reflections and some inter-reflections from body reflections. The proposed algorithm is efficacious for uniformly colored dielectric surfaces under singly colored scene illumination. Experimental results conform to our model and algorithm within the limitations discussed. Keywords: 1.
