OpenRaiser/Intern-Atlas huggingface dataset:
Segmented Shape Descriptions from 3-View Stereo
Authors: Parag Havaldar, Gérard G. Medioni
Venue: ICCV
Year: 1995

We address the recovery of segmented, 3-D descriptions of an object from intensity images. We use three views of an object from slightly different viewpoints as our input. For each image we extract a hierarchy of groups based on proximity, parallelism and symmetry in a robust manner. The groups in the three images are matched by computing the epipolar geometry. For each set of matched groups from the three images, we then label the contours of the groups as "true" or "limb" edges. Using the information about groups, the label associated with their contours and projective properties of subclasses of Generalized Cylinders, we infer the 3-D structure of these groups. The proposed method not only allows robust shape recovery but also produces segmented parts. Our approach can also deal with groups generated as a result of texture or shadows on the object. We present results on real images of moderately complex objects.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
The Illumination-Invariant Recognition of Texture in Color Texture
Authors: Glenn Healey, Lizhi Wang 0006
Venue: ICCV
Year: 1995

We represent texture in a color image using spatial correlation functions defined within and between sensor bands. This representation has been shown to be useful for surface recognition, but the structure of spatial correlation functions depends on the spectral properties of the scene illumination. Using a linear model for surface spectral reflectance with the same number of parameters as the number of classes of photoreceptors, we show that illumination changes correspond to linear transformations of a surface correlation matrix. From this relationship, we derive a distance function for comparing sets of spatial correlation functions that can be used for illumination-invariant recognition. This distance function can be computed efficiently from estimated correlation functions. We demonstrate using a large body of experiments that this distance function can be used for accurate surface recognition in the presence of large changes in illumination spectral distribution.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Statistical Learning, Localization, and Identification of Objects
Authors: Joachim Hornegger, Heinrich Niemann
Venue: ICCV
Year: 1995

This work describes a statistical approach to deal with learning and recognition problems in the field of computer vision. An abstract theoretical framework is provided, which is suitable for automatic model generation from examples, identification, and localization of objects. Both, the learning and localization stage are formalized as parameter estimation tasks. The statistical learning phase is unsupervised with respect to the matching of model and scene features. The general mathematical description yields algorithms which can even treat parameter estimation problems from projected data. The experiments show that this probabilistic approach is suitable for solving 2D and 3D object recognition problems using grey-level images. The method can also be applied to 3D image processing issues using range images, i.e. 3D input data.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Computing Visual Correspondence: Incorporating the Probability of a False Match
Authors: Daniel P. Huttenlocher, Eric W. Jaquith
Venue: ICCV
Year: 1995

We describe a method for computing visual correspondence which employs a formal model of the probability of a false match. This model estimates the chance that the best match for each point could have occurred at random. The model is effective at identifying points in one image for which there is no corresponding point in the other image, as occurs at depth boundaries in stereo and at motion boundaries in optical flow. More generally, the model can be used to identify points where the best match is of poor quality, as occurs in regions of uniform texture. We describe the similarity measure used in the method and present the formal model of a false match. We also show examples of using the method to compute stereo disparity.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Closed-World Tracking
Authors: Stephen S. Intille, Aaron F. Bobick
Venue: ICCV
Year: 1995

A new approach to tracking weakly modeled objects in a semantically rich domain is presented. We define a closed-world as a space-time region of an image sequence in which the complete taxonomy of objects is known, and in which each pixel should be explained as belonging to one of those objects. Given contextual object information, context-specific features can be dynamically selected as the basis for tracking. A context-specific feature is one that has been chosen based upon the context to maximize the chance of successful tracking between frames. Our work is motivated by the goal of video annotation-the semi-automatic generation of symbolic descriptions of action taking place in a contextually-rich dynamic scene. We describe how contextual knowledge in the "football domain" can be applied to closed-world football player tracking and present the details of our implementation. We include tracking results based on hundreds of images that demonstrate the wide range of tracking situations the algorithm successfully handles as well as a few examples of where the algorithm fails.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Mosaic Based Representations of Video Sequences and Their Applications
Authors: Michal Irani, P. Anandan 0001, Steven C. Hsu
Venue: ICCV
Year: 1995

Recently, there has been a growing interest in the use of mosaic images to represent the information contained in video sequences. The paper systematically investigates how to go beyond thinking of the mosaic simply as a visualization device, but rather as a basis for efficient representation of video sequences. We describe two different types of mosaics called the static and the dynamic mosaic that are suitable for different needs and scenarios. We discuss a series of extensions to these basic mosaics to provide representations at multiple spatial and temporal resolutions and to handle 3D scene information. We describe techniques for the basic elements of the mosaic construction process, namely alignment, integration, and residual analysis. We describe several applications of mosaic representations including video compression, enhancement, enhanced visualization, and other applications in video indexing, search, and manipulation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Model-Based Matching of Line Drawings by Linear Combinations of Prototypes
Authors: Michael J. Jones 0001, Tomaso A. Poggio
Venue: ICCV
Year: 1995

We describe a technique for finding pixelwise correspondences between two images by using models of objects of the same class to guide the search. The object models are "learned" from example images (also called prototypes) of an object class. The models consist of a linear combination of prototypes. The flow fields giving pixelwise correspondences between a base prototype and each of the other prototypes must be given. A novel image of an object of the same class is matched to a model by minimizing an error between the novel image and the current guess for the closest model image. Currently, the algorithm applies to line drawings of objects. An extension to real grey level images is discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Structure and Motion Estimation from Dynamic Silhouettes under Perspective Projection
Authors: Tanuja Joshi, Narendra Ahuja, Jean Ponce
Venue: ICCV
Year: 1995

Addresses the problem of estimating the structure and motion of a smooth curved object from its silhouettes observed over time by a trinocular stereo rig under perspective projection. We first construct a model for the local structure along the silhouette for each frame in the temporal sequence. Successive local models are then integrated into a global surface description by estimating the motion between successive time instants. The algorithm tracks certain surface features (parabolic points) and image features (silhouette inflections and frontier points) which are used to bootstrap the motion estimation process. The entire silhouette along with the reconstructed local structure are then used to refine the initial motion estimate. We have implemented the proposed approach and report results on real images.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
3D Human Body Model Acquisition from Multiple Views
Authors: Ioannis A. Kakadiaris, Dimitris N. Metaxas
Venue: ICCV
Year: 1995

We present a novel motion-based approach for the part determination and shape estimation of a human's body parts. The novelty of the technique is that neither a prior model of the human body is employed nor prior body part segmentation is assumed. We present a human body part identification strategy (HBPIS) that recovers all the body parts of a moving human based on the spatiotemporal analysis of its deforming silhouette. We formalize the process of simultaneous part determination and 2D shape estimation by employing the supervisory control theory of discrete event systems. In addition, in order to acquire the 3D shape of the body parts, we present a new algorithm which selectively integrates the (segmented by the HBPIS) apparent contours, from three mutually orthogonal views. The effectiveness of the approach is demonstrated through a series of experiments, where a subject performs a set of movements according to a protocol that reveals the structure of the human body.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
A Robot System that Observes and Replicates Grasping Tasks
Authors: Sing Bing Kang, Katsushi Ikeuchi
Venue: ICCV
Year: 1995

To alleviate the problem of overwhelming complexity in grasp synthesis and path planning associated with robot task planning, we adopt the approach of teaching the robot by demonstrating in front of it. The system has four components: the observation system, the grasping task recognition module, the task translator and the robot system. The observation system comprises an active multibaseline stereo system and a dataglove. The data stream recorded is then used to track object motion; this paper illustrates how complimentary sensory data can be used for this purpose. The data stream is also interpreted by the grasping task recognition module, which produces higher levels of abstraction to describe both the motion and actions taken in the task. The resulting information are provided to the task translator which creates commands for the robot system to replicate the observed task. In this paper we describe how these components work with special emphasis on the observation system. The robot system that we use to perform the grasping tasks comprises the PUMA 560 arm and the Utah/MIT hand.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Annular Symmetry Operators: A Method for Locating and Describing Objects
Authors: Michael F. Kelly, Martin D. Levine
Venue: ICCV
Year: 1995

We present a machine vision system in which segmentation is computed in conjunction with a structural description of objects in the scene. It is assumed that contrast edges capture all relevant object information. The principles which dictate how edge features are grouped to infer objects are based upon detecting SYMMETRICAL ENCLOSING edge configurations. These are detected using ANNULAR OPERATORS applied at multiple scales to edge data which have been extracted at multiple scales from a gray level image. The subsequent grouping of symmetry points results in a set of PARTS which make it possible to identify the LOCATION of objects within an image. These parts are used as a basis for constructing coarse graph-based DESCRIPTORS for the PERCEPTUALLY SIGNIFICANT objects found in the scene. Results are presented to illustrate the method's performance on several images.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
3D Surface Reconstruction from Stereoscopic Image Sequences
Authors: Reinhard Koch
Venue: ICCV
Year: 1995

A stereoscopic scene analysis system for 3-D modeling of objects from stereoscopic image sequences is described. A dense map of 3-D surface points is obtained by image correspondence, object segmentation, interpolation, and triangulation. Emphasis is put on the accurate measurement of image correspondences from grey level images. The surface geometry of each scene object is approximated by a triangular wire-frame which stores the surface texture in texture maps. Sequence processing serves to track camera motion and to fuse surfaces from different view points into a consistent 3-D surface model. From the textured 3-D models, highly realistic image sequences from arbitrary view points can be synthesized using computer graphics techniques.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Towards a Unified IU Environment: Coordination of Existing IU Tools with the IUE
Authors: Charles A. Kohl, Jeffrey J. Hunter, Cynthia L. Loiselle
Venue: ICCV
Year: 1995

Progress in the field of computer vision/image understanding (IU) has long been hampered by the lack of standard software environments for research and application development. The Image Understanding Environment (IUE) is being implemented to provide a freely-distributed standard software environment that is appropriate for a wide range of research and development activities. Nevertheless, we recognize that the IUE will not serve everyone's individual needs and that conversion to the IUE could be an expensive process for many sites. Therefore, we are investing significant effort to make the IUE an open environment that can work in coordination with existing IU systems and tools. This paper introduces the work being performed at Amerinex AI to address the processing and data representation factors involved in this coordination.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Multiscale Detection of Curvilinear Structures in 2D and 3D Image Data
Authors: Thomas Koller, Guido Gerig, Gábor Székely, Daniel Dettwiler
Venue: ICCV
Year: 1995

Presents a novel, parameter-free technique for the segmentation and local description of line structures on multiple scales, both in 2D and in 3D. The algorithm is based on a nonlinear combination of linear filters and searches for elongated, symmetric line structures, while suppressing the response to edges. The filtering process creates one sharp maximum across the line-feature profile and across the scale-space. The multi-scale response reflects local contrast and is independent of the local width. The filter is steerable in both the orientation and scale domains, leading to an efficient, parameter-free implementation. A local description is obtained that describes the contrast, the position of the center-line, the width, the polarity, and the orientation of the line. Examples of images from different application domains demonstrate the generic nature of the line segmentation scheme. The 3D filtering is applied to magnetic resonance volume data in order to segment cerebral blood vessels.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
3D Pose Estimation by Fitting Image Gradients Directly to Polyhedral Models
Authors: Henner Kollnig, Hans-Hellmut Nagel
Venue: ICCV
Year: 1995

Addresses the problem of pose estimation and tracking of vehicles in image sequences from traffic scenes recorded by a stationary camera. In a new algorithm, the vehicle pose is estimated by directly fitting image gradients to polyhedral vehicle models without an edge segment extraction process. The new approach is significantly more robust than approaches that rely on feature extraction because the new approach exploits more information from the image data. We can track vehicles that are partially occluded by textured objects, e.g. foliage, where classical approaches based on edge segment extraction fail. Results from various experiments with real-world traffic scenes are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Hierarchical Statistical Models for the Fusion of Multiresolution Image Data
Authors: Jean-Marc Laferté, Fabrice Heitz, Patrick Pérez, Eric Fabre
Venue: ICCV
Year: 1995

This paper presents a class of nonlinear hierarchical algorithms for the fusion of multiresolution image data in low-level vision. The approach combines nonlinear causal Markov models defined on hierarchical graph structures, with standard bayesian estimation theory. Two random processes defined on simple hierarchical graphs (quadtrees or "ternary graphs") are introduced to represent the multiresolution observations at hand and the hidden labels to be estimated. An optimal algorithm (inspired from the Viterbi algorithm) is developed to compute the bayesian estimates on the hierarchical graph structures. Estimates are obtained within two passes on the graph structure. This algorithm is non-iterative and yields a per pixel computational complexity which is independent of image size. This approach is compared to the multiscale algorithm proposed by (Bouman et al., 1994) for single-resolution image segmentation (that we have extended for multiresolution data fusion).< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
A Unified Approach to Coding and Interpreting Face Images
Authors: Andreas Lanitis, Christopher J. Taylor 0001, Timothy F. Cootes
Venue: ICCV
Year: 1995

Face images are difficult to interpret because they are highly variable. Sources of variability include individual appearance, 3D pose, facial expression and lighting. We describe a compact parametrised model of facial appearance which takes into account all these sources of variability. The model represents both shape and grey-level appearance and is created by performing a statistical analysis over a training set of face images. A robust multi-resolution search algorithm is used to fit the model to faces in new images. This allows the main facial features to be located and a set of shape and grey-level appearance parameters to be recovered. A good approximation to a given face can be reconstructed using less than 100 of these parameters. This representation can be used for tasks such as image coding, person identification, pose recovery, gender recognition and expression recognition. The system performs well on all the tasks listed above.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Head-Eye Calibration
Authors: Mengxiang Li, Demetrios Betsis
Venue: ICCV
Year: 1995

We deal with the calibration problem of an active head-eye system, which consists of a pair of cameras mounted on a head with 13 degrees of freedom. The aim of the calibration is to establish relative positions of different 3D systems: between camera and neck, eye and neck, etc., so that we can keep track of the camera position in a fixed (calibration) reference system as a function of the visual parameters of the head-eye system. We formulate the problem and propose both closed-form and nonlinear optimization approaches to solve it. Experiments were carried out and comparison of results with other algorithms were made on both simulated and real data.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Reflectance Function Estimation and Shape Recovery from Image Sequence of a Rotating Object
Authors: Jiping Lu, Jim Little 0001
Venue: ICCV
Year: 1995

We describe a technique for surface recovery of a rotating object illuminated under a collinear light source (where the light source lies on or near the optical axis). We show that the surface reflectance function can be directly estimated from the image sequence without any assumption on the reflectance property of the object surface. From the image sequence, the 3D locations of some singular surface points are calculated and their brightness values are extracted for the estimation of the reflectance function. We also show that the surface can be recovered by using shading information in two images of the rotating object. Iteratively using the first-order Taylor series approximation and the estimated reflectance function, the depth and orientation of the surface can be recovered simultaneously. The experimental results on real image sequences of both matte and specular surfaces demonstrate that the technique is feasible and robust.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
An Integrated Stereo-Based Approach to Automatic Vehicle Guidance
Authors: Quang-Tuan Luong, Joseph Weber, Daphne Koller, Jitendra Malik
Venue: ICCV
Year: 1995

Proposes a new approach for vision-based longitudinal and lateral vehicle control. The novel feature of this approach is the use of binocular vision. We integrate two modules consisting of a new, domain-specific, efficient binocular stereo algorithm, and a lane marker detection algorithm, and show that the integration results in a improved performance for each of the modules. Longitudinal control is supported by detecting and measuring the distances to leading vehicles using binocular stereo. The knowledge of the camera geometry with respect to the locally planar road is used to map the images of the road plane in the two camera views into alignment. This allows us to separate image features into those lying in the road plane, e.g. lane markers, and those due to other objects which are dynamically integrated into an obstacle map. Therefore, in contrast with the previous work, we can cope with the difficulties arising from occlusion of lane markers by other vehicles. The detection and measurement of the lane markers provides us with the positional parameters and the road curvature which are needed for lateral vehicle control. Moreover, this information is also used to update the camera geometry with respect to the road, therefore allowing us to cope with the problem of vibrations and road inclination to obtain consistent results from binocular stereo.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Determining Wet Surfaces from Dry
Authors: Howard B. Mall Jr., Niels da Vitoria Lobo
Venue: ICCV
Year: 1995

Wet surfaces are ubiquitous in our visual experience. Autonomous machines with vision systems will need to identify wet surfaces from dry. Wet surfaces (especially rough, absorbent ones) appear darker when wet. This paper presents the Lekner and Dorf (1988) model for describing the darkening caused by wetting. We explain how to use this optics model to transform intensity values of a region of an image to make that region appear wet. We also show how the model can be reversed in order to make a wet part of an image appear dry. It is also shown that this technique can be used to identify wet regions. This identification is contrasted with darkening caused by shadows. Comparisons of the gray-level histograms of these real images show the validity of this approach for distinguishing wet surfaces from dry.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>