OpenRaiser/Intern-Atlas huggingface dataset:
Direct motion stereo: Recovery of observer motion and scene structure
Authors: Brian Y. Hayashi, Shahriar Negahdaripour
Venue: ICCV
Year: 1990

Using a stereo vision system, the authors show how the translational motion and scene structure can be recovered directly from image gradients and time derivatives. There is no need to estimate or establish correspondences between features across images. The direction of motion is recovered using a procedure which involves minimizing the sum of the squared error of a linear constraint equation over the entire image. The magnitude of the motion is estimated from the stereo disparity. The scene structure is recovered in the form of a depth map using the recovered motion, image gradients, and time derivatives. Experimental results using real images are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Understanding assembly illustrations in an assembly manual without any model of mechanical parts
Authors: Shoujie He, Norihiro Abe, Tadahiro Kitahashi
Venue: ICCV
Year: 1990

A discussion is presented of how to understand assembly illustrations in an assembly manual without basing it on any model of mechanical parts. The discussion is based on the following two basic prerequisites. The first is that at the present stage mechanical parts are assumed to be in the shape of or composed of cylinders. The second is to recognize the 3-D-structure of mechanical parts by using the assembly information obtained from auxiliary lines. A hierarchical approach is developed to understand an assembly illustration. Also presented is a 'generated' structure understanding scheme. The scheme finds the generated structure in the succeeding illustration, by using preliminary information on the generated structure from the current assembly illustration. The preliminary information is obtained by understanding the current assembly illustration.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Simple method for computing 3D motion and depth
Authors: David J. Heeger, Allan D. Jepson
Venue: ICCV
Year: 1990

The nonlinear equation that relates the optical-flow field to 3-D motion and depth can be split by an exact algebraic manipulation to form three sets of equations. The first set relates the image velocities to the translational component of the 3-D motion alone. Thus, the depth and the rotational velocity need not be known or estimated prior to solving for the translational velocity. Once the translation has been recovered, the second set of equations can be used to solve for the rotational velocity. Finally, depth can be estimated with the third set of equations, given the recovered transaction and rotation. The algorithm applies to the general case of arbitrary motion with respect to an arbitrary scene. The authors show that the performance of the algorithm compares quite favorably with other proposed approaches.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Temporally integrated surface reconstruction
Authors: Joachim Heel
Venue: ICCV
Year: 1990

A solution is presented to the problem of obtaining and improving an estimate of the 3-D structure of a scene from a sequence of images. The algorithm, which combines single-frame reconstruction techniques and multiple-frame Kalman filtering, is tested on a variety of real motion image sequences.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Interesting patterns for model-based machine vision
Authors: Jorja G. Henikoff, Linda G. Shapiro
Venue: ICCV
Year: 1990

The author's work builds on D.G. Lowe's (1987) theory of perceptual groupings. Minimal processing is applied to an image to extract edges. The edges are then represented as well-defined two-dimensional patterns that the authors call interesting patterns. No attempt is made to infer three-dimensional structure from the patterns, and they are matched against two-dimensional models which are projections of characteristic views of three-dimensional objects. The patterns are built up from modular building blocks called triples.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
An approach to 3D scene reconstruction from noisy binocular image sequences using information fusion
Authors: Lang Hong, Dragana Brzakovic
Venue: ICCV
Year: 1990

The vision system described reconstructs 3D scenes from sequences of noisy binocular images. First, the system establishes all possible matches between the feature pixels in the first binocular image pair and assigns a confidence value to a possible match. Each possible match is associated with a 3D volume. The possible matches are used to predict projections of associated 3D volumes onto the remaining binocular image pairs. These projections are utilized to limit searches for possible matches. The matches are used to update confidence values using an optimal fusion algorithm. Finally, matched pixels with high confidence values are used to reconstruct a 3D scene.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Region-based reconstruction of an indoor scene using an integration of active and passive sensing techniques
Authors: Junichi Hoshino, Tetsuya Uemura, Isao Masuda
Venue: ICCV
Year: 1990

A region-based reconstruction technique is proposed which simplifies the process of scene reconstruction and increases reliability. Integrating grid coding and intensity image analysis methods, stable regions which make up the skeleton structure of a room (i.e. wall, ceiling, floor, etc.) are extracted. The indoor scene is then reconstructed based on 2-D and 3-D topological relationships. The experimental results show that local errors do not radically alter the topological relationships of detected regions, so robust reconstruction can be achieved.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Determining reflectance parameters using range and brightness images
Authors: Katsushi Ikeuchi, Kosuke Sato
Venue: ICCV
Year: 1990

A method is presented for recovering reflectance parameters of optically rough surfaces from a range and a brightness image, both of which are generated by a range-finder. The reflectance model of an optically rough surface consists of two components, known as Lambertian and specular components and respectively represented as a cosine and a Gaussian function, and contains the following three basic parameters: the Lambertian strength, specular strength, and specular sharpness. An iterative least-squares fitting method is used to obtain these parameters derived from range and brightness images. Assuming all pixels only contain the Lambertian component, the authors fit the Lambertian function to all the data points. Based on the fitting of these results, they use a threshold derived from a sensor model of the range-finder and exclude those pixels lying outside the bounds of this threshold. To examine the convergence of the algorithm, the authors implemented this algorithm and applied it to several synthesized images. Several experiments using real images demonstrated the applicability of the algorithm.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Omni-directional stereo for making global map
Authors: Hiroshi Ishiguro, Masashi Yamamoto, Saburo Tsuji
Venue: ICCV
Year: 1990

A novel imaging method is presented for acquiring an omni-directional view with range information using a single camera. The difficult correspondence problem is solved by tracking each feature in the image sequence in the same manner as in epipolar plane image analysis. Although the equivalent camera distance is not long, the authors can obtain reliable estimates because of the high resolution of the panoramic views. The authors expect the resolution in locating sharp edges to be very fine, up to the resolution of camera rotation, 0.005 degree. A global map making procedure is also proposed which uses omni-directional views at different locations. Omni-directional binocular stereo is used to acquire a path-centered local map with direction-dependent uncertainty. By combining multiple local maps, it is possible to build a more reliable global map. Also explored is the possibility for using the panoramic stereo for map making by a robot.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
MRF model-based segmentation of range images
Authors: Anil K. Jain 0001, Sateesha G. Nadabar
Venue: ICCV
Year: 1990

Consideration is given to the application of Markov random field (MRF) models to the problem of edge labeling in range images. The authors propose a segmentation algorithm which handles both jump and crease edges. The jump and crease edge likelihoods at each edge site are computed using special local operators. These likelihoods are then combined in a Bayesian framework with a MRF prior distribution on the edge labels to derive the a posterior distribution of labels. An approximation to the maximum a posteriori estimate is used to obtain the edge labelings. The edge-based segmentation has been integrated with a region-based segmentation scheme resulting in a robust surface segmentation method.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
3D structure from a monocular sequence of images
Authors: Jean-Luc Jezouin, Nicholas Ayache
Venue: ICCV
Year: 1990

The authors address the following problem: given a camera moving in an unknown environment, they want to obtain a 3-D description of the environment. A unifying approach is presented by deriving a unique formalism to process uniformly different but complementary features, namely points and linear segments. Different concepts for tracking features are given: (1) 2-D tracker-2-D features are tracked using an order one dynamic model for their evolution; (2) 2-D+estimation tracker-3-D fusion of 2-D features is performed recursively, and then the value predicted at time t for these 3-D features is projected at time t+1 onto the camera focal plane and replaces the dynamic model used in the 2-D tracker, allowing the introduction of 3-D information into the 2-D feature tracker without prior knowledge of the environment; and (3) 3-D tracker-the 2-D tracker disappears, and all computations are 3-D. The 3-D tracker combines the simplicity of the 2-D tracker and the efficiency of the 2-D+estimation tracker. A description is given of the mechanisms of fusion that integrate 2-D measurements into an estimate of the feature 3-D parameters. Uncertainties are taken into account through extended Kalman filtering. Feature parametrizations are chosen to simplify the linearization process and ensure numerical stability.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Toward the automatic generation of mathematical morphology procedures using predicate logic
Authors: Hyonam Joo, Robert M. Haralick, Linda G. Shapiro
Venue: ICCV
Year: 1990

A discussion is presented of the design of a system that can input a vision task specification and use its knowledge of the operations of mathematical morphology to automatically construct a procedure that can execute the task. To do this, the authors develop a predicate calculus representation to describe the essence of the states of all the images that are created during the execution of the morphological procedure and the states of the relationships among them. The authors translate the English descriptions of morphological procedures into predicate logic. In so doing they gain an understanding of the goal of each procedure and the exact conditions under which a procedure achieves its goal. With this knowledge of the operations of mathematical morphology represented in predicate logic, a search procedure can be used to automatically produce vision procedures.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Hypothesizing and testing geometric attributes of image data
Authors: Kenichi Kanatani
Venue: ICCV
Year: 1990

A general formalism for detecting geometric configurations of image data is presented. The author first estimates an ideal geometric configuration that supposedly exists, and then checks to what extent the original edges must be displaced in order to support the hypothesis. All types of tests are reduced to computing a single measure of edge displacement which provides a universal measure of uncertainty applicable to all types of decision-making.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
On the extensive reconstruction of Hough transform
Authors: Hiroyasu Koshimizu, Munetoshi Numada
Venue: ICCV
Year: 1990

The authors introduce four conditions required by the family of extended Hough transform (EHT) functions, and a few basic examples such as the Hough-parabolic function are presented. Furthermore, two kinds of fast transform functions, the piecewise-linear and fast incremental Hough transforms (PLHT and FIHT), are proposed in order to show the practical usefulness of EHTs. After the definitions and basic properties such as computing cost reduction are briefly presented, it is shown that the line detector based on the EHT function can provide more flexible sensitivity for the angle of the line pattern segments.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Sensitivity of the pose refinement problem to accurate estimation of camera parameters
Authors: Rakesh Kumar 0001, Allen R. Hanson
Venue: ICCV
Year: 1990

A study is made of the effect of errors in estimates of the image center and focal length on pose refinement and other related (3-D inference from 2-D images) problems/algorithms. The authors show that for 'small' field of view imaging systems, incorrect knowledge of the camera center does not affect the determination of the location of the camera significantly. Incorrect estimates of the focal length only significantly affect the determination of the z-component (i.e. parallel to the optical axis) of the translation in camera coordinates. The output of the pose refinement algorithm is used to calculate the relative orientation between the coordinate frames of the same camera in two or more different positions as a prelude to computation of 3-D depths of new points by pseudo-triangulation. A model of error for this depth based on the amount of error in placing the image center conforms to the errors obtained for experiments with synthetic and real data. New points are located to an average accuracy of 1.5 mm and 0.3 ft for the two real image sequences respectively.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Object recognition using a feature search strategy generated from a 3D model
Authors: Yoshinori Kuno, Yasukazu Okamoto, Satoshi Okada
Venue: ICCV
Year: 1990

A vision system is presented which automatically generates an object recognition strategy from a 3D model, and recognizes the object using this strategy. In this system, the appearances of an object from various viewpoints are described with visible 2D features, such as parallel lines and ellipses. Then, the features in the appearances are ranked according to the number of viewpoints from which they are visible. The rank and the feature extraction cost for each feature are considered to generate a tree-like strategy graph. It shows an efficient feature search order when the viewpoint is unknown, starting with commonly occurring features and ending with features specific to a certain viewpoint. The system searches for features in the order indicated by the graph. After detection, the system compares the line representation generated from the 3D model and the image features to localize the object.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Matching range images of human faces
Authors: John C. Lee, Evangelos E. Milios
Venue: ICCV
Year: 1990

The problem of matching range images of human faces for the purpose of establishing a correspondence between similar features of two faces is addressed. Distinct facial features correspond to convex regions of the range image of the face, which is obtained by a segmentation of the range image based on the sign of the mean and Gaussian curvature at each point. Each convex region is represented by its extended Gaussian image, a 1-1 mapping between points of the region and points on the unit sphere that have the same normal. Several issues are examined that are associated with the difficult problem of interpolation of the values of the extended Gaussian image and its representation. A similarity measure between two regions is obtained by correlating their extended Gaussian images. To establish the optimal correspondence, a graph matching algorithm is applied. It uses the correlation matrix between convex regions of the two faces and incorporates additional relational constraints that account for the relative spatial locations of the convex regions in the domain of the range image.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Segmentation as the search for the best description of the image in terms of primitives
Authors: Ales Leonardis, Alok Gupta, Ruzena Bajcsy
Venue: ICCV
Year: 1990

A paradigm is presented for the segmentation of images into piecewise continuous patches. Data aggregation is performed via model recovery in terms of variable-order bivariate polynomials using iterative regression. All the recovered models are candidates for the final description of the data. Selection of the models is achieved through a maximization of the quadratic Boolean problem. The procedure can be adapted to prefer certain kinds of descriptions (one which describes more data points, or has smaller error, or has a lower order model). A fast optimization procedure for model selection is discussed. The approach combines model extraction and model selection in a dynamic way. Partial recovery of the models is followed by the optimization (selection) procedure where only the best models are allowed to develop further. The results are comparable with the results obtained when using the selection module only after all the models are fully recovered, while the computational complexity is significantly reduced. The procedure was tested on real range and intensity images. >
Reconstruction without discontinuities
Authors: Stan Z. Li
Venue: ICCV
Year: 1990

Discontinuities have been important in visual reconstruction to avoid oversmoothing. The article raises the question as to whether location of discontinuities is necessary in this process. The author proposes a class of adaptive regularizers (ARs) for reconstruction in the framework of regularization, in an attempt to solve the conflict between 'oversmoothing across discontinuities' and 'finding discontinuities'. The proposal differs from existing methods in the way it controls continuity, in which true discontinuities are considered in the mathematical sense only. A simple analog neuron-like circuit for hardware implementation is suggested. Experimental results are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
A new transform for curve detection
Authors: Ping Liang
Venue: ICCV
Year: 1990

A novel transform for curve detection, called the curve fitting Hough transform (CFHT), is proposed. In the conventional Hough transform (HT) and its variants, both storage and computation grow exponentially with the number of parameters. The CFHT is advantageous over the conventional HT and its variants in its high speed, small storage, arbitrary parameter range and high parameter resolution. This is achieved by fitting a segment of the curve to be detected to a small neighborhood of edge points. If the fitting error is less than a given tolerance, the parameters obtained from curve fitting are used to map an edge element to a single point in the parameter space. A multidimensional ordered parameter list is used to accumulate the presences of the curve to be detected. Most entries in the parameter list are 'useful' entries in the sense that they represent actual presences of the curves to be detected. Experimental results are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Detecting height from constrained motion
Authors: Xueyin Lin, Zhigang Zhu 0001
Venue: ICCV
Year: 1990

A novel method called height from motion (HFM) is developed to estimate the motion and structure under planar motion. By using this method both translational and rotational motion (three degrees of freedom) can be treated in a unified manner. Based on the HFM method, the correspondence problem becomes easy to deal with, especially under translational motion. Experiments of real scene image sequences and the error analysis (theoretically and experimentally) have shown the efficiency and robustness of the method.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Shape from texture: the homogeneity hypothesis
Authors: Constantinos Marinos, Andrew Blake 0001
Venue: ICCV
Year: 1990

The authors show how a maximum likelihood estimator can be constructed for homogeneous texture. The estimator turns out to be strikingly simple. It simply enforces, iteratively, coincidence of the centroid of the observed elements with the centroid of the imaging window. Whereas the estimator is based on first moments, error bounds are obtained, the authors show, from second moments. Experiments indicate that, for real textures, orientation estimates fall well inside predicted bounds.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Multispectral constraints for optical flow computation
Authors: Vishal Markandey, Bruce E. Flinchbaugh
Venue: ICCV
Year: 1990

Multispectral constraints are exploited for optical flow computation. The theoretical basis and conditions for using multispectral images are described. An optical flow algorithm using multispectral constraints is outlined. Tests of the algorithm on real image sequences show that various multispectral constraints from the visible and infrared spectrum can be used to compute optical flow fields in the presence of noise.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Segmentation of optical flow and 3D data for the interpretation of mobile objects
Authors: Aimé Meygret, Monique Thonnat
Venue: ICCV
Year: 1990

The detection of mobile 3-D objects using both stereovision and motion information is considered. First, the authors present an optical flow estimation method based on a multiresolution technique for the matching of contour chain points. Then an algorithm of segmentation of the chains using the continuity of the gradient of the apparent velocity is described. A similar algorithm is developed for stereo vision: the segmentation of the chains is performed in function of their 2-D proximity and the continuity of their disparity. These two segmentations are then used to interpret the scene in terms of isolated rigid or deformable objects. Results are shown for two complex real road scenes.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>