Scheduled System Maintenance:
Some services will be unavailable Sunday, March 29th through Monday, March 30th. We apologize for the inconvenience.
By Topic

Pattern Analysis and Machine Intelligence, IEEE Transactions on

Issue 11 • Date Nov 1989

Filter Results

Displaying Results 1 - 12 of 12
  • The history heuristic and alpha-beta search enhancements in practice

    Publication Year: 1989 , Page(s): 1203 - 1212
    Cited by:  Papers (24)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (892 KB)  

    Many enhancements to the alpha-beta algorithm have been proposed to help reduce the size of minimax trees. A recent enhancement, the history heuristic, which improves the order in which branches are considered at interior nodes is described. A comprehensive set of experiments is reported which tries all combinations of enhancements to determine which one yields the best performance. In contrast, previous work on assessing their performance has concentrated on the benefits of individual enhancements or a few combinations. The aim is to find the combination that provides the greatest reduction in tree size. Results indicate that the history heuristic combined with transposition tables significantly outperforms other alpha-beta enhancements in application-generated game trees. For trees up to depth 8, this combination accounts for 99% of the possible reductions in tree size, with the other enhancements yielding insignificant gains View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • CAGD-based computer vision

    Publication Year: 1989 , Page(s): 1181 - 1193
    Cited by:  Papers (54)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1308 KB)  

    The authors explore the connection between CAGD (computer-aided geometric design) and computer vision. A method for the automatic generation of recognition strategies based on the 3-D geometric properties of shape has been devised and implemented. It uses a novel technique to quantify the following properties of features which compose models used in computer vision: robustness, completeness, consistency, cost, and uniqueness. By utilizing this information, the automatic synthesis of a specialized recognition scheme, called a strategy tree, is accomplished. Strategy trees describe, in a systematic and robust manner, the search process used for recognition and localization of particular objects in the given scene. The consist of selected 3-D features which satisfy system constraints and corroborating evidence subtrees which are used in the formation of hypotheses. Verification techniques, used to substantiate or refute these hypotheses are explored. Experiments utilizing 3-D data are presented View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Image computations on meshes with multiple broadcast

    Publication Year: 1989 , Page(s): 1194 - 1202
    Cited by:  Papers (26)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (860 KB)  

    The authors consider a mesh-connected processor array with broadcast, in which the processors in each row and in each column can access a shared bus. This computation model is an abstraction of commercially available parallel machines such as the distributed array processor (DAP). The authors show efficient data movement using the buses, which leads to significantly faster solution times for several image problems compared to those on an ordinary mesh-connected array. For several problems, the time performance is comparable to that on the pyramid of corresponding size. Alternate parallel organizations with broadcast feature are also shown. Utilizing the broadcast feature on the arrays can lead to significant improvement of the time performance of many image computations View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Recognizing 3-D objects using surface descriptions

    Publication Year: 1989 , Page(s): 1140 - 1157
    Cited by:  Papers (58)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1744 KB)  

    The authors provide a complete method for describing and recognizing 3-D objects, using surface information. Their system takes as input dense range date and automatically produces a symbolic description of the objects in the scene in terms of their visible surface patches. This segmented representation may be viewed as a graph whose nodes capture information about the individual surface patches and whose links represent the relationships between them, such as occlusion and connectivity. On the basis of these relations, a graph for a given scene is decomposed into subgraphs corresponding to different objects. A model is represented by a set of such descriptions from multiple viewing angles, typically four to six. Models can therefore be acquired and represented automatically. Matching between the objects in a scene and the models is performed by three modules: the screener, in which the most likely candidate views for each object are found; the graph matcher, which compares the potential matching graphs and computes the 3-D transformation between them; and the analyzer, which takes a critical look at the results and proposes to split and merge object graphs View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Determination of three-dimensional object location and orientation from range images

    Publication Year: 1989 , Page(s): 1158 - 1167
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1044 KB)  

    A technique for determining the distortion parameters (location and orientation) of general three-dimensional objects from a single range image view is introduced. The technique is based on an extension of the straight-line Hough transform to three-dimensional space. It is very efficient and robust, since the dimensionality of the feature space is low and since it uses range images directly (with no preprocessing such as segmentation and edge or gradient detection). Because the feature space separates the translation and rotation effects, a hierarchical algorithm to detect object rotation and translation is possible. The new Hough space can also be used as a feature space for discriminating among three-dimensional objects View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A globally convergent algorithm for minimizing over the rotation group of quadratic forms

    Publication Year: 1989 , Page(s): 1228 - 1232
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (340 KB)  

    The authors describe a numerical procedure for solving problems involving minimization over the rotation group of quadratic forms which arise in connection with problems of computer vision. The algorithm presented is a sequential quadratic programming method which takes advantage of the special structure of the problem constraints. It is demonstrate that the method is globally convergent View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Using perceptual organization to extract 3D structures

    Publication Year: 1989 , Page(s): 1121 - 1139
    Cited by:  Papers (81)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1800 KB)  

    The authors describe an approach to perceptual grouping for detecting and describing 3-D objects in complex images and apply it to the task of detecting and describing complex buildings in aerial images. They argue that representations of structural relationships in the arrangements of primitive image features, as detected by the perceptual organization process, are essential for analyzing complex imagery. They term these representations collated features. The choice of collated features is determined by the generic shape of the desired objects in the scene. The detection process for collated features is more robust than the local operations for region segmentation and contour tracing. The important structural information encoded in collated features aids various visual tasks such as object segmentation, correspondence processes, and shape description. The proposed method initially detects all reasonable feature groupings. A constraint satisfaction network is then used to model the complex interactions between the collations and select the promising ones. Stereo matching is performed on the collations to obtain height information. This aids in further reasoning on the collated features and results in the 3-D description of the desired objects View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Stereo correspondence through feature grouping and maximal cliques

    Publication Year: 1989 , Page(s): 1168 - 1180
    Cited by:  Papers (73)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1220 KB)  

    The authors propose a method for solving the stereo correspondence problem. The method consists of extracting local image structures and matching similar such structures between two images. Linear edge segments are extracted from both the left and right images. Each segment is characterized by its position and orientation in the image as well as its relationships with the nearby segments. A relational graph is thus built from each image. For each segment in one image as set of potential assignments is represented as a set of nodes in a correspondence graph. Arcs in the graph represent compatible assignments established on the basis of segment relationships. Stereo matching becomes equivalent to searching for sets of mutually compatible nodes in this graph. Sets are found by looking for maximal cliques. The maximal clique best suited to represent a stereo correspondence is selected using a benefit function. Numerous results obtained with this method are shown View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A real time sectional image measuring system using time sequentially coded grating method

    Publication Year: 1989 , Page(s): 1225 - 1228
    Cited by:  Papers (2)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB)  

    A real-time sectional image measuring system is developed using the time-sequentially-coded grating method, and its application to automatic 3D image data measuring systems is studied. A PLZT electron shutter array is used to project time-sequentially-coded grating patterns on the object. The sectional image is calculated from deformed grating images which are picked up by a TV camera. This system takes about 530 ms to project the 100-slit time-sequentially-coded grating patterns and about 30 ms to calculate one sectional image View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Shape description with a space-variant sensor: algorithms for scan-path, fusion, and convergence over multiple scans

    Publication Year: 1989 , Page(s): 1217 - 1222
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (624 KB)  

    The authors discuss three algorithms related to the blending of a single scene from multiple frames acquired from a space-variant sensor. Given a series of space-variant contour-based scenes with different fixation points, they show how to fuse these into a single multiscan view, which incorporates the information present in the individual scans. They demonstrate an (attentional) algorithm which recursively examines the current knowledge of the scene in order best to choose the next fixation point in terms of focusing attention on regions of maximum boundary curvature. They discuss a simple metric for evaluating convergence over a scan path. This may be used to compare the performance of various attentional algorithms. They discuss their work in light of both machine and biological vision View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A hitherto unnoticed singularity of scale-space

    Publication Year: 1989 , Page(s): 1222 - 1224
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (328 KB)  

    A hitherto unnoticed singularity of scale space occurs only at isolated points in scale space. Thus it does not generically occur for single images, but it can occur occasionally in members of time sequences (say). It occurs at those critical points of the image at which the Laplacean of the illuminance vanishes (a nongeneric condition). The structure of scale space in an infinitesimal neighborhood of such a singularity is explored. The effect of the singularity of mappings between copies of an image at different levels of resolution is evaluated and checked with a numerical calculation View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A curvature-based approach to terrain recognition

    Publication Year: 1989 , Page(s): 1213 - 1217
    Cited by:  Papers (12)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (448 KB)  

    The authors describe an algorithm which uses a Gaussian and mean curvature profile for extracting special points on terrain and then use these points for recognition of particular regions of the terrain. The Gaussian and mean curvatures are chosen because they are invariant under rotation and translation. In the Gaussian and mean curvature image, the points of maximum and minimum curvature are extracted and used for matching. The stability of the position of those points in the presence of noise and with resampling is investigated. The input for this algorithm consists of 3-D digital terrain data. Curvature values are calculated from the data by fitting a quadratic surface over a square window and calculating directional derivatives of this surface. A method of surface fitting which is invariant to coordinate system transformation is suggested and implemented. The algorithm is tested with and without the presence of noise, and its performance is described View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

The IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI) is published monthly. Its editorial board strives to present most important research results in areas within TPAMI's scope.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
David A. Forsyth
University of Illinois