Showing papers on "Object (computer science) published in 1984"

A semantics of multiple inheritance.

Abstract: There are two major ways of structuring data in programming languages. The first and common one, used for example in Pascal, can be said to derive from standard branches of mathematics. Data are organized as Cartesian products (i.e., record types), disjoint sums (i.e., unions or variant types), and function spaces (i.e., functions and procedures). The second method can be said to derive from biology and taxonomy. Data are organized in a hierarchy of classes and subclasses, and data at any level of the hierarchy inherit all the attributes of data higher up in the hierarchy. The top level of this hierarchy is usually called the class of all objects; every datum is an object and every datum inherits the basic properties of objects, e.g., the ability to tell whether two objects are the same or not. Functions and procedures are considered as local actions of objects, as opposed to global operations acting over objects. These different ways of structuring data have generated distinct classes of programming languages, and induced different programming styles. Programming with taxonomically organized data is often called objectoriented programming, and has been advocated as an effective way of structuring programming environments, data bases, and large systems in general. The notions of inheritance and object-oriented programming first appeared in Simula 67 (Dahl, 1966). In Simula, objects are grouped into classes and classes can be organized into a subclass hierarchy. Objects are similar to records with functions as components, and elements of a class can appear wherever elements of the respective superclasses are expected. Subclasses inherit all the attributes of their superclasses. In Simula, the issues are somewhat complicated by the use of objects as coroutines, so that communication between objects can be implemented as message passing between processes. Smalltalk (Goldberg, 1983) adopts and exploits the idea of inheritance, with some changes. While stressing the message-passing paradigm, a

Data processing system having a memory using object-based information and a protection scheme for determining access rights to such information

Abstract: A digital data processing system has a memory organized into objects containing at least operands and instructions. Each object is identified by a unique and permanent identifier code which identifies the data processing system and the object. The system uses a protection technique to prevent unauthorized access to objects by users who are identified by a subject number which identifies the user, a process of the system for executing a user's procedure, and the type of operation of the system to be performed by the user's procedure. An access control list for each object includes an access control list entry for each subject having access rights to the object and means for confirming that a particular active subject has access rights to a particular object before permitting access to the object. The system also includes stacks for containing information relating to the current state of execution of the system.

Representation and Shape Matching of 3-D Objects

Abstract: A three-dimensional scene analysis system for the shape matching of real world 3-D objects is presented. Various issues related to representation and modeling of 3-D objects are addressed. A new method for the approximation of 3-D objects by a set of planar faces is discussed. The major advantage of this method is that it is applicable to a complete object and not restricted to single range view which was the limitation of the previous work in 3-D scene analysis. The method is a sequential region growing algorithm. It is not applied to range images, but rather to a set of 3-D points. The 3-D model of an object is obtained by combining the object points from a sequence of range data images corresponding to various views of the object, applying the necessary transformations and then approximating the surface by polygons. A stochastic labeling technique is used to do the shape matching of 3-D objects. The technique matches the faces of an unknown view against the faces of the model. It explicitly maximizes a criterion function based on the ambiguity and inconsistency of classification. It is hierarchical and uses results obtained at low levels to speed up and improve the accuracy of results at higher levels. The objective here is to match the individual views of the object taken from any vantage point. Details of the algorithm are presented and the results are shown on several unknown views of a complicated automobile casting.

Tactile Recognition and Localization Using Object Models: The Case of Polyhedra on a Plane

Abstract: This paper discusses how data from multiple tactile sensors may be used to identify and locate one object, from among a set of known objects. We use only local information from sensors: 1) the position of contact points and 2) ranges of surface normals at the contact points. The recognition and localization process is structured as the development and pruning of a tree of consistent hypotheses about pairings between contact points and object surfaces. In this paper, we deal with polyhedral objects constrained to lie on a known plane, i.e., having three degrees of positioning freedom relative to the sensors. We illustrate the performance of the algorithm by simulation.

User Recovery and Reversal in Interactive Systems

Abstract: Interactive systems, such as editors and program development environments, should be explicitly support recovery facilities that permit a user to reverse the effects of past actions and to restore an object to a prior state. A model for interactive systems is presented that allows recovery to be defined precisely and user and system responsibilities to be delineated. Various implementation techniques for supporting recovery are described. Application of a general recovery facility to support reverse execution is discussed. A program development system (called COPE) with extensive recovery facilities, including reverse execution, is described. Keywords: recovery, reverse execution, undo, checkpoint, editor, programming environments.

Advanced video object generator

Abstract: A computer video image generating system including a computer memory having three dimensional object data stored therein employs an advanced object generator for retrieving and processing the object data for output to a span processor for controlling the pixel-by-pixel video output signal for a video display. The advanced object generator includes a translucency processor, an edge-on fading processor, a level of detail blending processor and a bilinear interpolator for texture smoothing.

Editing of a superblock data structure

Abstract: Improvements in an application composite eidtor for compound documents containing not only text but also graphics and tables facilitate the manipulation of object sets in the formatting algorithm The editor works with a page layout philosophy wherein data objects reside on the page and data resides in the data objects All pages reside within a document object, and some data objects may have additional objects within them Objects are data-specific entities that the user can manipulate on the page All objects exist within a specified boundary on the page, and this boundary is defined as an object set boundary Object sets may be moved into positions on the page such that more than one object set is occupying a single displayable are on the page Such an arrangement of objects creates a structure called a superblock A superblock is any displayable area containing two or more object sets positioned so that the object sets overlap one another, reside side-by-side or extend above or below one another A text object set may not be overlapped by any other object set Although the superblock is itself a complex structure, the creation of this structure by the editor greatly simplifies integration of different data types on the page for the user and allows the user to manipulate a group of object sets within a single displayable area on the page with relative ease Moreover, formatting of the document is facilitated by the editor since the superblock is treated as an object set without taking into consideration the complexity inside the superblock structure except when a page end decision must be made

Pattern recognition apparatus

Abstract: A pattern recognition apparatus for recognizing a pattern derived from image data of an outline of an object region is disclosed. The apparatus comprises means for identifying the object region from the input image data, means for extracting outline pixels of the object region, means for polygon-approximating the object region based on a position relationship among the outline pixels to determine vertex coordinates of the approximation polygon, means for determining characteristic data representing a position and an attitude of the region based on the vertex coordinates, and means for superimposing the polygon-approximated object region pattern on a dictionary pattern based on the characteristic data and, determining a common region of the patterns to determine the identity of the patterns. High speed and highly reliable pattern matching is attained.

Vision inspection system

Abstract: A vision inspection system operable with foreground illumination provides user identification of selected regions of a known object for later comparison to an unknown object. A gray scale pixel array of each selected region is processed for edges and this processed data array is stored as a template for each region. Gray scale illumination data from larger corresponding areas of the unknown object are processed for edges to form gradient maps. The first template is iteratively compared to the first gradient map. A correlation value greater than a threshold value causes the system to examine the second and possibly third gradient maps on the unknown object. Distance and angular relationships of the regions are used to both identify and orient the object under test. Once the unknown object is identified and its orientation determined, various visual attributes and measurements of the object can be determined through use of visual tools.

Direct 2-D display of 3-D objects

Abstract: An approach to the problem of deriving a 2-D display of a 3-D object is described that is quite different from previous methods in that boundary detection and hidden-surface removal are not carried out explicitly. The method uses a scan-line representation of three-dimensional objects.

Implicit creation of a superblock data structure

Abstract: An application composite editor for compound documents containing not only text but also graphics and tables to facilitate the manipulation of object sets in the formatting algorithm. The editor works with a page layout philosphy wherein data objects reside on the page and data resides in the data objects. All pages reside within a document object, and some data objects may have additional objects within them. Objects are data-specific entities that the user can manipulate on the page. All objects exist within a specified boundary on the page, and this boundary is defined as an object set boundary. Object sets may be moved into positions on the page such that more than one object set is occupying a single displayable area on the page. Such an arrangement of objects creates a structure called a superblock. A superblock is any displayable area containing two or more objects sets positioned so that the object sets overlap one another, reside side-by-side or extend above or below one another. A text object set may not be overlapped by any other object set. Although the superblock is itself a complex structure, the creation of this structure by the editor greatly simplifies integration of different data types on the page for the user and allows the user to manipulate a group of object sets within a single displayable area on the page with relative ease. Moreover, formatting of the document is facilitated by the editor since the superblock is treated as an object set without taking into consideration the complexity inside the superblock structure except when a page end decision must be made.

Message/Object Programming: An Evolutionary Change in Programming Technology

Abstract: Could a marriage of the message/object model, a la Smalltalk-80, and the operator/operand model, a la Unix, improve the lot of both users and programmers? Stay tuned...

Object management system concepts

Abstract: An office database should be a “total” information resource in that it should be capable of storing data of many arbitrary types. Users of such a system should be able to store conveniently their documents and graphics objects in the same logical storage space as their more traditional records-oriented data.This paper presents a data model that can be used to describe more effectively the objects that occur naturally in the office environment. This model exploits some of the richer semantics of office objects such as the containment of one object within another (e.g., reports contain chapters) and the version histories of objects and their constituent parts. This model forms the basis for our experimental object management system which is used to support the creation of new office application programs.

Flow attribute for text objects

Abstract: Improvements in an application composite editor for compound documents containing not only text but also graphics and tables facilitate the manipulation of object sets in the formatting algorithm. The editor works with a page layout philosophy wherein data objects reside on the page and data resides in the data objects. All pages reside within a document object, and some data objects may have additional objects within them. Objects are data-specific entities that the user can manipulate on the page. All objects exist within a specified boundary on the page, and this boundary is defined as an object set boundary. Object sets may be moved into positions on the page such that more than one object set is occupying a single displayable area on the page. Such an arrangement of objects creates a structure called a superblock. A superblock is any displayable area containing two or more object sets positioned so that the objects sets overlap one another, reside side-by-side or extend above or below one another. A text object set may not be overlapped by any other object set. Although the superblock is itself a complex structure, the creation of this structure by the editor greatly simplifies integration of different data types on the page for the user and allows the user to manipulate a group of object sets within a single displayable area on the page with relative ease. Moreover, formatting of the document is facilitated by the editor since the superblock is treated as an object set without taking into consideration the complexity inside the superblock structure except when a page end decision must be made.

System for recognizing three-dimensional objects

Abstract: A system for recognizing a three-dimensional object includes a plurality of image pickup apparatus, e.g. TV cameras, by which images of the object are picked up from at least three directions. Feature points are extracted from each of at least three images obtained. Two sets of feature points on epipolarly lines are formed which lines are formed on at least two of the images by a feature point on another image. A set of feature points is selected which satisfy a restricting condition determined by the relationship of the image picking-up direction.

Using the Gaussian Image to Find the Orientation of Objects

Abstract: Current three-dimensional vision algorithms can generate depth maps or vector maps from images, but few algorithms extract high-level information from these depth maps. This paper identifies one algorithm that determines an object's orientation by matching object models to depth map data. The object models are constructed by mapping surface orien tation data onto spheres. This process is based on a mathe matical theorem that can be applied only to convex objects, but some extensions for nonconvex objects are presented. The paper shows that a global approach can be used successfully in cases where objects do not touch one another. Another important result illustrates the size of the space of rotations. It shows that even when 6,000 rotations are almost uniformly distributed for matching, errors of 17 degrees are still possible.

Multiprocessor computer system for forming a color picture from object elements defined in a hierarchic data structure

Abstract: A multiprocessor system for forming a color picture from object elements defined in a hierarchic data structure. The object elements are Bezier polygons each of the sides of which forms a Bezier curve. There is provided an array of parallel connected point processors which perform three functions. First of all, from the highest level of the data structure they determine the relevance of each object element to a point in question until either irrelevance is detected or one or more elementary object elements remain. Furthermore, for each point and each relevant elementary object element a binary inside/outside determination is made. Finally, the color is implemented by a priority determination of the elementary object elements determined to be "inside". The inside/outside decision is made in that during successive steps the relevant polygon sides are divided and in that the contribution to the inside/outside determination by the parallelogram diagonalized by the current side portion is decided. The number of intersections of a semi-infinite straight line with respect to the sides of the polygon in question ultimately decides the inside/outside determination.

Surface defect inspecting apparatus

Abstract: The holding mechanism (112) holds an object under inspection in a manner that the substantially entire surface of the object (108) may relatively be scanned by a laser beam. A spherical integrating light collector (127) has an opening (127a) disposed close to the inspected surface of the object (108) held by the holding mechanism (112). A laser beam illuminating mechanism (128) is coupled with the other end of the spherical integrating light collector (127), and illuminates the inspected surface of the object (108) with the laser beam through the opening (127a). A photo-electric converter (129) receives the scattered light as is reflected by the inspected surface and collected by the spherical integrating light collector (127), and converts the scattered light into an electrical signal representing an amount of light. An analog to digital converter (132) converts the electrical signal derived from the photo-electric converter (129) into a digital signal. A peak detector (133) receives the digital signal derived from the analog to digital converter (132) to detect peak values at predetermined periods. A mean value calculator (134) calculates a mean value using a digital signal output from the analog to digital converter (132). A reference value storing memory (141) stores a reference value to determine defects present on the inspected surface of the object (108). A threshold level calculator (140) calculates the threshold level using the reference value and the mean value. A defect detector (137) compares peak values derived from the peak detector (133) with the threshold level, and detects the surface defects on the basis of the result of the comparison.

A generalized object display processor architecture

Abstract: The features and organization of a hardware architecture that is designed to facilitate the real-time display and manipulation of a single three-dimensional object on a raster-scan video display are briefly summarized. The author then outlines the major features of an extension to the architecture that will permit the high-speed display and manipulation of multiple, independent, shaded three-dimensional objects represented as a voxel (volume-element) database with gray scale. The objective is to provide many useful capabilities at or near video rates facilitating extensive real-time interaction. The architecture is highly modular, permitting a cost tradeoff to be made to achieve a given level of performance. It also includes a great deal of regularity in its structure, making it directly suitable for VLSI implementation. A key feature is that no computational operations more complex than adds, shifts, and comparisons are required in real time. The display characteristics for each object are controlled by a concise object descriptor table, which contains all of the control parameters required to process that object.

Pattern matching method and apparatus

Abstract: Disclosed is a pattern matching method and apparatus, in which an object pattern is collated with a master pattern using pattern matching. As a first step, an area corresponding to a master pattern size is sequentially extracted from a master sample image for forming the master pattern, each extracted pattern is collated and the other patterns in the master sample image. An extracted pattern which has a minimum similarity to all the other patterns, and, as a result, shows the most distinctive pattern, is used for the master pattern. Using the present method and apparatus, pattern matching having a higher recognition rate can be performed. Further, using the present pattern matching method, an apparatus can be obtained for positioning the object to be recognized with a highest positioning accuracy.

Top-Down Construction of 3-D Mechanical Object Shapes from Engineering Drawings

Abstract: 32 M any CAD/CAM systems are commercially available today, but there are numerous ways in which they should be made more efficient. Previous research has demonstrated that more efficient methods exist for carrying out operations between objects such as intersection calculations between surfaces. Currently, the man/ machine interface is itself a major obstacle to raising the productivity of CAD/CAM systems.

Natural Language driven Image Generation

Abstract: In this paper the experience made through the development of a NAtural Language driven Image Generation is discussed. This system is able to imagine a static scene described by means of a sequence of simple phrases. In particular, a theory for equilibrium and support will be outlined together with the problem of object positioning.

System for sensing spatial coordinates

Abstract: A system for sensing the spatial position of a moveable object (14) with respect to an energized conductive surface (10,12) whereby the spatial coordinates (x, y) of the object are determined. The system provides a means of accurately measuring the coordinates of the object with respect to a two-dimensional coordinate system independent of the third orthogonal dimension, thereby avoiding significant measurement errors due to variations ofthe object's position in the third orthogonal dimension. The system also ascertains the coordinate (z) of the object in this third dimension, which can then be utilized as an independent control variable in the system. Further, the system can accommodate a number of energized conductive surfaces over which the object may be positioned and can determine the spatial coordinates of the object with respectto any such surface. ln general,the system of the present invention can ascertain the generalized n-tuple position vector of the object with respect to each of a plurality of generalized, energized conductive surfaces. In any of the foregoing forms, the energized conductive surfaces can be transparent.

An architecture for object management in OIS

Abstract: The design of a prototype for an application development environment in OIS (Office Information Systems), OPAL, is outlined. OPAL is based on an object management approach.The paper starts with a short discussion on object oriented systems and some important related concepts including Modularity, Instantiation, Property Inheritance and Subclassing, Active Objects and finally OIS-Modeling Tools.The authors' effort in this direction, OPAL, is based on the PACKET concept, which is the principal data and action structuring device. Programs, data including large data bases, meta-data as well as system defined components are all represented as objects which in turn are implemented as packets. Since all components in the system are considered as objects, it is possible to manage them all in a uniform way which in turn simplifies the system tremendously.

Superblock structure in a multiple in a data editor

Abstract: Improvements in an application composite editor for compound documents containing not only text but also graphics and tables facilitate the manipulation of object sets in the formatting algorithm. The editor works with a page layout philosophy wherein data objects reside on the page and data resides in the data objects. All pages reside within a document object, and some data objects may have additional objects within them. Objects are data-specific entities that the user can manipulate on the page. All objects exist within a specified boundary on the page, and this boundary is defined as an object set boundary. Object sets may be moved into positions on the page such that more than one object set is occupying a single displayable area on the page. Such an arrangement of objects creates a structure called a superblock. A superblock is any displayable area containing two or more object sets positioned so that the object sets overlap one another, reside side-by-side or extend above or below one another. A text object set may not be overlapped by any other object set. Although the superblock is itself a complex structure, the creation of this structure by the editor greatly simplifies integration of different data types on the page for the user and allows the user to manipulate a group of object sets within a single displayable area on the page with relative ease. Moreover, formatting of the document is facilitated by the editor since the superblock is treated as an object set without taking into consideration the complexity inside the superblock structure except when a page end decision must be made.

Object Representation, Identification and Positioning from Range Data

Abstract: We review the types of representations (both single level and hierarchical) and the matching algorithms which have been found useful in the design and implementation of a 3-D vision system that can model, identify, and position industrial parts.

A Syntactic Approach to 3-D Object Representation

Abstract: A 3-D object representation scheme which uses surfaces as primitives and grammatical production rules as structural relationship descriptors is proposed. Possible selections of surface primitives are discussed. Examples are given to illustrate the object description method.

Design Transaction Management

Abstract: A design transaction is a sequence of operations mapping a consistent version of an object into a new version. We describe a mechanism, based on version checkout and change files, that supports controlled sharing and is resilient to crashes in a network of workstations and database servers.