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IBM Journal of Research and Development

Issue 1 • Date Jan. 1987

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Displaying Results 1 - 13 of 13
  • Digital halftoning on the IBM 4250 Printer

    Page(s): 2 - 15
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1597 KB)  

    A method of reproducing high-quality continuous-tone images via the IBM 4250 Printer is presented. The approach is modeled on the halftone process used in conventional lithography but is adapted to discrete bilevel printing and digital processing. We use a combination of standard and novel techniques. These include generation and calibration of a set of halftone dot patterns, randomized error propagation in pattern selection, and resolution enhancement in areas of high intensity gradients. The resultant images have good gray-scale rendition and sharp edges without the problems of contouring and worminess often associated with digital image reproduction. We have named this approach PREPRESS: Picture Rendition using Error Propagation and Resolution Enhancement in Simulated Screening. View full abstract»

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  • Binary-image-manipulation algorithms in the Image View Facility

    Page(s): 16 - 31
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1271 KB)  

    Most current implementations of electronic mail deal primarily with coded information. A scanned-document-handling system that could scan a document, distribute it, display it on terminals, and print it on host-attached printers would offer a similar convenience for documents in hard-copy rather than coded form. For such a system to be practical, fast software is needed for a number of image-manipulation functions. The required functions are compression, to reduce the size of the data files; decompression, to reconstruct the scanned document; scaling, to match the resolution of the scan to the resolution of the display or printer; and rotation, to reorient documents scanned sideways or upside down. This paper describes a collection of algorithms underlying fast software for manipulating binary images that is used in the Image View Facility, a System/370-based software package that permits the display and printing of binary images at various resolutions. View full abstract»

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  • PANDA: Processing Algorithm for Noncoded Document Acquisition

    Page(s): 32 - 43
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1063 KB)  

    With a scanned-document-handling system, documents can be scanned, stored, transmitted to remote locations, viewed on displays and terminals, edited, and printed. These systems hold much promise for office automation, since they facilitate the communication and storage of information that is not easily recoded into the traditional formats for text and graphics. However, most of the current systems that perform these functions are intended for documents that at every point are either black or white, but not gray. These systems effectively exclude documents that contain regions with varying shades of gray (known as continuous-tone regions). PANDA, the Processing Algorithm for Noncoded Document Acquisition, is a technique that processes mixed documents, those that contain continuous-tone regions in addition to text, graphics, and line art. PANDA produces a high-quality binary representation of all regions of a mixed document. Furthermore, all regions of the binary representation, including the continuous-tone image regions, are significantly compressed by the run-length-based compression algorithms that underlie scanned-document-handling systems. This is a key feature of PANDA. Indeed, this compression makes practical the inclusion of mixed documents into many existing systems. View full abstract»

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  • YODA: An advanced display for personal computers

    Page(s): 44 - 57
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1148 KB)  

    YODA (the YOrktown Display Adapter) is an experimental display designed to improve the quality and speed of users' interactions with personal computers. This paper describes the YODA hardware architecture and software design. Special attention is given to techniques used for antialiasing. The various trade-offs and decisions that were made are discussed. View full abstract»

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  • Document convergence in an interactive formatting system

    Page(s): 58 - 72
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1091 KB)  

    One of the most complex aspects of document formatting is the processing of references to remote objects such as headings and figures. In the case of a forward reference to an object that occurs later in the document, two formatting passes are usually needed before the document converges to a stable state. Some documents require more than two passes to converge, and cases are known of documents that never converge but oscillate between two unstable states. This paper describes the techniques used for resolving references and detecting document convergence by the Interactive Composition and Editing Facility, Version 2 (ICEF2). ICEF2 is an interactive formatting system that allows users to move about in a document, editing and reformatting pages. The concepts of formatting pass and document convergence are discussed in the context of interactive formatting. A description is given of the ICEF2 data store, a small relational database manager with special features for detecting document convergence. A sample ICEF2 style definition is discussed to illustrate how ICEF2 deals with document elements whose appearance depends on their location on the page. View full abstract»

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  • LEXX—A programmable structured editor

    Page(s): 73 - 80
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (736 KB)  

    Many sophisticated and specialized editing programs have been developed in recent years. These editors help people manipulate data, but the diversity complicates rather than simplifies computer use. LEXX is an editing program that can work with the syntax and structure of the data it is presenting, yet is not restricted to just one kind of data. It is used for editing programs, documents, and other material and hence provides a consistent environment for the user regardless of the editing task. The new live parsing technique used by LEXX means that it can be programmed to handle a very wide variety of structured data. The structure information is, in turn, used to improve the presentation of data (through color, fonts, and formatting), which makes it easier for people to deal with the text being edited. View full abstract»

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  • A method for efficient storage and rapid application of context-sensitive phonological rules for automatic speech recognition

    Page(s): 81 - 90
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (689 KB)  

    In an automatic speech-recognition system, the application of phonological rules to phonemic strings in order to create phonetic graphs is a computationally time- and storage-consuming process. A great many such graphs must be constructed during the decoding phase; thus it is important to be able to rapidly construct phonetic graphs for strings of words from graphs of individual words. However, because many phonological rules operate across word boundaries or require interword context, it is not possible to determine a unique, context-independent phonetic graph for a word. We describe a method for determining the phonetic graph for a word in isolation, together with auxiliary information to allow phonetic graphs for different words to be rapidly interconnected to form a phonetic graph for a string of words; the method also reduces storage requirements significantly. View full abstract»

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  • Feature analysis for symbol recognition by elastic matching

    Page(s): 91 - 95
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (419 KB)  

    A technique has been developed for the recognition of unconstrained handwritten discrete symbols based on elastic matching against a set of prototypes generated by individual writers. The incorporation of feature analysis with elastic matching to eliminate unlikely prototypes is presented in this paper and is shown to greatly reduce the required processing time without any deterioration in recognition performance. View full abstract»

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  • Drop formation by DOD ink-jet nozzles: A comparison of experiment and numerical simulation

    Page(s): 96 - 110
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1315 KB)  

    This paper presents a comparison of a numerical simulation of drop formation and ejection from a drop-on-demand (DOD) ink-jet nozzle with experimental observations from a particular nozzle-transducer design. In the numerical simulation, first the pressure waves in the transducer chamber are calculated using inviscid compressible flow theory to obtain the pressure history at the inner face of the nozzle plate. Then a viscous momentum integral computation is applied to the nozzle to obtain the velocity history at the outer face of the nozzle plate. Finally, the free surface shape is calculated using finite-difference methods on the one-dimensional equations for an inviscid incompressible free jet with surface tension that uses the nozzle exit velocity history as the driving boundary condition. The computations are compared with drop formation photographs obtained from a particular nozzle-transducer design. Encouraging agreement is obtained, but the numerical model will require added sophistication before detailed agreement can be expected. View full abstract»

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  • DNA vectorgrams: Representation of cancer genes as movements on a 2D cellular lattice

    Page(s): 111 - 119
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (660 KB)  

    A brief introduction introduction to a computer graphics characterization of cancer DNA sequences, as well as other biologically interesting sequences, is presented. The procedure described takes DNA sequences containing n bases and computes n two-dimensional real vectors. When displayed on a planar unit-cellular lattice, these characteristic patterns appear as a “DNA vectorgram,” C(n). Several demonstration plots are provided which indicate that C(n) is sensitive to certain statistical properties of the sequence of bases and allows the human observer to visually detect some important sequence structural properties and patterns not easily captured by traditional methods. The system presented has as its primary focus the fast characterization of the progression of sequence data using an interactive graphics system with several controlling parameters. View full abstract»

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  • Path hierarchies in interconnection networks

    Page(s): 120 - 131
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (987 KB)  

    This paper treats the problem of latency minimization in an interconnection network for a system of N high-performance devices. The networks considered here have data transport separated from control, with the data subnetwork designed so that each network function requires only a single control message, and thus only one contention-resolution delay. For sufficiently large N it is shown that (for an abstract hardware model) minimizing contention delays requires that each message subject to such delays have more than one way of reaching its destination (e.g., via a path hierarchy). The overall approach is discussed in the context of the processor-memory interconnection problem in parallel computing. View full abstract»

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  • Recent papers by IBM authors

    Page(s): 132 - 144
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1078 KB)  

    The information listed here is supplied by the Institute for Scientific Information. Reprints of the papers may be obtained by writing directly to the first author cited. Papers are listed alphabetically by author. View full abstract»

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  • Recent IBM patents

    Page(s): 145 - 148
    Save to Project icon | PDF file iconPDF (294 KB)  
    Freely Available from IEEE

Aims & Scope

The IBM Journal of Research and Development is a peer-reviewed technical journal, published bimonthly, which features the work of authors in the science, technology and engineering of information systems.

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Meet Our Editors

Editor-in-Chief
Clifford A. Pickover
IBM T. J. Watson Research Center