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In this report three thinning algorithms are developed: one each for use with rectangular, hexagonal, and triangular arrays. The approach to the development of each algorithm is the same. Pictorial results produced by each of the algorithms are presented and the relative performances of the algorithms are compared. It is found that the algorithm operating with the triangular array is the most sensitive to image irregularities and noise, yet it will yield a thinned image with an overall reduced number of points. It is concluded that the algorithm operating in conjunction with the hexagonal array has features which strike a balance between those of the other two arrays. [ABSTRACT FROM AUTHOR]

Examines a technique for recognizing systems of lines in image processing. Decision process used to recognize the input picture of the optimal system of lines; Relationship between the structure of the figure of merit and the complexity of the optimization process; Suitability of the technique for parallel processing.

A method of converting a picture into a "cartoon" S S or map whose regions correspond to differently textured regions is described. Texture edges in the pica hire are detected, and solid regions surrounded by these (usually broken) edges are "colored in" using a propagation process. The resulting map is cleaned by comparing the region colors with the textures of the corresponding regions in the picture, and also by merging some regions with others according to criteria based on topology and size. The method has been applied to the construction of cloud cover maps from cloud cover pictures obtained by satellites. [ABSTRACT FROM AUTHOR]

The article reports on the Moving Image which is considered the eighth art of the twentieth century alongside other older arts such as drama, literature, music, painting and sculpture which originated in the Mediterranean basin. Thomas Alva Edison, Edwin Stanton Porter, and David Wark Griffith are the three American geniuses who created this new means of depicting life. This moving image is seen in theaters, living rooms, drive-ins, museums and classrooms.

Describes an algorithm for producing computer generated half-tone presentations of three-dimensional polygonal surface structures. Advantages over the Warmock algorithm; Comparison of algorithm with computer runs achieved by the Warmock approach; Extension of algorithm to variable position illumination sources.

Digital computers are widely used for the processing of information and data of all kinds, including the pictorial information contained in photographs and other graphical representations. Efficient conversion facilities for puffing graphical information into the computer and retrieving it in graphical form are therefore much needed. One of the most commonly employed devices for obtaining permanent graphical output from digital computers is the microfilm plotter. Regrettably, present models have no provision for producing images with a continuous gray scale or "halftones." In this note several programming techniques are described for obtaining halftone pictures from a microfilm plotter under the control of a digital computer. Illustrative examples of several methods are given. [ABSTRACT FROM AUTHOR]

Any region can be regarded as a union of maximal neighborhoods of its points, and can be specified by the centers and radii of these neighborhoods; this set is a sort of "skeleton" of the region. The storage required to represent a region in this way is comparable to that required when it is represented by encoding its boundary. Moreover, the skeleton representation seems to have advantages when it is necessary to determine repeatedly whether points are inside or outside the region, or to perform set-theoretic operations on regions. [ABSTRACT FROM AUTHOR]

There are situations in the natural sciences and medicine (e.g. in electron microscopy and X-ray photography in which it is desirable to estimate the gray levels of a digital picture at the individual points from the sums of the gray levels along straight tines (projections) at a Few angles. Usually, in such situations, the picture is far from determined and the problem is to find the "most representative" picture. Three algorithms are described (all using Monte Carlo methods which were designed to solve this problem. The algorithms are applicable in a large and varied number of fields. The most important uses may he the reconstruction of possibly asymmetric particles from electron micrographs and three-dimensional X-ray analysis. [ABSTRACT FROM AUTHOR]

A preliminary description of the software for a computer- display system is given with special emphasis on the mane machine interaction. This system is intended for a wide variety of biomedical applications. As an example, the methods are applied to the karyotyping of chromosomes. The system is separated into four programming tasks: picture transformations, file maintenance, picture structuring, and display management. Picture structuring is considered as the vehicle for man-machine communication. A prototype data format for pictures, called a picture-form, is developed. Structure operators are defined which manipulate picture-forms to produce new picture-forms. Many of the ideas are taken from the symbolic mathematical laboratory at MIT conceived by Marvin Minsky. [ABSTRACT FROM AUTHOR]

The article offers information on the introduction of a new department, Graphics and Image Processing, by the journal "Communications of the ACM." William Newman has been appointed as the editor and the department is stated to cover five principal areas. Key areas include hardware and software techniques for producing pictorial output, methodology for the digitization and input of pictorial information, languages and techniques for interacting with graphical systems, methodology for the digital processing and storage of such information, and so on.

Raster scan computer graphics displays with "real time" character generators have previously been limited to alphanumeric characters. A display is described which extends the capabilities of this organization to include general graphics. The feasibility of such a display is shown by deriving the minimum number of patterns required in the read only memory of the character generator to synthesize an arbitrary line. The synthesis process does not compromise picture quality, since the resulting dot patterns are identical with those of a conventional raster display. Furthermore, the time constraints of a raster display are shown to be satisfied for a typical design for very complex line drawings. [ABSTRACT FROM AUTHOR]

Discusses an interactive computer-controlled scanning and display system for pattern recognition and signal processing. Components of the system; Description of the system design and programming support; Application to scanner control, optical character recognition and image processing.

A television-like scanned-display system has been successfully Implemented on a Honeywell DDP424 computer installation. The scanned image is stored in the core memory of the computer, and software scan conversion is used to convert the rectangular coordinates of a point to the appropriate word and bit In an output display array in core storage. Results thus far Indicate that flicker-free displays of large amounts of data are possible with reasonably fast graphical interaction. A scanned Image of size 240 X 254 points is displayed at a 30 frame-per-second rate. [ABSTRACT FROM AUTHOR]

This article presents information on various activities organized by the Association for Computing Machinery (ACM). The Fifth Annual Microprogramming Workshop will be held in the Illini Union of the University of Illinois at Urbana-Champaign on September 25 and 26. Sponsored by the ACM Special Interest Group on Microprogramming and the 555 Computer Society, this workshop provides a leading forum where active workers in the microprogramming area can hear several formal papers and participate in informal discussion groups oriented to specific topics. Professor Daniel L. Slotnick, director of the Center for Advanced Computation at the University of Illinois at Urbana-Champaign, will be the featured speaker at a banquet on September 25; his topic will be "Parallel Processing." The 1973 San Diego Biomedical Symposium will be held January 31 through February 2, 1973, at the Sheraton-Harbor Island Hotel, San Diego, California. The Symposium theme will be "Innovations in Biomedicine." Technical papers appropriate to the following sessions are invited: aids to clinical care, modeling and analysis, interpretation and data reduction, scanning and image processing, information engineering, and general innovations.

The article presents information on the chronology of events related to the field of computer industry. The Association for Computing Machinery will present a program at the AAAS meeting in Washington D.C. in December on "Current Advances Toward Better Computing for Researchers." The Seventh Annual Princeton Conference on Information Sciences and Systems will be held at Princeton University, Princeton, New Jersey, during March 22-23, 1973. Authors are invited to submit papers describing new advances, applications, and ideas in the fields of computer science, communication theory, system and circuit theory including contributions which explore the application of these and related disciplines to current societal issues. The First International Joint Conference on Pattern Recognition will be held from October 30-November 1, 1973, at the Mayflower Hotel in Washington D.C. The conference will cover all aspects of theoretical and applied pattern recognition, including classification theory and complexity, non-parametric methods, image processing, and character recognition.

Raster scan computer graphics with"real time" character generators have previously been limited to alphanumeric characters. A display has been described which extends the capabilities of this organization to include general graphics. Two fundamentally different scan conversion algorithms which have been developed to support this display are presented. One is most suitable to non- interactive applications and the other to Interactive applications. The algorithms were implemented in Fortran on the CDC6400 computer. Results obtained from the implementations show that the non interactive algorithms can significantly reduce display file storage requirements at little cost in execution time over that of a conventional raster display. The interactive algorithm can improve response time and reduce storage requirements. [ABSTRACT FROM AUTHOR]

Optical and digital holography are reviewed. The mathematical model and computational techniques of the authors' digital holographic process are discussed, and applications of computer holography are suggested. Computer holograms have been made of three-dimensional objects which give faithful reconstructions, even in white light. A new approach based on point apertures for the image is discussed. Photographs of the images reconstructed from digital holograms are presented. [ABSTRACT FROM AUTHOR]

The article focuses on the spring Joint Computer Conference that would be organized by Association for Computing Machinery on May 14-16 in Boston, Massachusetts. In this tempestuous age of societal upheaval, reawakening responsibility, and involvement, people everywhere are demanding solutions to, or relief from, the problems which beset the society. Another area the technical program emphasizes is computer graphics. Believed to be of greatest potential as the mechanism for man-machine communication, techniques and applications of computer graphics will be described. It will be pointed out that present hardware and software techniques for its use are being developed in an uncoordinated manner. The result is that communication about the level of achievement and development in computer graphics, particularly software, is poor. Increasingly, the forces, actions, and reactions propagated throughout the land by information processing technology are accelerating in social impact-- for better and for worse. At a panel entitled "URGENT--Increased Dialogue with Society" participants will establish the bases for the need for such discussions and will recommend specific actions to implement the expanded discourse.

The article focuses on the complicated "hidden line problem" in computer graphics which has been solved by Phillipe Loutrel, a graduate student in electrical engineering at the New York University School of Engineering and Science. The problem involved programming a computer to generate perspective drawings of three-dimensional objects and then identify and, if desired, eliminate any edges not visible from a specified vantage point. The solution involves a procedure that enables a computer, in seconds, to generate line drawings of any polyhedron with the "hidden lines" either deleted or shown by dashes. Loutrel cut the calculation time from minutes to seconds by devising techniques that classify and immediately eliminate most of the totally invisible edges and then minimize the testing necessary to identify the remaining hidden edges. Loutrel also extended his technique to handle complex illumination problems. The technique enables computers to calculate what lighted faces of the object would be visible to the observer.