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An analysis technique for biological shape based on the concept of bending energy has been developed. The technique permits the calculation of the amount of energy (work) that would have to be expended to form typical biological shapes out of a linear, thin-shelled medium. In addition the development of this analysis procedure provides several new results concerning image processing including a sampling theorem for simply connected closed contours and a fast algorithm for calculation of the bending energy.

In image processing of aerial photographs in cartography and of remote sensor data in earth resource surveys, one of the most basic parameters is the elevation of the ground estimated by means of parallax measurements made on stereo pairs of aerial images. In conventional methods, measurement by manual stereocomparators is precise but timeconsuming. Existing automatic stereocomparators do not work well because they use too simple a correlation method to get sufficiently precise measurements. Each of the two corresponding patterns from a stereo pair is so distorted by parallax that the calculated correlation value does not always attain the maximum at the point from which we can obtain the correct parallax. As a result of the present study, it appears that an iterative prediction and correction method can be suitable for the efficient and accurate measurement of elevation from stereo imagery. The conventional methods do not fully utilize the information which is presented in the image itself or is a priori known. The first prediction of elevation is carried out only for well-contrasting parts of the image, which usually means roads, coast, forest edges, etc. Then this prediction is expanded to the neighboring parts, making use of the continuity of elevation. Using a temporary predicted elevation map, one of the stereo pair patterns is modified to lessen the distortion compared with the other pattern. Correction of the elevation map is performed using the correlation values calculated from the modified patterns. This feedback procedure is iterated until no correction is needed. This new method is applied to digitized aerial photographs taken at a height of 3,000 m. Finally, a planned automatic image processing system is explained briefly, consisting of a newly developed scanner which can access every point in a scan field at high positional accuracy.

EG&G, Inc., a leader in the field of photographie data acquisition and analysis for over 25 years, has for the past five years been placing increased emphasis on digital image processing in support of the Field Testing Division of the Los Alamos Scientific Laboratory under AEC Contract No. AT(29–1)1183. During that time, capabilities that originally involved photogrammetric and radiometrie analysis have been augmented to include two-dimensional Fourier frequency analysis and spatial filtering of images. This article describes some of the image processing equipment at EG&G, along with the results obtained using this equipment, and discusses digital holography in greater detail.

A model for image processing proposed earlier is discussed and applied to some optical illusions. A simulation on a computer is provided in an attempt to reach a quantitative level of understanding in the study of visual phenomena.

An approach to image processing is made by means of image scanning with an aperture array. The restoration of one-dimensional linear blur is taken as an example, and methods of designing the aperture array and evaluating its performance are discussed. The quality criterion of restored images with regard to resolution and detection is introduced and applied to the practical system.

The spatial and spectral luminance properties of a cloud's surface are being studied to gather more information about the microphysical processes occurring within the cloud. A real-time, field-implementable image processing system has been developed by the authors to sense and display this luminance information, and is described in this paper. Applications, including the investigation of “crown flash” phenomena, are described.

The state of the art in large-scale digital computers has recently opened the way for high resolution image processing by digital techniques. With the increasing availability of digital image input/output devices it is becoming quite feasible for the average computing facility to embark upon high-quality image restoration and enhancement. The motivation for such processes becomes self evident when one realizes the tremendous emphasis man puts on his visual senses for survival. Considering the relative success achieved in one-dimensional (usually time) signal processing, it is to be expected that far greater strides could be made in the visual two-dimensional realm of signal processing.

A method for the determination of lightness from image intensity is presented. For certain classes of images, lightness corresponds to reflectance, while image intensity is the product of reflectance and illumination intensity. The method is two-dimensional and depends on the different spatial distribution of these two components of image intensity. Such a lightness-judging process is required for Land's retinex theory of color vision, A number of physical models are developed and computer simulation of the process is demonstrated. This work should be of interest to designers of image processing hardward, cognitive psychologists dealing with the human visual system and neurophysiologists concerned with the function of structures in the primate retina.

In recent years there has been an increasing interest in the processing of pictorial images by digital computer. Since the initial success of digital image correction at JPL in support of the space program, considerable effort has been devoted to applying image processing techniques in a wide variety of application areas. This effort has involved the direct spin-off of some basic research results in industrial applications and the utilization of this experience in establishing relevant directions of new image processing research and development.

An interactive computer environment is one which attempts to facilitate the interplay between man and machine in pursuit of a goal defined by man. Presumably, to be effective, this environment should allow the calculating speed, precision, and structured logical/iterative skill of the machine to serve the conceptual, intuitive, highly associative, and contexturally sensitive attributes of human mental function in the solution of problems. Too often the match is obtuse, the goals vague, and the result frustration. Much emphasis ought to be placed on the a priori specific problem oriented knowledge, gained through experience, which the man brings to the machine and wishes to share with it in a versatile but structured way.

Rat liver histological sections were photographed through a Leitz microscope and the negative digitised using a P-1000 Photoscan micro-densitometer (OPTRONICS). In the system the transmitted light through the film was measured using a photo-detector, converted to 256 grey levels, and stored on a 7 track magnetic tape. The optical density was measured every 100 microns. The final picture consisted of 750,000 points. These were fed into a PDP-15/40 computer with core requirements of 24 K words and two 250 K word disks, and analysed. The present paper describes a detailed analysis of one heptocyte.

A brief review of recent advances in the quantitative capabilities of the scanning electron microscope is presented. Special emphasis is placed on scanning transmission electron microscopy, X-ray techniques, secondary ion mass analysis, selected area electron channeling patterns, and image processing techniques. A systems approach to the development of the SEM as a research tool is recommended.

The application of digital image processing techniques to medical problems has been under development at the Jet Propulsion Laboratory, California Institute of Technology, since 1966. The initial research concentrated on medical X-ray films and include (1) image restoration, i.e., using digital techniques to retrieve information partially lost in the imaging system which generated the pictures, (2) image enhancement to emphasize features or remove useless data, and (3) image mensuration to provide more quantitative measurements and analyses than are available through visual inspection techniques. From the initial concern with X-ray image processing, this research in image processing as applied to biomedicine has been expanded to include a system for the automated analysis of images from light and electron microscopes. The Automated Light Microscope System (ALMS), around which the chromosome analysis system has been developed, allows direct scanning of specimen images into a computer for subsequent analysis. The applications of digital image processing to biomedicine at the Jet Propulsion Laboratory encompass 15 separate research projects. The areas selected for discussion in this paper give some indication of the types of picture analysis that are being performed. The current trend in biomedical image processing is toward more human interaction in the research setting.

After an overview of the cellular logic image processor, CLIP 3, parallel algorithms for joining two points are described. These real time algorithms are simple, work properly, preserve the connectivity, are based only on logic, and show much of the behavior of processing occurring in sensory elements of animals.