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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.

A conventional method of removing unwanted background information from radiographic images is to use photographic techniques. An alternative approach is the digital processing of x-ray difference images. This approach offers the advantage over photographic methods in that it permits the performance of nonlinear operations, such as compensation for film characteristics, thus offering greater flexibility in the presentation of x-ray images and greater reliability in their interpretation. This paper describes the features and implementation of a new digital approach and presents experimental results obtained from processing two of sets angiograms.

The high-speed digital computer has contributed to significant progress in the field of optics. One particular area of optics benefiting from this progress is image processing. The purpose of image processing is to aid the human observer in extracting from an image information which has been obscured by some type of degradation The numerous factors which can degrade the quality of an image in an optical system include lens aberrations, poor focus, image motion, turbulence, and diffraction. In general, the problem of obtaining good images in an optical system should be approached by minimizing these factors by careful design and by control of conditions during recording of the image, usually on photographic film. However, there are times when all factors cannot be controlled sufficiently so that the recorded image lacks the required detail for a given application. In the past little could be done in the way of improving the image once it had been recorded. Now, recently developed processing techniques allow the image to be improved after it is recorded. Although there are several different methods by which these improvements can be made, one of the most powerful and flexible utilizes the digital computer. The purpose of this paper is to describe the basic method of processing, the difficulties facing the image processor working on practical problems, and a unique image processing system devised to overcome these difficulties.

Reseachers seeking a histological determination of microscopic specimen morphology face the basic problem of analyzing three-dimensional microscopic specimens with two-dimensional imaging devices. This tedious task can be done at the microscope but reproduction of images in hard copy or digital form entails the loss of depth information. Quantitative measurements must generally be made on 2-D images. Several methods have been proposed and implemented to obtain and display 3-D images. In this paper we discuss an approach combining digital image processing techniques with stereo display techniques. This allows control of image quality and selection of different 3-D characteristics for display.