Showing papers on "Image processing published in 1975"

Theory and application of digital signal processing

Abstract: sprightly style and is interesting from cover to cover. The comments, critiques, and summaries that accompany the chapters are very helpful in crystalizing the ideas and answering questions that may arise, particularly to the self-learner. The transparency in the presentation of the material in the book equips the reader to proceed quickly to a wealth of problems included at the end of each chapter. These problems ranging from elementary to research-level are very valuable in that a solid working knowledge of the invariant imbedding techniques is acquired as well as good insight in attacking problems in various applied areas. Furthermore, a useful selection of references is given at the end of each chapter. This book may not appeal to those mathematicians who are interested primarily in the sophistication of mathematical theory, because the authors have deliberately avoided all pseudo-sophistication in attaining transparency of exposition. Precisely for the same reason the majority of the intended readers who are applications-oriented and are eager to use the techniques quickly in their own fields will welcome and appreciate the efforts put into writing this book. From a purely mathematical point of view, some of the invariant imbedding results may be considered to be generalizations of the classical theory of first-order partial differential equations, and a part of the analysis of invariant imbedding is still at a somewhat heuristic stage despite successes in many computational applications. However, those who are concerned with mathematical rigor will find opportunities to explore the foundations of the invariant imbedding method. In conclusion, let me quote the following: "What is the best method to obtain the solution to a problem'? The answer is, any way that works." (Richard P. Feyman, Engineering and Science, March 1965, Vol. XXVIII, no. 6, p. 9.) In this well-written book, Bellman and Wing have indeed accomplished the task of introducing the simplicity of the invariant imbedding method to tackle various problems of interest to engineers, physicists, applied mathematicians, and numerical analysts.

Apparatus for image manipulation

Abstract: An image can be represented by an M × N array I(*,*) of image points, where each point I(i,j) over the ranges 0≦i

The importance of phase in image processing filters

Abstract: We demonstrate that phase accuracy is extremely important in image processing filters and express the hope that more work will be done on the development of filter design techniques which use phase as well as magnitude specifications.

Picture processing and digital filtering

Abstract: Two-Dimensional transforms.- Two-dimensional nonrecursive filters.- Two-dimensional recursive filtering.- Image enhancement and restoration.- Noise considerations in digital image processing hardware.- Recent advances in picture processing and digital filtering.

Application of ERTS images and image processing to regional geologic problems and geologic mapping in northern Arizona

Abstract: The author has identified the following significant results. Computer image processing was shown to be both valuable and necessary in the extraction of the proper subset of the 200 million bits of information in an ERTS image to be applied to a specific problem. Spectral reflectivity information obtained from the four MSS bands can be correlated with in situ spectral reflectance measurements after path radiance effects have been removed and a proper normalization has been made. A detailed map of the major fault systems in a 90,000 sq km area in northern Arizona was compiled from high altitude photographs and pre-existing published and unpublished map data. With the use of ERTS images, three major fault systems, the Sinyala, Bright Angel, and Mesa Butte, were identified and their full extent measured. A byproduct of the regional studies was the identification of possible sources of shallow ground water, a scarce commodity in these regions.

Fourier spectrum of halftone images

Abstract: An analytic expression has been developed that can be used for computing the Fourier spectrum of any halftone image as a function of the original continuous-tone image and the halftone process. This result takes into account the nonlinear effects of the threshold step in the halftone process. Although the result is general and can be applied to any original image, in some cases of periodic images the Fourier components of the halftone image are particularly easy to compute. We show important differences between spectra of halftone images and scanned or sampled images. In halftone images, significant image detail is maintained at spatial frequencies greater than half of the screen frequency and aliasing or moire patterns depend upon object contrast and upon the halftone function differently from similar patterns which occur in scanned or sampled imagery.

On the Measurement of Curvature in a Quantized Environment

Abstract: Some aspects of the application of the mathematical concept of curvature as a practical descriptor of shape for pattern recognition and image processing applications are investigated.

Method and apparatus for form removal from contour compressed image data

Abstract: An apparatus for removing form (background) information from an image for data compression; and for adding the form information during reconstruction of the image. Each object in an image is compressed by contour following of the exterior and interior borders of the object, and encoded in chain link form. Each object in the image as it is compressed is correlated with the appropriate object in the form image by comparing the encoded objects with the already stored encoded objects of the form. If there is a match, the image object which matches the form is deleted from the compressed image. Since the order in which the objects are encountered is known, it is only necessary to correlate each image object with at most a single form object. The correlation includes comparing the starting points of the contour information, the perimeter of the object (the length of its border chain) and the object area. The comparisons are made within a predetermined acceptable tolerance. If the variable image data overlaps some of the form image data, the object is retained in the compressed image. During reconstruction of the image, the form and image data are combined using a technique similar to logical OR operation.

Nonlinear filtering in coherent optical systems through halftone screen processes.

Abstract: Nonlinear filtering operations can be performed in coherent optical systems with the help of the halftone screen process. Theoretical and practical considerations regarding this type of system are presented. The use of these methods to achieve logarithmic filtering is emphasized. Applications to separation of multiplicative signals and noise, speckle noise reduction, and processing of radiographic images are considered. Experimental results are presented.

Image restoration by singular value decomposition.

Abstract: We demonstrate by a computer simulation example that singular value decomposition is a powerful tool for restoring noisy linearly degraded images. We also discuss a way of reducing the computation time requirement.

Partially coherent image processing by laser scanning

Abstract: We describe a class of image-processing optical systems, based on a laser scanner, whose output is an electronic video signal from a simple photodetector. We show that certain image-processing properties of these systems are exactly equivalent to the properties of conventional, partially coherent, image-processing optical systems. These systems are of interest when we want to combine optical image processing with further electronic processing. Some applications, such as electronic read out of phase-encoded images, are discussed.

Iterative Image Restoration

Abstract: The projection method of solving a set of linear equations was used to restore linearly degraded images. The advantages of this method are that it always converges, it can readily make use of a priori information about the image, and it does not need excessive computation time. Experimental results indicate that this method could potentially achieve superresolution.

Image Data Processing by Hadamard-Haar Transform

Abstract: A hybrid version of the Haar and Walsh-Hadamard transforms (HT and WHT) called Hadamard-Haar transform (HHT),is defined and developed. Efficient algorithms for fast computation of the (HHT), and its inverse are developed. (HHT)r is applied to digital signal and image processing and its utility and effectiveness are compared with other discrete transforms on the basis of some standard performance criteria.

System to effect digital encoding of an image

Abstract: A system wherein an image such as, for example, unscreened artwork is divided into sub-images each of which is digitized and is then represented by the digital code of a pattern that closely matches the sub-image. Thereafter, the image is reconstructed by reproducing the pattern equivalents of the sub-images to form a composite image.

Parallel Image Processing

Abstract: Parallel image processing shows certain general similarities to retinal processing and shares with optical computing the characteristics of parallelism. Simulation on digital serial computers (DSC's), although possible in the simpler cases, very soon becomes almost uncontrollable, requiring large memories and very long programming and execution times. Advances in present circuit technology now permit one to construct large arrays of interconnected parallel ogic elements resulting in real-time parallel machines where the action of a statement is simultaneous on all the points of the array. A typical processor of this kind is briefly described and an introduction to its code is given. Examples of symmetrical and directional functions and parallel algorithms are also presented. Possible applications of such processors in image processing, pattern recognition, and artificial intelligence are briefly discussed.

On the cepstrum of two-dimensional functions (Corresp.)

Abstract: Cepstral analysis has been used in speech processing for some time, but in the field of image processing very little attention has been paid to it. Some properties of the two-dimensional cepstrum (especially those absent in the one-dimensional) appear to make it an important tool in image processing. In this correspondence these properties are summarized. Applications to image deblurring (blur identifying) and image classification are mentioned as some possible uses.

Image processing techniques in astronomy

Abstract: By reading, you can know the knowledge and things more, not only about what you get from people to people. Book will be more trusted. As this image processing techniques in astronomy, it will really give you the good idea to be successful. It is not only for you to be success in certain life you can be successful in everything. The success can be started by knowing the basic knowledge and do actions.

Automated Video-Angiocardiographic Image Analysis

Abstract: This paper describes a hardware-software system for handling the two main groups of cardiological data: a) physiological variables such as voltages, pressures, etc., and b) morphological data, derived from x-ray images or angiocardiograms, such as dimensions, areas, or volumes. We will concentrate in particular on some aspects of automated image processing–i. e., the analysis of the size, shape, and contraction pattern of the ventricles from video-angiocardiograms.

Machine processing of remotely sensed data

Abstract: The purpose of the Symposium was an in-depth presentation of new results in the theory, technology, and application of computer processing of remotely sensed data. In addition to the regular papers published in full, there are also included titles and abstracts of the short papers presented. The Symposium topics were: analysis algorithms, clustering feature selection, analysis techniques for forest and agricultural applications, water resources, image processing, computer systems, monitoring and evaluation of natural resources, and land use and geologic applications. (JSR)

Digital Image Registration Method Using Boundary Maps

Abstract: A new method of automatic image registration (matching) is presented. It requires that the original single or multichannel images first be converted to binary boundary maps having elements equal to zero or unity. The method corrects for both translational and rotational errors.

Animated video image display system and method

Abstract: System and method for producing an animated image of a moving object on a video display screen wherein digital data for a plurality of progressively different images of the object is stored in a memory and read out during successive frames of the picture. The data from the memory is combined with data corresponding to the position at which the image of each frame is to be displayed on the screen, and the images are displayed in accordance with the combined image and location data. Background of the Invention

A boundary finding algorithm and its applications

Abstract: An algorithm for locating gray level and/or texture edges in digitized pictures is presented. The algorithm is based on the concept of hypothesis testing. The digitized picture is first subdivided into subsets of picture elements, e.g., 2 \times 2 arrays. The algorithm then compares the first- and second-order statistics of adjacent subsets; adjacent subsets having similar first- and/or second-order statistics are merged into blobs. By continuing this process, the entire picture is segmented into blobs such that the picture elements within each blob have similar characteristics. The boundaries between the blobs comprise the boundaries. The algorithm always generates closed boundaries. The algorithm was developed for multispectral imagery of the earth's surface. Application of this algorithm to various image processing techniques such as efficient coding, information extraction (terrain classification), and pattern recognition (feature selection) are included.

Image enhancement method and apparatus

Abstract: Combined optical and electronic apparatus provide for various types of image enhancement by producing two images of the same scene which differ by a predetermined property, and by electronically subtracting the images to yield a video difference signal which emphasizes or deemphasizes a predetermined characteristic of the scene at which the apparatus is pointed. Various types of image enhancement are obtained by simultaneous scanning of the images produced by two imaging systems in which a relative difference in properties between the images such as deliberate misalignment, optical density difference, image resolution, image magnification or image receptor displacement is introduced to create a particular type of enhancement. The intensities from pairs of scanned spots are subtracted on a point-by-point basis to yield a video difference signal which when displayed provides an image enhanced in a particular manner. Property differences are in general introduced in the aperture plane, at the optics or in the image plane. The subject system can be arranged for edge enhancement, size discrimination, emphasis of lines in a predetermined direction, peripheral image enhancement, and central image or boresite enhancement. This system is particularly useful in clutter rejection for TV-based target tracking systems.

Automated radar data processing system

Abstract: An automated radar data processing system comprised of signal processing cuitry and programmed general purpose digital computer apparatus performs detection, classification and tracking of all targets within the field of view of the radar The signal processing circuitry includes an adaptive video processor which receives the raw radar video signals and which derives a threshold from the noise, clutter, or electronic countermeasures signals in the immediate vicinity of the target and passes only those incoming signals which satisfy the detection criteria in terms of signal to noise ratio and extent The signal processing circuitry is interactive with target track data derived and stored in the computer apparatus, so that the specific signal processing applied to any target by the adaptive video processor is optimized in accordance with the track status of that target The proposed system also better enables a human operator to take a system management position wherein he can set up or establish data processing conditions so as, for example, to optimize target detection in highly variable or critical environments

Digital image restoration under a regression model

Abstract: In this paper, image-restoration techniques based upon a regression model are analyzed and verified by computer simulation. A regression model is formulated to describe image blurring, additive noise, physical image sampling, and quadrature representation. Classical estimation methods utilized for image restoration are described and related to one another. Restorations obtained by these classical techniques are shown to be poor because of noise disturbances and the ill conditioning of the image-degradation regression model. Constrained restoration methods which avoid ill conditioning problems are introduced. Computer simulations demonstrate that a boundedness constraint on the brightness of a reconstructed image provides significantly improved restorations as compared to unconstrained methods.

Image Descriptors for Displays

Abstract: : This report summarizes our experimental and theoretical results on the perception of displayed information. This research is concerned with four issues: (1) the effect of color on pattern recognition. (2) the measurement of statistical estimates for luminance and chrominance information in pictorial scenes, (3) the relationship between perceived changes in image sharpness resulting from changes in display modulation transfer, and (4) the development of a unified display descriptor to model the perception of both luminance and chrominance information. In this report we present the results of a series of experiments that established the relationship between our sharpness descriptor, the visual capacity, and the subjective sharpness of displayed images. The just-noticeable difference (jnd) in image sharpness was measured as a function of display bandwidth. At high spatial frequencies these measurements were found to be in excellent agreement with the assertion that display sharpness is mediated by the perceived rms gradient content of an image: a quantity proportional to the square root of the visual capacity. The addition of chrominance information to a black-and-white image was not found to appreciably affect the perception of image sharpness. Finally, the measured results on the subjective sharpness for both pictorial images and single-transition luminance edges proved to be indistinguishable. We feel that this result supports the contention that edge transitions are important in determining image sharpness in pictorial scenes.