Showing papers on "Image processing published in 1972"

Bayesian-Based Iterative Method of Image Restoration

Abstract: An iterative method of restoring degraded images was developed by treating images, point spread functions, and degraded images as probability-frequency functions and by applying Bayes’s theorem. The method functions effectively in the presence of noise and is adaptable to computer operation.

A Class of Algorithms for Fast Digital Image Registration

Abstract: The automatic determination of local similarity between two structured data sets is fundamental to the disciplines of pattern recognition and image processing. A class of algorithms, which may be used to determine similarity in a far more efficient manner than methods currently in use, is introduced in this paper. There may be a saving of computation time of two orders of magnitude or more by adopting this new approach. The problem of translational image registration, used for an example throughout, is discussed and the problems with the most widely used method-correlation explained. Simple implementations of the new algorithms are introduced to motivate the basic idea of their structure. Real data from ITOS-1 satellites are presented to give meaningful empirical justification for theoretical predictions.

Restoring with Maximum Likelihood and Maximum Entropy

Abstract: Given M sampled image values of an incoherent object, what can be deduced as the most likely object? Using a communication-theory model for the process of image formation, we find that the most likely object has a maximum entropy and is represented by a restoring formula that is positive and not band limited. The derivation is an adaptation to optics of a formulation by Jaynes for unbiased estimates of positive probability functions. The restoring formula is tested, via computer simulation, upon noisy images of objects consisting of random impulses. These are found to be well restored, with resolution often exceeding the Rayleigh limit and with a complete absence of spurious detail. The proviso is that the noise in each image input must not exceed about 40% of the signal image. The restoring method is applied to experimental data consisting of line spectra. Results are consistent with those of the computer simulations.

Image processing in the context of a visual model

Abstract: A specific relationship between some of the current knowledge and thought concerning human vision and the problem of controlling subjective distortion in processed images are reviewed.

Infrared imaging system

Abstract: A pair of scanning mirror systems scans an object image in two dimensions over an infrared detector. The detector signal and signals proportional to the position of the mirror systems permit display of an image of the object on a video monitor. The video monitor display includes a portion thereof which is an image of the object and another portion thereof which is a temperature profile curve of the infrared intensity across one line of the image. A memory is optionally employed to store a frame of video information and to replay it at a much faster rate than it is scanned in order to form a persistent image on the video monitor. Automatic brightness control circuitry adjusts the displayed signal level according to the maximum temperature of the object being imaged.

A Simple Approach to Digital Signal Processing

Abstract: From the Publisher: Digital signal processing (DSP) has been a very active area of research and application for over thirty years Applications range from audio and video electronics to sensors, image processing and medical applications Provides a basic introduction and simple overview of DSP

Grid coding: A novel technique for image processing

Abstract: The encoding of information as the modulation of a grid is explored as the means for allowing the extraction of relevant details or features from images. A major aspect of this approach is the replacement of the heuristics in certain image processing tasks by simple Fourier filtering. Specific examples and particular implementations of coding schemes are described in order to show the wide applicability of the concept. The examples chosen fall in the domains of scene analysis, difference extraction from successive images, automatic extraction of range, extraction of features such as planes, recording of three-dimentional imagery, and the processing of a single coded view to give a set of stereo related pairs.

Real Time Optical Processing with Bi(12)SiO(20), PROM.

Abstract: Use of the Itek PROM, a Pockels effect real time electrooptic image modulator, in optical processing systems is discussed. Applications include an incoherent-to-coherent converter for word/character recognition systems; on-line Vander Lugt type Fourier plane filters for real time cross correlation; a block data composer for holographic memories; and an active storage array for a parallel optical digital computer.

Video detection system

Abstract: An apparatus and method are provided for automatically detecting a change in an image field such as the appearance of an object in said field or the disappearance of said object. The apparatus which employs a television camera scanning the image field and which generates a video picture signal which is applied to a remote cathode ray tube to provide an image of the field on the screen thereof, may be employed for security purposes to automatically detect images in the image field. An alarm is sounded when one or more particular portions of the image field vary in content.

Multispectral data sensor and display system

Abstract: Apparatus is disclosed for displaying images derived from image sensors sensitive to radiation of different spectral bands In an illustrative embodiment of this invention, a first sensor is responsive to radiation in the visible band, whereas a second sensor is responsive to radiation images in the infrared (IR) band; video signals derived from the first and second sensors are displayed upon a suitable display device such as a color cathode tube (CRT) In accordance with the teachings of this invention, the video signals from the first sensor are processed and applied to the color CRT to provide a black and white display image in the absence of a video signal from the second sensor The video signal derived from the second sensor is processed and applied to the color CRT to display the sensed infrared image in various visual colors (or wave-lengths of radiation) dependent upon whether the portions of the viewed infrared image are ''''warmer'''' or ''''cooler'''' than a preselected reference point For example, warmer objects within the viewed scene may be displayed as red, whereas cooler objects may be displayed as blue or green Suitable gain control is associated with the video signal derived from second sensor to insure that the presentation of the color image upon the CRT is independent of the visual video signal derived from the first sensor In an illustrative embodiment of this invention, a DC signal is derived indicative of the amplitude of the first video signal and is used to control the gain of the IR video signal

Analysis method and apparatus utilizing color algebra and image processing techniques

Abstract: A method and apparatus for analyzing an illuminated subject. In the preferred embodiment, the subject is a stained blood cell. A first signal is produced which represents a first predetermined wavelength band of the subject modified illumination at a region in the subject. A second signal is produced which represents a second predetermined wavelength band of the subject modified illumination at the region. The two wavelength bands are selected to produce differential contrast between at least two different regions in the subject. The two signals are algebraically combined with thresholding to classify the subject region in at least one of a predetermined number of categories. Further, signal processing is employed to compile partial and complete features for each region or cell.

Recent developments in digital image processing at the image processing laboratory at the jet propulsion laboratory

Abstract: Image processing of spacecraft images has been carried on at the Jet Propulsion Laboratory since 1964. The most recent advances in removal of geometric distortion and residual image effects along with various types of mapping projections are covered. The recent applications of image processing to the areas of bio-medicine, forensic sciences, and astronomy are discussed. These treatments are of a tutorial nature and should serve as a guide to more complete discussions on the subjects.

Variance measurements by a coherent optical method, with application to image processing.

Abstract: A procedure for measuring the point-to-point local variance of a spatial random scene is discussed. The relations that are required between the second-order statistics of the random process and the parameters of the optical configuration to furnish accurate and stable variance estimates are established. The procedure is experimentally verified by using calibrated samples of the random checkerboard and the overlapping circular grain models. A modification of the procedure enables the generation of spatial masks that are useful in automatic image processing. The spatial masks are used as binary spatial gates to isolate certain classes of objects within a scene and reject all others. Typical masks are synthesized and their applications illustrated.

Image quality rating system

Abstract: The sharpness of definition of an image on film may be automatically determined by comparing an original image on film with a perturbation of the same image formed from the original image. Such perturbation is achieved by using a hologram deblurring filter upon which the original image is projected. A photodetector is used to measure the power spectral density first of the original image, then of the deblurred image. As one criterion of the evaluation, the readings from the photodetector are compared and if the original image has a lower amount of high frequency content that the deblurred image then the original image is not a sharp image. If the original image has a substantially larger amount of high frequency content that the deblurred image then the original image is a sharp image.

Passive image stabilization system

Abstract: An image tracking sensor system mounted to an inertial platform generates an analog image displacement signal for passive image stabilization of a scene image viewed from the platform. A radiometric signal having a frequency proportional to the relative motion between the scene image and a reticle is generated by the convolution of the image with the reticle. This signal is detected and electronically processed in a DC squareroot amplifier, a threshold decision logic and an analog to digital converter which generates a digital signal related to image velocity. The digital signal is measured by a digital differential analyzer doppler frequency comparator which generates digital signals defining image velocities relative to boresight. These digital velocities are integrated and displacements accumulated in a digital up-down counter tracking register. The accumulated displacements represent changes of image position relative to boresight. The accumulated digital displacements are read out of the tracking register by means of a digital to analog converter. An analog image displacement signal generated by the digital to analog converter is applied to the inertial platform for gyro-torquing stabilization control thereof.

An experimental laboratory for pattern recognition and signal processing

Abstract: An interactive computer-controlled scanning and display system has been in operation at the IBM Thomas J. Watson Research Center for three years. The system includes two flying-spot scanners and a TV camera specially interfaced to a process control digital computer, dot-mode and vector displays, analog input and output facilities, and a variety of other experimental equipment. The system design and programming support are described and typical applications in scanner control, optical character recognition, and image processing are presented.

Data Compression and Enhancement of Sampled Images

Abstract: A two-dimensional sampled image can be represented by an equal number of spatial frequencies in the Fourier domain. However, due to physical limitations of the sampling process, there exists an effective cutoff frequency beyond which no information is preserved. The knowledge of this cutoff frequency is very important, since a considerable amount of additional noise can be introduced by frequency components above this cutoff. Availability of a sharp edge within the image allows, within the linear theory, the estimation of the transfer function of the digitizing process itself. This calculated transfer function may be used for image enhancement below the cutoff frequency. In addition, significant amount of data compression may be achieved by removing all spatial frequency terms above the cutoff frequency. An example of this technique is developed utilizing a tribar resolution chart sampled at 1024 x 1024 points.

Multi-channel optical correlator system

Abstract: A multi-channel optical correlation system employs non-coherent light to illuminate a mask having a plurality of linearly disposed channels, each of which has recorded information defined by variations in opacity along its linear length. The non-coherent light source is modulated as a function of an unknown input signal and an image of the illuminated mask is formed in a selected image plane. The transmitted image is swept along the axes of the linearly disposed channels in synchronism with the time period of the unknown input signal and means is provided for temporally integrating the light intensity of the swept image along the linear length of each channel. A peak intensity of illumination within any of the channels of the resultant integrated image of the mask at the image plane indicates substantial correlation of the input signal with the recorded information in that particular channel.

Some new techniques for processing remotely obtained images by self-generated spectral masks.

Abstract: An extension of a new technique that enables parallel, simultaneous processing of remotely obtained images is presented. The technique holds out promise for automatic on-board classification of data. The central feature involves the generation of binary masks, directly from the image, based on object reflectance data, that groups objects into equivalence classes. These masks, called equivalence class masks, can be used in various logical combinations to isolate classes of objects with a priori known reflectance or radiance signatures. Experimental verification of the technique is furnished for simple scenes. A computational scheme, based on a sequence of integrated irradiance measurements on the image, that enables the identification of objects within an equivalence class is suggested.

Ratched Filter Restoration Of Coded-Gamma And X-Ray Imagery

Abstract: Recent work has stimulated considerable interest in using radar pulse compression concepts to improve the quality of medical X-ray and gamma ray photographs. (Refs. 1 and 2) These techniques involve using a coded point spread function to obtain increased resolution and reduced ex posure time. The coded point spread function allows use of a larger aperture in the X-ray camera, but requires a post-detection processing step in order to decode the data and obtain the desired image. The point spread function must be coded in such a anner that its two-dimensional autocorrelation function is very sharply peaked. In the post-detection pro cessing; the coded data are cross-correlated with the chosen point spread function to obtain the desired image.

Computer Interactive Picture Processing

Abstract: : The report describes work done in image processing using an interactive computer system. Techniques for image differencing are described and examples using images returned from Mars by the Mariner Nine spacecraft are shown. Also described are techniques for stereo image processing. Stereo processing for both conventional camera systems and the Viking 1975 Lander camera system is reviewed. (Author)

Two-dimensional shift array of magnetic bubbles and its application to pattern processing

Abstract: Using 52 μm thick TmFeO 3 orthoferrite plate and 1.2 μm thick permalloy film, we realized a two-dimensional shift array of magnetic bubbles on which any two-dimensional pattern can be shifted in a horizontal or vertical direction. This functional array utilizing the shift nature and array processable characteristics of magnetic bubbles suggests the possibility of functional devices for pattern processing. As an example of these functional devices, we propose the pattern rotating memory which can be applied to preprocessing in pattern recognition. We verified the feasibility of this idea by means of computer simulation.

Video signal processing system and method with above-white-level noise inversion

Abstract: This disclosure depicts method and apparatus for processing a television video signal, particularly for processing a noiseadulterated video signal as developed by synchronous-type video detectors. The disclosed method and apparatus involves sensing in a video signal developed by a synchronous-type video detector noise components having amplitude levels exceeding a predetermined reference level above a level which corresponds to a maximum white video display. A modified video signal is developed for supply to the luminance controls of a video image display device. In the modified signal the sensed above-whitelevel noise energy is inverted so as to prevent over-driving of the associated image display device. The noise-adulterated video signal from the video detector is supplied directly to a sync separator and AGC stage without noise inversion so as to avoid the introduction of a spurious DC component capable of falsely altering the video signal level relative to an AGC reference level.

Automatic Terrain Classification From Photography

Abstract: As the acquisition of aerial photographic imagery continues to grow at a rapid rate, automatic data extraction becomes more and more desirable. To this end, an image processing system is being developed to computerize terrain classification. A laser scanner has been used to digitize Apollo 9 imagery of the Salton Sea area. A signature algorithm has been specified allowing the assignment of small image blocks to specific terrain categories. Results of automatic classification and manual photointerpretation are compared. Categories considered are cultivated terrain, uncultivated terrain, cloud covered terrain, and water. Assignment is based on a single black and white transparency in each case. The assignments are displayed as overwritten alphabetic annotation on the original image. Problems are discussed.© (1972) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Heuristic use of image processing technique for theoretical studies of automata

Abstract: Publisher Summary This chapter discusses the heuristic use of image processing technique for theoretical studies of automata. The relationship between the study of pattern recognition and the theoretical study of automata is two folds: (1) Theory of automata will be a base or a background for pattern recognition. (2) Pattern recognition (processing) technique will help the theoretical study of complex systems such as cellular automata. The field of pattern recognition has two distinct goals. One is to construct an effective machine for classifying given images into certain preassigned categories. The other is to know the mechanism of image perception and pattern recognition in a human being or other living organisms. The classification problem is new in the study of cellular automata. The interactive graphic display system with image processing ability seems effective in this study, though definite results have not yet been obtained. The simulation method using unknown variables has been newly devised for visualizing the information transmission. New theoretical results are expected from this kind of man–machine communication, and from two-fold relationship between pattern recognition and theory of automata.

Computer Analysis Of Radiographic Images

Abstract: The significant steps in computer anal-ysis of radiographic images are 1) digitization of the x-ray image; 2) preprocessing of digital images; 3) extraction of significant features; and 4) automatic classification for normal, abnormal, and differential diagnosis. A typical digital image processing facility is described, including the needed interactive type digital displays. Techniques used for preprocessing radio-graphic images are detailed; typically, these are used to ensure a higher degree of success in the later stages of digital processing. Contour tracing and region enumeration algorithms are detailed for use in the com-puter analysis of radiographs. The important descriptive approach to the problem of feature extraction is provided along with illustrative examples. A case study of rheumatic and congenital heart disease is presented for the cardiac shape analysis of PA chest films.© (1972) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A Digital Image Recorder

Abstract: The Princeton University and Hale Observatories have started a joint development effort to design and construct a digital image recorder. This system will use a single-stage intensifier and a silicon-target intensifier television camera tube coupled to a large memory. The output of the memory is fed to a digital computer for data recording and to a video display for real-time monitoring of the integration process. The image on the camera will be read out at intervals

Low-Cost Interactive Image Processing.

Abstract: : The paper describes how to do useful, nontrivial image processing tasks interactively using only a standard alphanumeric CRT terminal, or even a teletype. Only an ordinary time-sharing system is required; there is no need for a dedicated computer or channel, or even for special priority on the system.