Showing papers on "Feature (computer vision) published in 1972"

Techniques ror Change Detection

Abstract: The problem of change detection presents itself for imaging systems that view the same scene repeatedly. Current research programs based on the processing of side-looking radar imagery show that spatial alignment of the various parts of the image must be highly accurate if noise in the difference picture is to be reduced to acceptably low levels. Typically, the spatial alignment accuracy must be better than one-fourth of the diameter of the smallest resolvable feature in the imagery, and this often requires several hundred degrees of freedom in the performance of the map warp for images that are of the order of 107picture cells (pixels) in size. Gray scale rectification of conjugate sampling points is less difficult, requiring typically only 10 to 20 percent as many degrees of freedom. Point by point adjustment for differences in mean transparency and contrast is employed. Recently developed equipment provides a continuous pipeline processing capability. With this equipment, each picture element of the second image is transformed with four degrees of freedom (two spatial and two gray scale). The digital correlator is capable of processing 4×105six-bit picture elements per second when used in conjunction with a CDC 1700 computer.

A Nonlinear Feature Extraction Algorithm Using Distance Transformation

Abstract: Feature extraction has been recognized as a useful technique for pattern recognition. Feature extraction is accomplished by constructing a mapping from the measurement space to a feature space. Often, the mapping is chosen from an arbitrarily specified parametric family by optimizing the parameters with respect to a separability criterion.

Classification and Evolution of Ornithopod Dinosaurs

Abstract: ALTHOUGH I agree with the main themes of Thulborn on the origin of ornithischian dinosaurs1–3, I disagree4–6 with the current classification of the family Hypsilophodontidae7–8, in respect to premaxillary teeth as a diagnostic feature, cheeks, cheek teeth and locomotor capabilities.

The use of parent-child interaction patterns in therapy for young stutterers.

Abstract: Nine school-age stutterers were seen in an experimental therapy program. The basic feature of the program was that parent-child interaction patterns were used in the planning of therapy. Such behav...

Psychology, the hybrid science

Abstract: This text has feature not found anywhere else, we want to give you an over view of the major changes we've made and point out the methods for teaching and learning newly built into the text

Feature selection in image analysis

Abstract: Circuit arrangements are described by which a signal from a socalled light pen is employed to gate the output from a threshold detector set to detect amplitude excursions of a video signal which exceed a reference voltage. In this way the detected signal pulses corresponding to a feature towards which the light pen is pointed, alone, are released and measurements may be made thereon to provide information about the selected feature. A preferred form of light pen is described in which switch means is provided by which it is possible to select which of a plurality of stores is to be supplied with the information obtained about any feature. In this way operator controlled pattern recognition may be performed.

Recent advances in automatic image analysis using a television system.

Abstract: SUMMARY Image analysis, in the context of this paper, comprises the extraction of quantitative geometric and densitometric data from images produced by optical and electron microscopes or any other imaging system. Typical measurements include area percentages, intersect counts, feature counts, size distributions and integrated density determinations. Much of the stereological work is still performed by manual methods, but technological progress in recent years has considerably promoted the use of automatic image analysing devices. This paper describes recent developments in scanner performance and the correction of shading errors which allow reliable densitometric measurement. In addition, the previous geometric capabilities have been extended to include feature selection by pattern recognition criteria.

Reflections on the History of the Concept of Time

Abstract: The central feature of our current mode of thought about the physical universe and human society is the idea of time as linear advancement without cyclical repetition. We tend to regard this idea as intuitively obvious and a necessity of thought, but a general survey of the historical evidence reveals that this is not the case.

Functional Types of Student Evaluation.

Abstract: Although recent emphasis in the evaluation literature has concentrated upon curriculum evaluation, student evaluation remains a pervasive and crucial feature of all teaching. This article defines f...

Cough monitoring apparatus

Abstract: An apparatus that receives ambient sounds and recognizes the occurrence of coughs to the exclusion of other sounds. Means are provided for translating the received sounds into a plurality of spectral component signals. A feature signal generating means is provided for sensing the presence of properties of the spectral component signals that are characteristic of coughs and for generating a feature signal for each property found to be present. An occurrence decision means, responsive to the feature signals, generates an occurrence indication upon receiving a predetermined combination of feature signals. In a preferred embodiment of the invention, the occurrence decision means is programmable to the cough of a particular individual.

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.

Erase feature for data recording device

Abstract: This invention relates to a method of recording data and more specifically to apparatus for recording data wherein a control unit is utilized to regulate a data recording device and the data recording device is provided with means for accomplishing independently certain of the writing tasks in a manner to free the controller for other tasks.

Search Time as a Function of Context Letter Frequency

Abstract: Neisser (1967) posits the operation of purely feature analytic processes in the scanning of context letters in search lists. This contention was tested by varying the relative frequency of occurrence in English of the context letters in alphanumeric search lists, while holding their feature content constant. It was hypothesized that faster search time on lists of high-frequency context letters would indicate letter-level processing. Equality of search time would indicate the purely feature-level processing required by Neisser's theory.Context letters were segregated into high- and low-frequency sets and their features defined and held constant according to two feature analyses. This yielded a 2 × 2 design with 22 subjects per condition. Attention was given to the control of feature frequency, size of the context-letter set, and approximation of English at the level of bigram, trigram, and word. Results supported a letter level or template model of processing but were shown also to be explainable in terms ...

A comparison of four feature systems using data from three psychophysical methods.

Abstract: Four feature systems (Miller-Nicely, Singh-Black, Wickelgren, and Chomsky-Halle) were compared under three different perceptual tasks involving the ability of subjects to auditorily discriminate pa...

Redundant inertial measurement system with improved failure-detection capability

Abstract: A redundant inertial measuring system includes at least two gimballed platforms each stabilized by at least three gyros. Means are provided for detecting excessive drift in at least one of the gyros and for eliminating the defective unit or units from control of the system. A particular feature of the invention is that all gimballed platforms are mechanically identical, and therefore interchangeable.

Free-form discriminatory verbal responses to polygon patterns.

Abstract: Summasy.-Free-form sentences, produced by Ss in response to eight-sided polygons, were tabulated in Associative, Orientative, Area, Jaggedness, Part, and "Blank categories. Intercorrelations with feature measures of polygons and latency and primacy (ease of learning) from previous experiments indicated several significant relationships, e.g., forms with a high frequency of Area and Jaggedness responses had consistently lower discrimination latency.

The evolution of controllable domains

Abstract: Calculations of the domains T-controllable to the origin for a certain class of differential systems are presented. These are shown to have re-entrant sections in the case of the Duffing oscillator, and an explanation of the feature is given

Detection of Buried Geological Ore-Bodies by Reconstructed Wavefronts

Abstract: A new seismic method based on concepts of reconstructed wavefronts is described. It employs a mono-frequency source of seismic energy and records the interference pattern between the scattered waves from the geological feature of interest buried at a certain depth and the direct waves travelling along the surface. The interfering direct waves that do not contribute to the characteristic signatures of the geological ore-body are removed by spatial filtering before reconstruction.

Feature association in image analysis

Abstract: Methods and apparatus are described by which detected signal pulses arising from features in a field can be associated to thereby generate so-called agglomerates of features, in dependence on the relative spacing of the features in the field. In this way it is possible to link up the detected signal pulse information relating to small features arranged approximately in straight lines. The invention generates capture zones from each feature one extending in the line scan direction and the other generally perpendicular thereto. The invention envisages the combination therewith of an associated parameter computer whereby information may be obtained relative to a parameter of each detected feature. The information from features within an agglomerate may be suppressed or collated and released as a single information signal relating to the agglomerate. Thus where a count pulse is generated for each feature these may be inhibited from all features within an agglomerate and the latter counted as a single feature. Alternatively where a signal proportional to the area of each feature is generated by the associated parameter computer, these may be combined for features within an agglomerate and a total area signal released for the agglomerate proportional to the total of the individual areas of the features within the agglomerate.