Showing papers on "Orientation (computer vision) published in 1968"

Contrast of a Stacking Fault on X‐Ray Topographs

Abstract: The contrast of the image of a stacking fault on a section topograph is discussed in detail. The intensity distribution of the X-rays reflected by a crystal containing a stacking fault is the sum of three terms: the first one is due to interferences between waves which have suffered no interbranch scattering, the third term is a cross term due to interferences between waves of both types. The latter is shown to be the predominant term when the crystal is absorbing. This is confirmed by experiment. The derivation has been done using Kato's spherical wave approach and the stationary phase method. The expressions are given for an absorbing crystal and an asymmetrical orientation of the reflecting planes and the stacking fault with respect to the crystal faces. There is good agreement between the calculated intensity distribution and that observed in the image of a stacking fault.

Advanced methods for the calibration of metric cameras

Abstract: : A new analytical approach to the problem of the accurate calibration of metric cameras is developed and specific applications are reported. The method permits an indefinitely large number of frames from a given camera to be reduced simultaneously, yet efficiently, to produce common parameters of the inner cone for all frames, as well as independent elements of exterior orientation for each frame. Because control points may be exercised repeatedly in a common reduction, very large sets of well distributed residuals can be generated from a relatively small set of control points (in principle, a complete and accurate calibration could be performed from as few as three control points). From such large sets of residuals empirical functions can be derived to account for persistent, unmodelled systematic error. In addition, it becomes feasible to establish the variation in the accuracies of the radial and tangential components of plate coordinates throughout the format and thus to establish appropriate empirical weighting functions for subsequent applications. The method is of universal applicability and encompasses calibrations from aerial photographs, calibrations from stellar photographs, and calibrations from multicollimator photographs. Applied to stellar calibrations, the method leads to improved accuracies and convenience by completely doing away with conventional requirements for precise timing of the shutter and for stability of the camera throughout successive exposures. Applied to multicollimator calibrations, the method has far reaching implications concerning both the use of existing multicollimators and the design of future multicollimators.

Rotation translation independent feature extraction means

Abstract: A means of electrically extracting optical information from an optically recognizable pattern regardless of the orientation of the pattern within the field of view and comparing the information extracted against electrical criteria so as to classify the pattern wherein the pattern image is projected onto an image slicer which utilizes fiber optics to divide the image into a plurality of slices. Electrical processing is used to assign a number to each slice which is proportional to the light flux incident upon the slice and to square the assigned number. All the squared numbers are added to generate a voltage which is memorized. The image is then rotated with respect to the slicer and subsequent voltages are generated and memorized. The memorized voltages are then compared to an electrical template to determine the classification of the pattern and its orientation within the field of view.

Optical apparatus and methods for viewing or displaying images

Abstract: THIS APPLICATION DEPICTS, INTER ALIA, METHODS AND APPARATUS FOR SELECTIVELY RETRIEVING ONE OR MORE OF A PLURALITY OF IMAGES STORES IN SUPERPOSITION UPON A RECORD IN RESPECTIVE MULTIPLICATION WITH SPATIALLY PERIODIC MODULATION OF UNIQUE AZIMUTHAL ORIENTATION. WAYS ARE SHOWN FOR VARYING THE REALTIVE INTENSITY OF THE RETRIEVED IMAGES. DISCLOSED EMBODIMENTS OF THE INVENTION ARE ADAPTED FOR VIEWING OR DISPLAYING IN NATURAL OR SELECTIVELY DISORTED COLOR A SCENE RECORDED ON BLACK AND WHITE FILM AS THREE SUPERIMPOSED COLOR SEPARATION IMAGES RESPECTIVELY MODULATING A SPATIAL CARRIER OF DISTINCT ANGULAR ORIENTATION. YET ANOTHER EMBODIMENT IS ADAPTED FOR VIEWING OR DISPLAYING A SELECTED ONE OR MORE OF A LARGE NUMBER OF DIFFERENT SCENE IMAGES WHICH HAVE BEEN RECORDED IN SUPERPOSITION ON A COMMON RECORDING MEDIUM IN RESPECTIVE MULTIPLICATION WITH AN ANGULARLY UNIQUE SPATIAL CARRIER.

The Derivation of a Coefficient of Degree of Preferred Orientation from Contoured Fabric Diagrams

Abstract: Significance tests and concepts of degree of preferred orientation applied to three-dimensional orientation data have been discussed many times (Stauffer, 1966; Voll, 1960; Flinn, 1958; Drescher-Kaden, 1954). These tests are based on some form of statistical correlation or on departures from some ideally random model. These tests tend to be too sensitive for comparison of diagrams which have an obvious preferred orientation, and vectorial summation methods are limited to simple preferred orientation patterns. For convenience, a “coefficient of degree of preferred orientation” needs to be a numerical value which can be simply and quickly derived from a contoured stereographic projection. This note demonstrates that an empirical property of contoured stereographic projections of natural preferred orientation data can be used to derive such a coefficient.