Showing papers on "Orientation (computer vision) published in 1978"
01 Jan 1978
TL;DR: It is suggested that an appropriate role of early visual processing is to describe a scene in terms of intrinsic (vertical) characteristics -- such as range, orientation, reflectance, and incident illumination -- of the surface element visible at each point in the image.
Abstract: We suggest that an appropriate role of early visual processing is to describe a scene in terms of intrinsic (vertical) characteristics -- such as range, orientation, reflectance, and incident illumination -- of the surface element visible at each point in the image. Support for this idea comes from three sources: the obvious utility of intrinsic characteristics for higher-level scene analysis; the apparent ability of humans to determine these characteristics, regardless of viewing conditions or familiarity with the scene; and a theoretical argument that such a description is obtainable, by a noncognitive and nonpurposive process, at least, for simple scene domains. The central problem in recovering intrinsic scene characteristics is that the information is confounded in the original light-intensity image: a single intensity value encodes all the characteristics of the corresponding scene point. Recovery depends on exploiting constraints, derived from assumptions about the nature of the scene and the physics of the imaging process.
939 citations
TL;DR: A vision system has been developed which can determine the position and orientation of complex curved objects in gray-level noisy scenes and organizes and reduces the image data from a digitized picture to a compact representation having the appearance of a line drawing.
Abstract: A vision system has been developed which can determine the position and orientation of complex curved objects in gray-level noisy scenes. The system organizes and reduces the image data from a digitized picture to a compact representation having the appearance of a line drawing. This compact image representation can be used for forming a model under favorable viewing conditions or for locating a part under poor viewing conditions by a matching process that uses a previously formed model. Thus, models are formed automatically by having the program view the part under favorable lighting and background conditions. The compact image representation describes the boundaries of the part.
326 citations
Dissertation•
01 Aug 1978
TL;DR: In this article, the distribution of surface orientation and reflectance factor on the surface of an object can be determined from scene radiances observed by a fixed sensor under varying lighting conditions, which have potential application to the automatic inspection of industrial parts, the determination of the attitude of a rigid body in space and the analysis of images returned from planetary explorers.
Abstract: : Distribution of surface orientation and reflectance factor on the surface of an object can be determined from scene radiances observed by a fixed sensor under varying lighting conditions. Such techniques have potential application to the automatic inspection of industrial parts, the determination of the attitude of a rigid body in space and the analysis of images returned from planetary explorers. A comparison is made of this method with techniques based on images obtained from different viewpoints with fixed lighting. (Author)
232 citations
TL;DR: A radar image simulation model, which can be used to aid interpretation of images and information extraction from images, has been developed and implemented on a digital computer and side-by-side comparison with actual radar images of the same site is presented.
Abstract: A radar image simulation model, which can be used to aid interpretation of images and information extraction from images, has been developed and implemented on a digital computer. The model, called the "Point Scattering Model," is a mathematically rigorous treatment of the stochastic process described by the closed system consisting of the radar transmitter and receiver, the ground dielectric properties and geometric orientation of features, and the radar image medium. The vital components of this model are shown to be the operating parameters of the radar, a digital model of the features in the terrain, and a reflectivity model for the features included in the terrain model. Radar images simulated by this model are presented in side-by-side comparison with actual radar images of the same site. The images are shown to substantiate the validity of the radar simulation model.
57 citations
TL;DR: A holographic method has been developed that uses a single wavelength in the recording process to generate a multicolor image under white light reconstruction, each of which is recorded with a specific orientation of the reference beam.
Abstract: A holographic method has been developed that uses a single wavelength in the recording process to generate a multicolor image under white light reconstruction. The final product is a superposition of rainbow holograms, each of which is recorded with a specific orientation of the reference beam. The result is that each scene is encoded with a specific color. The image quality is analyzed and compared with that of other rainbow holograms.
37 citations
TL;DR: Results indicate that achromatic and chromatic information is processed in a similar manner with respect to orientation, and there is substantial, but incomplete, pooling of chromatic and a chromatic orientation information.
Abstract: In most studies of orientation processing, chromatic information and achromatic information have been combined or confounded. The present experiments investigated the relative sizes of tilt aftereffect induced by these two types of information. In these experiments, the tilt aftereffect is the error in adjusting a test contour to vertical, following the scanning of an inspection contour. For inspection and test contours identical except for orientation, the tilt aftereffects varied with inspection contour orientation but not with chromatic or achromatic condition. Smaller tilt aftereffects were obtained when the inspection contour was produced by a hue difference (chromatic information) and the test contour was produced by a luminance difference (achromatic information), or vice versa. These results indicate that achromatic and chromatic information is processed in a similar manner with respect to orientation. Furthermore, there is substantial, but incomplete, pooling of chromatic and achromatic orientation information.
21 citations
Patent•
23 Jan 1978
TL;DR: In this article, a method and apparatus for demonstrating and recording an image of a surface of arbitrary shape and orientation within a body based on a set of tomographic records taken from a radiographic examination of the body is presented.
Abstract: A method and apparatus for demonstrating and recording an image of a surface of arbitrary shape and orientation within a body based on a set of tomographic records taken from a radiographic examination of the body. The tomographic records are overlaid on one another in superimposed relation, and then laterally shifted in concert with one another to bring into virtual focus a continuous succession of laminar images through the depth of the body. As the image of each successive body plane or lamina comes into focus, that part of the image that represents the intersection of the arbitrary surface with the imaged body plane or lamina is selected by masking out the remainder of the focused image. As the focusing progresses through the depth of the body, the entire arbitrary plane is demonstrated, and may be recorded by electronic or photographic means.
8 citations
15 Mar 1978
TL;DR: Digital simulation experiments have been carried out for area correlation of a reference target image with on-board radar acquired images and use of image models based on finite difference approximation of partial differential equations (PDEs) has been studied.
Abstract: : The problem of modeling and processing radar images for tracking applications has been considered. Digital simulation experiments have been carried out for area correlation of a reference target image with on-board radar acquired images. Effects of misregisterations of radar height (scaling) and orientation (rotation) and those of high pass filtering of images have been studied. Use of image models based on finite difference approximation of partial differential equations (PDEs) has also been studied.
4 citations
TL;DR: In this paper, the development of procedures for analytical rectification for oblique aerial photograph by utilizing digital image processing technique was discussed, where the orientation parameters of three dimensional coordinates (Xo, Yo, Zo) and attitude (ω, ψ, κ) were determined from the given coordinates of ground control points.
Abstract: The study deals with the development of procedures for analytical rectification for oblique aerial photograph by utilizing digital image processing technique. Exterior orientation parameters of three dimensional coordinates (Xo, Yo, Zo) and attitude (ω, ψ, κ) were determined from the given coordinates of ground control points.From the results obtained from the study, grid lines indicating the geographic location can be inserted into the oblique aerial photograph, and ortho-photographic image can be generated by image output device, which would be remarkably useful for environmental mapping for coastal zone.
2 citations
01 Mar 1978
TL;DR: Improved qualitative observations are reported and a comparison of the evaluation method discussed here with another edge detection evaluation method is presented.
Abstract: Further work on the evaluation of a particular set of edge detection schemes is described. The orientational bias of these schemes is addressed in particular. Improved qualitative observations are reported and a comparison of the evaluation method discussed here with another edge detection evaluation method is presented.
2 citations
07 Dec 1978
TL;DR: The use of multiple targets as a technique for image evaluation of an optical instrument such as a microscope by means of independently determined curves for probability of correct orientation for a number of observers is described.
Abstract: When performing psychovisual experiments, the averaged results from a multiplicity of trials are a more reliable measure of image quality than the results from a single trial, e.g., such as those obtained from conventional three-bar measurements. This paper describes the use of multiple targets as a technique for image evaluation of an optical instrument such as a microscope. On the basis of experiments conducted at Perkin-Elmer, related to specialized photographic test targets, the Landolt Ring target array was chosen as a basic image evaluation probe signal. The targets, organized in groups having different sizes, modulations, and magnifications, are in circular arrays with the opening in the Landolt Rings randomly placed in four orientations. An observer is asked to identify the orientation of the opening. After the identification, his responses are scored against the known orientations, and the curves of probability of correct orientation are plotted as a function of target size. This function forms a quantitative measure for evaluating the performance of optical instruments. The theoretical analysis portion of this paper is con-cerned with the development of a mathematical model by which optical instrument performance may be ranked. By means of a series of psychovisual experiments, Human Factors Research, Incorporated, has independently determined curves for probability of correct orientation for a number of observers. There is generally good agreement between empirical data and model predictions, approximately 90% for both unaided eye viewing and microscope viewing of test target arrays.
Patent•
30 May 1978
TL;DR: In this article, a developing agent is agitated to obtain the uniform density of toner and eliminate the orientation of an image by reciprocating the sleeve or magnet of at least one of the developing rollers in the axial direction of the roller.
Abstract: PURPOSE:To agitate a developing agent so as to obtain the uniform density of toner, and eliminate the orientation of an image by reciprocating the sleeve or magnet of at least one of plural developing rollers in the axial direction of the roller.
15 Nov 1978
TL;DR: In this paper, a new method of obtaining an x-ray tomographic image of a slice is proposed, where an xray fan beam and detector array are moved in a line across the patient, allowing single scans that are not necessarily transaxial.
Abstract: A new method of obtaining an x-ray tomographic image of a slice is proposed. An x-ray fan beam and detector array are moved in a line across the patient, allowing single scans that are not necessarily transaxial. Projection data is formatted and scaled by micro-processor, and an encoding process is utilized in forming an intermediate record film. This record has a format which somewhat resembles that of synthetic aperture radar, but the coherent light reconstruction of the final image is more complex. All the fundamental limitations of CAT are inherent to the process, except for the slice orientation flexibility. A number of additional limitations are present, some of which are technological. Besides the slice orientation flexibility, there is the potential of achieving better resolution of high contrast objects than current CAT scanners at a much lower total dose than for conventional tomography under comparable contrast conditions.