Abstract: A multi-image single passive sensor depth recovery system is disclosed to determine the depth of an object in a scene, and includes a passive imaging sensor which images radiation from an object at a sensor plane. A lens having a multiplicity of facets located on its surface nearest the object is placed in optical communication with the sensor so that each facet directs radiation from the object to sensor plane to form a corresponding image of the object thereon. The size and shape of each of the facets are selected to position each image on the sensor plane at a predetermined position thereon.

Abstract: A lead shape measurement apparatus includes a first perspective imaging device for photographing external leads to be measured, from an oblique direction; a second perspective imaging device for photograping external leads to be measured, from an oblique direction different from that of the first perspective imaging device and so as to include a same photographic field of vision as the first perspective device; a first measurement point determination element for determining a center point of two intersecting virtual straight lines which intersect two ridges of the external leads to be measured in an image plane by photography of the first perspective imaging device; a second measurement point determination element for setting epipolar line in the image plane by the second perspective imaging device on the basis of sight lines when a measurement sampling point of the first perspective imaging device is photographed, and for determining a center point of two intersecting virtual straight lines which intersect t

Abstract: Digitized stereo image pairs are analyzed by first aggregating the images to produce several levels of lower resolution images, bandpass filtering each of the images by applying a Laplacian filter to edge enhance the features, matching the features of low resolution images while generating a disparity image which contains elevation information, repeating the feature matching at successively higher resolutions and creating progressively improving disparity images, and extracting the elevation data from the final disparity image. The feature matching procedure uses an estimate of feature disparity to help locate a feature in one image which corresponds to a feature in another image and is applied iteratively at each level of resolution. Dilation of disparity data from matched points to neighboring unmatched areas produces a comprehensive disparity image which aids in more efficient feature location on the next pass.

Abstract: A method for determining a surface topology of a workpiece preferably comprising a general symmetric asphere. The method includes the steps of coupling a projectile to a surface of a workpiece, and imparting a trajectory to the projectile with respect to the surface; sensing the trajectory of the projectile with respect to the workpiece surface, for assessing a locus of positional points over time of the projectile, the locus being a measure of the surface topology of the workpiece; and computing from the locus of positional points over time, the surface topology of the workpiece.

Abstract: A method of making stereophotographic documentation and photogrammetric of impressions or of models of jaws, in which the impression or the model of a jaw is placed on a reference object, which in its turn is placed on a bottom plate in a photo device. The photo device includes camera mounted in a frame at a distance from the bottom plate and a light source for illuminating the impression or model on the reference object. A picture of the impression or the model of a jaw is taken by means of the camera, when the camera has position at a predetermined given reference angle distance from the vertical line. A second picture is taken of the impression or the model of a jaw after the camera has been moved to a corresponding position on the other side of the vertical line. The two pictures are placed on a tray which is intended is cooperate with a stereoscope in such a way that the two pictures can be seen three-dimensionally in the stereoscope.

Abstract: A cavity monitoring system includes a supporting system adapted to be installed in an access leading to a mined stope, or any other cavity, a mast mounted on the supporting system and adapted to extend into the cavity, and a laser rangefinder mounted at the end of the mast. The laser rangefinder is capable of being rotated around the axis of the mast and directed at the wall of the cavity at angles varying from 0 to 145 degrees from the axis of the mast so as to scan concentric circles on the wall of the cavity permitting a series of distance measurements to be taken to obtain the shape and volume of the cavity.

Abstract: The camera includes two functionally equivalent line and field scanners, one for issuing a light pulse that will be returned by an object point, and identified by a particular line/field scanning position in both scanners; the second scanner being attuned to recognize the returned light in one scanning raster point only for purposes of correlation. The field scan is realized through a deflecting mirror or in a columnal array the line scans are either solid state or fiber optics.

Abstract: A mechanism for determining parallax between first and second digital images employs an iterative image pattern search and correlation process, which is able to rapidly determine the parallax for each pixel that is common to the images captured by a stereo image pair. By the initial use of a dispersed sub-array of reference point pixels distributed throughout a first image array, a similarly dispersed sub-array of tie points, to be used as starting points for subsequent, more densely populated search and correlation steps, can be rapidly obtained for the second image array. The derived parallax values may then be subjected to an interpolation function to sub-pixel accuracies. Once the parallax between the first and second image arrays has been derived, elevations can be computed using a conventional parallax-dependent mechanism.

Abstract: The close range Photogrammetric Laser System ("PLS") is an all digital system designed to measure three dimensional ("3-D") surfaces at relatively close ranges. The PLS comprises two modified stereo cameras with associated analog video and digital recording capability. Using synchronized laser illumination and X and Y cylindrical lens arrangements in each stereo camera, all laser illuminated points can be focused onto a linear detector array whose intensities are used to calculate X and Y position of a 3-D target in the image plane of each camera. Photogrammetric techniques are then used to calculate an X, Y and Z position from the X and Y positions measured in the two stereo cameras. An alternate embodiment eliminates the intermediate recording step in favor of a direct recording in the memory of a data processing system for subsequent manipulation.

Abstract: A pulsed laser illumination based one camera ranging and imaging system which requires only a single axis optical aperture and is therefore suited to use on aircraft and other space and configuration limited apparatus is disclosed. The invention uses intensity coded partial images of the distant target in a single camera with the partial images being obtained by a distance segregating optical modulation arrangement which separates pixel portions according to their arrival time and thereby the distance of travel from the target. The described system uses pixel by pixel processing of the segregated images as accomplished in an image array processor, for example.

Abstract: A pulsed laser illumination based two camera ranging and imaging system which requires only a single axis optical aperture and is therefore suited to use on aircraft and other space and configuration limited apparatus is disclosed. The invention uses intensity coded partial images of the distant target with the partial images being obtained by a distance segregating optical modulation arrangement which separates pixel portions according to their arrival time and thereby their distance of travel from the target. The described system uses pixel by pixel processing of the segregated images as accomplished in an image array processor or general purpose computer, for example.

Abstract: A method and apparatus are described for image matching, particularly for increasing match information in scene matching navigation systems. The invention correlates a sequence of sensed images with a reference map and stores the resultant correlation surfaces. The correlation surfaces are then added so that match point correlations combine coherently by superposing the individual correlation surfaces using short term accurate navigation data. As a result, a composite correlation surface is formed in which the values at the peak (or antipeak) position add up and the effective match area is greatly increased. Both peaks and antipeaks are then detected to determine a match point and provide a navigation position update.

Abstract: Range discontinuities (44) in an imaged scene are located with superior accuracy by using a pair of stereoscopically related images (10, 12) of the scene to sense edges in the scene, and to determine the range of correlatable image pixels; segmenting the scene into regions (36) of similar intensity; assigning to each region (36) a range based upon the range of any correlatable pixels in it; and locating the boundary (44) between adjacent regions of substantially dissimilar range.

Abstract: A sensor assembly to be carried on an aircraft or spacecraft which will travel along an arbitrary flight path, for providing an image of terrain over which the craft travels. The assembly includes a main linear sensor array and a plurality of auxiliary sensor arrays oriented parallel to, and at respectively different distances from, the main array. By comparing the image signals produced by the main sensor array with those produced by each auxiliary array, information relating to variations in velocity of the craft carrying the assembly can be obtained. The signals from each auxiliary array will provide information relating to a respectively different frequency range.

Abstract: In the determination of the position and geometry of workpiece surfaces, especially weld grooves in automatic arc welding, the workpiece surface or a section thereof, is imaged from two different observation points onto two image pickups. This is so that mutually shifted images of the workpiece surface are reproduced on the two image pickups. This is as well as from the position and the spacing of the defined points of the workpiece surface on the two image pickups. The position of these defined points within the spatial coordinate system of the measuring device is calculated in order to then determine from the position of all calculated points the geometry of the workpiece surface as well as the position of the latter with respect to the observation system.

Abstract: A system for determining the attitude of an airborne or spaceborne platform such as a terrain image sensor or an energy beam pointer includes a digital image correlator for comparing successive overlapping, instantaneous images of the terrain which are recorded by a second, two-dimensional image sensor whose image plane is oriented parallel to that of the platform or terrain image sensor. The second sensor generates an instantaneous master image and a subsequent slave image which at least partially overlaps the master image in terms of the terrain which is viewed. The master and slave images are approximately registered and a correlation is performed. A plurality of points on the slave image are correlated with the corresponding terrain points on the master image. The relative orientation of the slave image with respect to the master image characterizes the attitude change of the platform. The technique also reveals changes in altitude and velocity of the platform when mean altitude and velocity are known.

Abstract: An endoscope is presented which enables one to carry out measurement of an unevenness existing on an object by the use of laser beams, without being affected by white light for observation. White light is irradiated on the object only during the time when measurement of the unevenness is not being carried out, and the image information obtained by the use of the white light is displayed continuously while being stored in a memory.

Abstract: An optical location system having a beam projection device (11, 51, 12, 13) to illuminate the field of view, and a detector array (29) to detect reflected light (21) from the field of view. The projected beam (13) is incrementably progressed across the field of view and for each increment the reflected points of light (61) detected by the detector (29) are recorded to build a map of the field of view, which is stored as a sparse array having as its first coordinate the angle of projection (A) of the illuminating beam (13) and as its second coordinate the azimuth angle (B) of the reflected ray detected by the detector. The value stored in each element of the array is the angle of the incidence (C) of the horizontal component of the detected ray with the detector.

Abstract: The invention relates to the stereophotogrammetry. A coordinate grid is made in the form of a support (1) carrying a stereophotograph of an image of one or more groups of straight lines (4) converging at a main point (3) and closed lines interconnecting them. The latter, according to the invention, are essentially circles (5) the centers of which are offset relatively the point (3) in one and the same radial direction by an amount of the parallax corresponding to the camera-to-object distance which is represented by the circle circumscribed from this center. The lines (4) and the circles (5) are made in the form of dash lines. The lengths of and the intervals between the dash lines, and the radii of the circles (5) determine the value of a grid division. The dash lines may be made colored and in each group of the lines the dashes have an individual color. The coordinate grid is mainly designed for use in stereoscopes for measuring stereophotographs of an object image.

Abstract: A three-dimensional shape of an object is recognized by developing enveloping surfaces of the object by a cone-silhouetting method, wherein the object is picked up by a binocular three-dimensional vision method by making use of geometrical restraint conditions derived by the cone-silhouetting method. The binocular parallax is increased to thereby ensure the recognition of the three-dimensional shape with improved accuracy. Local concave portions which can not be recognized by the cone-silhouetting method by itself are recognized with higher accuracy.

Abstract: A range imaging system, and a method for calibrating such a system are based on the principles of projective geometry. The system comprises four subsystems: (1) a laser and a cylindrical lens or vibrating mirror for producing a planar beam of light; (2) an electronic camera equipped with a lens and an appropriate interference filter; (3) an electronic circuit for height (depth) measurements and video image generation; and (4) a scanning mechanism for moving the object with respect to the light beam and the camera so as to scan an area of the object surface. The system is calibrated by determining the position in the electronic image of the object surface at three different heights. The range image is generated from these three known heights from either a previously determined look-up table, or from a calculation based on the invariance of the cross-ratio, a well known ratio from projective geometry.

Abstract: Methods and apparatus for determining the curvature of a surface by use of multiple discrete triangulation sensors are described. Robustness in the face of an extreme manufacturing environment is achieved by placing a triangulation light source and a detector at a remote, environmentally controlled location. Light is relayed from the remote source to each sensor head by a single mode optical fiber, which then projects a spot onto the surface under consideration. An image of the spot is formed in each sensor head, and is relayed back to the remote detector by a coherent bundle of fibers. Range to the surface at each sensor head is inferred by the position of each image as relayed by the coherent bundles, while curvature of the surface is determined by comparing ranges as measured at each sensor head. The optics contained in each sensor head are adapted to work well with specular, diffuse, opaque or transparent surfaces.

Abstract: A hand-held device enables repeatable computerized imaging and analysis of a surface feature by combining the functions of alignment, illumination and imaging in a unitary device. The probe consists of a physical standoff having one end contacting the surface surrounding the area to be imaged. The imaging device, in the form of a lens and a charge coupled device (CCD), is mounted on the standoff at a distance from the surface area fixed by the standoff. The imaging device has its focal plane at or near the surface area to be imaged as controlled by the physical dimensions of the physical standoff. The imaging device is constructed having a depth of focus corresponding to the depth of the feature of interest on the surface area to be imaged. The illumination, in the form of a ring light disposed about the imaging device, focuses light at the focal plane of the imaging device.

Abstract: An optical radar system for coherent ranging and velocimetry. Modulation of a laser diode by light backscattered from a target is used to determine distance and velocity of a target. An array of laser diodes are used to determine the velocity and topography of a target. Three laser diodes are used to determine speed and orientation of a rotating disk.

Abstract: A mensuration apparatus for converting film images and paper drawings into digital photogrammetric arrays to be computer processed, displayed, mensurated and analyzed. This mensuration apparatus includes a table on which a translatable camera and a reseau assembly are mounted. The reseau assembly includes an object mounting plate for mounting an object such as a photograph, map, or the like, and a grid mark system for superimposing grid marks on the object. The translatable camera includes a solid state camera having a two-dimensional array of light sensor elements mounted over the reseau assembly in a translatable mounting apparatus. Said translation camera can be moved to any desired position over the reseau assembly, as well as toward and away from the reseau assembly, forming three coordinate systems, which are correlated together for precise mensuration of an object image digitized by the solid state camera.

Abstract: A method and apparatus for measuring the total volume of a group of elongated objects, such as a load of logs on a transport vehicle, is described. Each end of the load is imaged on photographic film with two cameras whose geometric lens characteristics, separation distance, and focal lengths are known. The imaging can be done before, during or after the unloading of the logs from the vehicle. A specially modified stereographic projector mounting all four film images and using digital output devices is then used to transfer the information, permanently stored on the images, to a digital computer. The computer is used to transform the dimensions of the three dimensional stereo image produced by the stereographic projector to the real world dimensions in which the photographic images were originally produced. The computer, in turn, calculates the length of each log, the cross sectional area of the wood (excluding bark) at each end of each log, the volume of wood on the load, etc.

Abstract: This invention relates to an optical system for determining the curvature or the modification of curvature of an object on a zone of small dimensions, wherein it comprises: a light source; first optics adapted to form a parallel light beam from the beam emitted by said source; a semireflecting element disposed on the path of said parallel beam; second focussing optics receiving the parallel beam reflected by said element and being capable of moving parallel to the direction of propagation of said light beam, so that their image focus merges with the center of curvature or the surface of said object; third focussing optics receiving the beam reflected by the object, and means for detecting the image formed by said system. The invention is more particularly applicable in keratometry.

Abstract: A novel method for determination of 3-D structure in biplane angiography, including determining the distance of a perpendicular line from the focal spots of respective x-ray sources to respective image planes and defining the origin of each biplane image as the point of intersection with the perpendicular line thereto, obtaining two biplane digital images at arbitrary orientations with respect to an object, identifying at least 8 points in both images which correspond to respective points in the object, determining the image coordinates of the 8 or more identified object points in the respective biplane images, constructing a set of linear equations in 8 unknowns based on the image coordinates of the object points and based on the known focal spot to image plane distances for the two biplane images; solving the linear equations to yield the 8 unknowns, which represent the fundamental geometric parameters of the biplane imaging system; using the fundamental parameters to calculate the 3-dimensional positions o

Abstract: Apparatus and method for obtaining three-dimensional information about an object, includes a first optical system, a projection device, a second optical system, and an image sensor. A plurality of pattern beams are radiated onto the object through the first optical system. Optical images formed by the pattern beams on the object are received by the image sensor through the second optical system to detect the positions of the received optical images. The distances from the detected positions of the optical images to a plurality of positions on the object are measured, thereby obtaining three-dimensional information about the object.

Abstract: This invention relates to a method for generating images by using a ray-tracing method. The method for generating images according to the invention registers only a cell containing the surface of an object among cells that are obtained by dividing the region containing the object to be displayed. The calculation of intersection points is performed only for rectangular parallelepipeds in which the surface exists. Thus it is possible to reduce the time required for displaying the object.

Abstract: A coordinates measuring apparatus comprising a detecting unit constituted by an optical system for obtaining an image of an object and a detecting system having a plurality of arrayed detecting elements disposed in such a manner that respective detecting signals are superposed at the position of said image, a control unit for taking out data from each of said arrayed detecting elements, and a storage unit for storing the data of each array taken out from said control unit.

Abstract: Three-dimensional measurement of a surface of an object under inspection is performed by projecting a light pattern upon the surface, having a periodic, smoothly varying light intensity in the X direction and having a non-changeable intensity in the Y direction in the manner of a grid, and thereafter electronically producing a pair of stereo images of the surface so illuminated by a pair of CCD arrays; measuring the parallax phase offsets between correlated corresponding homologous points in the stereo images, and converting the resulting parallax data to an array of Z-depth data, indicative of the shape of the surface of the object.

Abstract: A shape measuring apparatus is disclosed.

Abstract: A system for determining the attitude of an airborne platform such as a terrain image sensor includes a digital image correlator for comparing successive overlapping, instantaneous images of the terrain which are recorded by a second, two-dimensional image sensor whose image plane is oriented parallel to that of the terrain image sensor. The second sensor generates an instantaneous master image and a subsequent slave image which at least partially overlaps the master image in terms of the terrain which is viewed. The master and slave images are approximately registered and a correlation is performed. A plurality of points on the slave image are correlated with the corresponding terrain points on the master image. The correlation is performed by selecting a plurality of spatially distributed patches of pixel arrays which are mathematically superimposed on and are moved about the slave image to determine the locations where the maximum of gray scale correlation occurs.

Abstract: A coordinates measuring method in which the image information of the same point are derived as first, second and third information when viewed from at least three different directions, a first corresponding point is determined by deriving the correlation between the first and second information, and a second corresponding point is determined by deriving the correlation between the second and third information, and mismatching is decided when the first and second coordinates are not substantially coincident with each other.

Abstract: Method for the binocular stereoscopic moving image representation of image scenes sensed with relative movement between a single monocular imaging sensor and a scene area, in particular aerial image scenes. The method uses left and right frames for said representation which are sensed at different times during said relative movement. For the continuous stereoscopic representation of almost the whole image the frames are each combined from parts of at least three consecutive sensed images of an image sequence overlapping in pairs. The parts of the at least three images are rectified under consideration of the geometric parameters of the actually sensed images such that the image scale for said parts is equal. The method is also applicable if sensed images are transmitted from said imaging sensor with a reduced frame rate and by imaging-adapted interpolation and/or extrapolation on the basis of two transmitted images.

Abstract: Method of determining stereoscopic geometry of an object through photometric stereoscopic measurement with high accuracy. Three or more images of the object picked up in a same fixed direction by varying the state of light sources are derived. Relationships among the images are corrected so that an evaluation function determined by making use of redundancy of the images assumes a minimum value, to thereby prepare a reflectance map to be used in determining orientations of surface elements of the object. Through integration of the orientations, the surface shape of the object is determined. The method is applicable to the image processing in a scanning electron microscope.

Abstract: A cartographic apparatus for determination of the elevations of features and heights of objects from stereoscopic images of complementing input records includes a parallax bar and movable reticles for generating a floating mark over points of interest in the records. The apparatus also includes a microprocessor to compute compensation factors based on values determined during initial set up and means responsive to those factors to compensate automatically for y parallax and for errors in x parallax difference as the floating mark is moved and to compute automatically object heights and feature elevations.

Abstract: A stereophotogrammetric surveying and evaluation method is presented. A camera is carried over the terrain of interest, the camera having three sensor lines arranged transversely or obliquely to the line of flight. From the resulting three overlapping line image strips both elevational terrain data and camera orientation data are statistically obtained.

Abstract: Several properties are assigned to the regions of an image having light and shade and obtained by photographing a surface of an object. Several properties are also assigned to the regions of the picture, which are extracted on the basis of the first proper-assigning operation, and the boundary lines therebetween. The angles of inclination of these regions and the condition of the unevenness of the regions of the surface which are on these boundary lines are estimated by utilizing the relation between the above-mentioned properties and the direction of a light source. Thus, the relative elevation of the surface of the object is determined. The above-mentioned properties are determined with respect to images of the same object from different directions, and the properties thus determined of these images are compared to determine the corresponding points, which are utilized to determine the quantitative elevation of the surface.

Abstract: A pair of photographs of the same object taken from different positions and fixed to a single carrying plate the position of which can be adjusted in a first plane. Three measuring devices are associated with the carrying plate for determining the coordinates of the plate to indicate the distance and angle of the plate relative to a fixed reference system. Binocular optical means includes two measuring marks respectively having lines of sight intersecting said two photographs. The lines of sight are parallel to one another and lie in a plane disposed perpendicular to the first plane. One of the marks can be moved relative to the other so that the lines of sight may intersect identical points on the two photographs. A fourth measuring device is provided for measuring the distance between said lines of sight. The outputs from the four measuring devices are fed into a computer for deriving three dimensional quantitative information about the object.

Abstract: A three-dimensional range camera, which produces a range map of the distances from a reference to each of M.times.N points in a scene, is modified to generate registered luminance and range images. The same sensor detects range and luminance variations. A planar pattern projector generates sequential presentations of time/space coded light rays which are projected onto the object. A linear array camera images the points of light on the object surface, and a processor analyzes one-dimensional scan signals to determine range. To detect luminance there is an additional presentation, either constant illumination or no artificial illumination, and the other scan signal yields luminance along the same strip of the scene.

Abstract: A non-contact sensor system measures distance from a reference plane to many remote points on the surface of an object. The set of points at which range is measured lie along a straight line (N points) or are distributed over a rectangular plane (M.times.N points). The system is comprised of a pattern generator to produce a 1.times.N array of time/space coded light rays, optionally a means such as a rotating mirror to sweep the coded light rays orthogonally by steps, a linear array camera to image subsets of the light rays incident on the object surface, and a high speed range processor to determine depth by analyzing one-dimensional scan signals. The range camera output is a one-dimensional profile or a two-dimensional area range map, typically for inspection and robotic vision applications.

Abstract: A system for recognizing a three-dimensional object includes a plurality of image pickup apparatus, e.g. TV cameras, by which images of the object are picked up from at least three directions. Feature points are extracted from each of at least three images obtained. Two sets of feature points on epipolarly lines are formed which lines are formed on at least two of the images by a feature point on another image. A set of feature points is selected which satisfy a restricting condition determined by the relationship of the image picking-up direction.

Abstract: Two images to be registered are divided into a plurality of image portions. A standard point for the registration is extracted for each of the image portions divided. Coordinate transformations between two images for the registration are conducted for each image portion by using the standard point extracted. The coordinate values transformed between the image portions are smoothed in the case that they discretely change so that they may be smoothly connected.

Abstract: A method for the stereophotogrammetric survey of a large-dimension object is provided in which the object and a chain having two reference markers thereon spaced apart at a known distance are photographed from a height of about 30 m with two synchronized metric photographic cameras spaced apart by about 6 m. Depth measurements (Z axis) are made on a stereoscopic model reproduced by a stereoplotter at eight sets of points grouped in the eight conventional perimetral locations of photogrammetric orientation at the crests and troughs of the ripples or undulations of the water or ground, respectively. The mean of the depth measurements is calculated to determine the mean horizontal plane and the model is correctly orientated with respect to the horizontal plane by suitable rotation.

Abstract: Disclosed in an optical distance measuring apparatus using an observation lens and at least one reflector. Thanks to the use of reflectors the whole size of the apparatus reduced at least one half of a conventional distance measuring apparatus, still assuring the same exactness as the conventional apparatus in measuring a distance.

Abstract: Methods are provided for reducing the number of projected patterns required to make two- or three-dimensional surface measurements on a sub-class of surfaces comprising relatively smooth surfaces. By including apriori knowledge about the surface to be measured, pattern ambiguities can be resolved by processing rather than by additional projected patterns.

Abstract: Methods are provided for reducing the number of projected patterns required to make two- or three-dimensional surface measurements on a sub-class of surfaces comprising relatively smooth surfaces. By including apriori knowledge about the surface to be measured, pattern ambiguities can be resolved by processing rather than by additional projected patterns.

Abstract: A method of obtaining data for mathematical characterization of a wave surface by transmitting a beam toward the surface so that the beam is reflected from an element of the surface in a direction determined by the instantaneous, two dimensional slope of the element. The reflected beam impinges on a screen as a spot whose time varying coordinates correspond to the time varying slope of the element. These coordinates are captured by scanning the screen with a raster scan which controls counters identifying the spot position. The instantaneous distance is measured by a capacitance probe to relate the captured coordinates to the corresponding angles of reflection by appropriate trigonometric relations.