Showing papers on "Real image published in 1986"

On Detecting Edges

Abstract: An edge in an image corresponds to a discontinuity in the intensity surface of the underlying scene. It can be approximated by a piecewise straight curve composed of edgels, i.e., short, linear edge-elements, each characterized by a direction and a position. The approach to edgel-detection here, is to fit a series of one-dimensional surfaces to each window (kernel of the operator) and accept the surface-description which is adequate in the least squares sense and has the fewest parameters. (A one-dimensional surface is one which is constant along some direction.) The tanh is an adequate basis for the stepedge and its combinations are adequate for the roofedge and the line-edge. The proposed method of step-edgel detection is robust with respect to noise; for (step-size/?noise) ? 2.5, it has subpixel position localization (?position < ?) and an angular localization better than 10°; further, it is designed to be insensitive to smooth shading. These results are demonstrated by some simple analysis, statistical data, and edgelimages. Also included is a comparison of performance on a real image, with a typical operator (Difference-of-Gaussians). The results indicate that the proposed operator is superior with respect to detection, localization, and resolution.

Method of extracting an image of a moving object

Abstract: A method of extracting an image of a moving object comprises the steps of extracting edge-enhanced input image from an input image taken by an image pick-up element moving in a plane perpendicular to an optical axis, recollecting a background edge-enhanced image from the input edge image, transfer in parallel horizontally and vertically the background edge-enhanced edge image so to correspond to an input edge-enhanced image forwarded successively; extracting an edge image of a moving object by extracting the background edge-enhanced image from the input edge-enhanced image, and renewing the background edge enhanced image based on weighted mean of the background edge enhanced image and the input edge image.

On detecting edges

Abstract: An edge in an image corresponds to a discontinuity in the intensity surface of the underlying scene. It can be approximated by a piecewise straight curve composed of edgels, i.e., short, linear edge-elements, each characterized by a direction and a position. The approach to edgel-detection here, is to fit a series of one-dimensional surfaces to each window (kernel of the operator) and accept the surface-description which is adequate in the least squares sense and has the fewest parameters. (A one-dimensional surface is one which is constant along some direction.) The tanh is an adequate basis for the stepedge and its combinations are adequate for the roofedge and the line-edge. The proposed method of step-edgel detection is robust with respect to noise; for (step-size/?noise) ? 2.5, it has subpixel position localization (?position < ?) and an angular localization better than 10°; further, it is designed to be insensitive to smooth shading. These results are demonstrated by some simple analysis, statistical data, and edgelimages. Also included is a comparison of performance on a real image, with a typical operator (Difference-of-Gaussians). The results indicate that the proposed operator is superior with respect to detection, localization, and resolution.

Catoptric zoom optical device

Abstract: A catoptric zoom optical device comprising a plurality of axially-spaced reflectors disposed in a set for receiving and reflecting energy from an object in the ultraviolet through infrared spectrum to generate a real image of the object and support and drive apparatus for selectively varying the effective focal length of the reflector set to magnify the image and for selectively varying the axial distance between the reflector set and a detector of the image for focusing the image on the detector.

Ring artifact correction for computerized tomography

Abstract: A method for the correction of ring artifacts in images obtained by rotate-rotate computerized tomography (CT) scanners includes the step of reconstructing an original image, which comprises a real image and a ring artifact image. The ring artifact image is determined by edge enhancing the original image and dividing the edge enhanced original image into rings or annuli with the annuli being concentric around the axis of rotation. The average intensity is determined for each concentric annulus. This average value of each annulus is substracted from pixels of the original image belonging to that annulus to provide a ring artifact free image.

Method and an apparatus for determining the refraction

Abstract: The invention relates to a method for determining the refraction of the human eye. The retinal image of an object is imaged via a lens system into an object space and into an image plane which is conjugated with respect to the retina. The spacing of the conjugated plane is analyzed to determine the refraction of the human eye. This analysis is carried out by means of a measuring object which is moved along a plane which is defined by rays of the beam of rays which pass through image points of the retinal image of a target object, such that the beam of rays is divided into two complementing partial beams containing an unevenly divided amount of light energy. The unevenly divided light energy is used to determine the distance of said conjugated plane.

Image output apparatus

Abstract: An image scanning apparatus is provided by (1) a platen on which an original can be placed; (2) a scanning device for scanning the original, which includes a lens for projecting the image of the original on an imaging plane; (3) an image sensor for sensing the image projected on the imaging plane which consists of a plurality of elements arranged linearly along to the imaging plane; (4) a memory device for storing data sensed by the image sensor during a scan by the scanning device; and (5) an assembly for determining the real image area on the original based on the data stored in the memory device. To the above apparatus can be added an output control device for sending digital data of a real image area. A copier according to the present invention which can copy a manuscript, comprises: (1) the above-mentioned image scanning apparatus; (2) is also provided by the above by including an image forming device and (3) a control device for allowing the image forming device to form only the image in the image area. Also, a light controller for an image reader is provided by a standard pattern plate which has a standard pattern of a prescribed density; a light source driven by an electric power source of alternating current, illuminating the standard pattern plate and an original; and can compensate the ac ripples of the image signal.

An Analysis of Error Behavior in the Implementation of 2-D Orthogonal Transformations

Abstract: The paper analyzes the effect of finite-length arithmetic in the calculation of 2-D linear transformations employed in some picture coding algorithms Since the condition of zero-error in general direct and reverse transformations leads to results of little practical importance, an analysis is carried out on the statistical properties of error in 2-D linear transformation with given length of arithmetics Then the important case of discrete cosine transform (DCT) applied to real images is considered in detail The results of the paper allow a circuit designer to determine the representation accuracy of the one- and two-dimensional coefficients required to satisfy a preassigned reconstruction error on the image

Image generation by space sweep

Abstract: A method of using spatial coherence in image generation by raytracing is presented. The idea is to trace a set of rays in parallel. This is carried out by space sweep. Space sweep consists of moving a plane through the object space. The rays intersected by the plane are organized into a dynamic data structure R for range searching. When an object is met by the sweeping plane, those rays intersecting the object are found by a range search with the object in R. Exact complexity bounds are given for this algorithm, as well as details to allow practical application of this approach in image operation.

Optical projection system

Abstract: In an optical projection system in which the mismatching of multiple images and local variation in magnification on an image plane is compensated for, there are provided a compound eye system consisting of plural real image systems which project images of plural portions on an object plane onto the image plane, and deflecting members for deflecting luminous fluxes from the plural portions on the object plane.

Camera optics for producing a composite image from two scenes

Abstract: Lenses (10,11) , e.g. for a camera for a video conferencing system, have divergent optical axes and focus real images via prisms (20,21,22,23) on to a focal plane f. A prism (20) in one path introduces an additional reflection to invert the image while that (22) in the other path causes lateral inversion, so that the two images do not suffer either type of inversion relative to one another. The final reflecting surfaces 211,231 abut in the plane f so that the real images are closely juxtaposed.

Method for reading radiation image information

Abstract: A radiation image information reading method includes scanning a stimulating ray on a radiation image converting panel surface to obtain radiation image information stored on the radiation image converting panel, the scanning step including performing scanning of the stimulating ray while repeating successively irradiation and stopping thereof. In this manner, the noise caused by fluorescent afterflow, stimulation afterglow, stray light from outside of the apparatus or a laser beam, etc., can be removed simply and correctly. A visible image which is correct with good reproducibility corresponding to the real image, and also good in sharpness, can be obtained, whereby diagnosis with high reliability by means of a radiation image is rendered possible. In one embodiment, only image signals detected during periods of irradiation by the stimulating ray are read. In another embodiment, the difference in image signals read during irradiation and during stopping of the stimulating ray is used as the image information.

Edge detection using zero crossings of directional derivatives of a random field model

Abstract: An edge detector using the first and second directional derivatives of a random field model is described. The method consists of representing the pixels in a window by a 2 - D causal autoregressive (AR) model, whose parameters are adaptively estimated using a Kalman filter. Due to the modelling assumption, the directional derivates are functions of AR parameter estimates. An edge is detected if the second derivate in the direction of the estimated gradient is negatively sloped, the first derivatives and a local estimate of sample variance are over some threshold values. We illustrate the performance of the edge detector using real image examples.

Method for the photogrammetrical measurement of an object with at least one solid-state image sensor

Abstract: 1. Method for the photogrammetrical measurement of an object with at least one optoelectrical solid-state image sensor whose image area is smaller than that of the desired whole image, wherein the photogrammetrical imaging system includes the point area of a grid covering the whole image, e.g. a glass plate with suitable point markings distributed in raster fashion, and the image sensor is arranged in the imaging space in such a way that in each case it images at least one unit of the grid, converging the area in the sensor image, wherein the grid points imaged in the digital partial image of the image sensor are adjusted to their nominal position in the scanning grid and the resulting transformation parameters are used to convert the partial image to a unitary whole image system, wherein the image sensor is disposed behind the camera grid disposed in the image plane of the survey camera, so that the camera grid and the photographic object can be projected onto a sensor surface, and wherein the image sensor is displaced from one grid unit to the next for continuous surveying, characterized in that optical separation of object and grid takes place by double exposure, wherein first the grid point are imaged by the image sensor under separate, external lighting without the object information being visible, the resulting first sensor image is stored digitally, and then the object having the same geometrical relationship to the grid is imaged and the resulting second sensor image is also stored digitally.

High-contrast x-ray image detecting apparatus

Abstract: An X-ray image detecting apparatus devised so as to project an X-ray image of an object on a image receiving plane made of two-dimensionally arrayed picture elements with the object irradiated by many thin scanning X-ray beams. The beams, which penetrate the object, scan coincidentally a limited number of the picture elements of which they take a charge respectively, causing the time of scanning the whole area of the image receiving plane to be short. The image signals successively outputted from the picture elements are stored in a memory with only their respective maximum values selected. Thus, the image signals are made free from being adversely affected by the stray X-rays scattered from the inside of the object, and provide a high-contrast X-ray image.

Apparatus for scanning and sampling real images

Abstract: Light from an original is transmitted through two parallel sided glass plates (30, 32) to form a real image on the surface of three area image sensors (24, 26, 28). Selective and incremental tilting or rotation of the two parallel-sided plates provides relative movement between the real image and the area image sensor such that individual area image sensor elements sample a plurality of pixels of the real image.

Method and device for projecting image

Abstract: PURPOSE: To project a delicate and bright image having a high resolution by utilizing a residual image effect, by swinging an optical axis of a light beam passing through a liquid crystal panel, within a residual image forming time range of a vision against a screen. CONSTITUTION: Between a liquid crystal panel 5 and a screen 3, a lens 8' is attached eccentrically to a projecting rotary plate 7' rotating centering around an optical axis 9', and an optical axis displacement mechanism is constituted. At the time of making a light beam from a light source 2 pass through an image which has been formed on the liquid crystal panel 5 by an electronic device 4 by an electronic camera, etc., and projecting it to the screen, the optical axis is swung within a residual image forming time range of a vision by said optical axis displacement mechanism, and the image is varied periodically and projected. As a result, during the first coarse projected image, the next image is projected and joined, therefore,a delicate and bight image having a high resolution can be projected by utilizing a residual image effect. COPYRIGHT: (C)1987,JPO&Japio

Correlation Between Measured Noise And Its Visual Perception.

Abstract: For obvious reasons people in the field claim that measured data do not agree with what they perceive. Scientists reply by saying that their data are "true ". Are they?Since images are made to be looked at, a request for data meaningful for what is perceived, is not foolish. We show that, when noise is characterized by standard density fluctuation figures, a good correlationwith noise perception by the naked eye on a large size radiograph is obtained in applyingmicrodensitometric scanning with a 400 micron aperture. For other viewing conditions the aperture sizehas to be adapted. Introduction Images are meant to transfer information by optical means either to men or to some detecting device. The capability of the images to do so is their real image quality value.A high signal -to -noise ratio (SNR) on the image display (sheet or screen) is in that respect of course a positive item. What really counts however is a high signal -to -noise ratio provided to the observer'sbrain or into the detecting device. A dramatic example between both SNR's provides the well known

Optical sensing of a surface

Abstract: © To locate the upper surface of an object (18) on a substrate (20), a first real image of a Ronchi ruling (parallel bars) (22) is projected by an objective lens (16) and moved into coincidence with the upper surface by vertical movement of a video camera (10) to which the ruling (22) and lens (16) are fixed. The video camera sensor (12) performs line scanning perpendicular to the bars of a second real image of the ruling (22) formed by the lens (16) projecting light reflected up by the upper surface. Accurate coincidence of the first real image with the upper surface provides a camera output signal containing a strong component at a frequency determined by the spatial frequency of the image scanned and the line scan frequency. Measurement of the vertical position of the camera (10) and sensing of several surface provides signals which can be digitally processed to give data on the structure of, for example, a small manufactured article.

Time/Space Recursions For Differential Motion Estimation

Abstract: The alqorithms for the measurement of image motion heavily depend on the uniformity of the motion field Block techniques work only if the whole block undergoes the same motion and point-recursive techniques work only if the motion changes smoothly However, in real images motion changes abruptly at the boundaries of the imaged objects Therefore block techniques are unreliable and pointwise recursion techniques have to be driven by proper tests so that the recursions are stopped and reinitialized where necessary, without causing unnecessary smear The paper analyzes such improvements of the pel recursive motion analysis techniques either for coding, with a progressive scan of the image sequence, or for image interpolation

Improvements Of Directional Decomposition Based Image Coding

Abstract: The directional decomposition has already been introduced as a pertinent tool for image coding. In this paper, this approach is optimized with several steps of refinements in order to improve the compression ratio (up to 120:1) and the quality of the decoded image. After the presentation of the coding strategy, results are shown for various real images.

Forming device for magnified spectral image

Abstract: PURPOSE:To obtain a spectral image of an image which is increased in the quantity of light sufficiently by inserting an acoustooptic element at the object side of the image formation surface of a magnifying optical system. CONSTITUTION:An image of a body 1 which is magnified through the objective lens 2 of a microscope optical system is formed at a position B'-A'. The acoustooptic element 3 is arranged nearby the real image B'-A' at the side of the objective lens. The acoustooptic element 3 has its input and output surfaces formed by polishing TeO2 single crystal. Then, when excitation is performed with the output of a variable frequency oscillator through the acoustooptic transducer, light with wavelength corresponding to the excitation frequency is selected. The selected light forms an image on the photoelectric surface of an image pickup device 4 to obtain a magnified image formed with the homogeneous light from the body 1.

Image sensor apparatus

Abstract: In an image sensor apparatus for reading an image of an object (16) to be read out, light rays emitted from a light source (42) and passing through a slit (38) are converged by a cylindrical lens (46) and are incident on an image transfer optical unit (26). The optical unit (26) has a laminated structure in which a plurality of optical transparent plate segment (44) are bonded by adhesive layers (45). The light rays introduced into respective plate segments (44) are projected to the object (16). The light rays reflected from the object are reintroduced into the respective plate segments (44) and are totally reflected by side surfaces (44-3, 44-4) of the segments (44). The CCD array (30) receives the light rays directly directed from the object (16) and the light rays totally reflected from the side surfaces (44-3, 44-4).

Simultaneous recording method for date or the like of lightning photographic device

Abstract: PURPOSE:To records necessary time on the same film simultaneously with the photography of lightning discharge by lighting a timer device installed separately from a photographic device during photography, projecting its image on the film surface, and photographing it together with a lightning discharge image which is incident simultaneously. CONSTITUTION:When the distance between a closeup lens 8 and the display surface of the timer device is set equal to the focal length of the closeup lens 8, the rays of light passed through the closeup lens 8 are a parallel light beam, so that the display surface of the timer device 4 is at infinite distance when viewed from the photographic lens 2 of a camera 1. The parallel light beam forms an erect real image through a half-mirror 9 and the image is formed on the film surface through the photographic lens 2 of the camera 1 whose photographic distance is set to infinite distance and then recorded simultaneously together with a lightning discharge image formed at the same time. Consequently, the positions of the lightning discharge image and the display surface of the timer device are selected properly to obtain the film where, for example, the lightning discharge image A and timer display image B containing up to year, month, day, hour, minute, and second data are recorded together.

Image pickup device for wall in pipe

Abstract: PURPOSE: To always obtain a precise image by obtaining a wall image in a pipe or in a living body by a solid-state image pickup element which has been provided on a side wall of a tip part of a linear body for an image pickup. CONSTITUTION: A light beam which has been radiated to a wall surface 13 from an optical fiber 1a forms an image on a CCD image pickup element 3 by a condensing lens 4, and an image signal of the wall surface 13, which has been converted photoelectrically is sent successively to an image processor 11 through a signal line 1b and stored. Accordingly, when a linear body 1 for an image pickup rotates, a cylindrical image of 360° of length of the wall surface 13 corresponding to length of the CCD image pickup element 3 is stored in the image processor. The image processor 11 brings an image of one screen portion to a display output to a CRT 12 by a timing of one rotation of a motor 7. Also, a photodetecting surface of the CCD image pickup element 3 confronts the wall surface 13 through the condensing lens 4, therefore, the wall surface 13 is brought to a focus, and a precise electronic image can be obtained in a wide range extending over the peripheral wall surface of a prescribed length. In this way, a position extending from a reference position of the wall surface 13 in the pipe to the affected part can be measured exactly by a precise image. COPYRIGHT: (C)1988,JPO&Japio

A method for extracting three‐dimensional information using cone‐shaped beams of light

Abstract: This paper proposes a method which extracts the three-dimensional information from the single-view image obtained by projecting a texture on the surface to be measured. In the proposed method, the texture is generated by projecting a number of cone-shaped beams of light from point sources on the object surface. Based on the generated texture, the three-dimensional measurement is performed. Since it is difficult to obtain explicit information on the shape of the surface from a single image, more than one light source is used. In other words, two images are obtained by a single camera by varying the location of the point source. By combining the processings of those two images, a simultaneous estimation is made on the normal vector and the three-dimensional coordinate of each point on the image. Compared with the method by two-eye stereo-taxic vision, no processing is needed for determination of correspondence. Compared with the method using slit-light, less time is required for the delta acquisition. Compared with the method utilizing texture, the extraction can be performed without a priori knowledge about textures on the surface. The extraction can be performed only by the local process of the object surface. These are the features of the method. The result of applying the proposed method to the computer-simulated images and real image are presented, together with the discussions of the future problems.

Image pickup device of image composition multiimage fiber

Abstract: PURPOSE:To prevent light of an image part except divided images from entering respective optical fibers and to obtain an image of high quality by providing a light shield body between the 1st optical system which forms a real image of subject and the 2nd optical system which device the real image and form divided images on image fibers. CONSTITUTION:The image pickup device of image composition multi-IF has the 1st optical system which forms the real image 56 of the subject at a specific position and the 2nd optical systems which divided and form the real image of the subject on image fibers (IF) 50, 52, and 54 and are attached to the IFs; and light shield bodies 66 and 68 are provided between the 1st and the 2nd light shield bodies 66 and 68 and nearly in parallel to their center axes in the 2nd optical system, thereby preventing light of an image part except the divided images to be formed on the IFs50, 52, and 54 from entering the IFs50, 52, and 54. Consequently, the respective 2nd optical system receive only luminous flux of corresponding parts of the real images 56 to be formed on incidence end surfaces of the IFs50, 52, and 4 and transmit it to its attached IFs50, 52, and 54, thereby allowing no noise light to enter the IFs50, 52, and 54. Therefore, a composite image of high quality is obtained at projection ends.