Showing papers on "Real image published in 1985"

Image Segmentation Techniques

Abstract: There are now a wide variety of image segmentation techniques, some considered general purpose and some designed for specific classes of images. These techniques can be classified as: measurement space guided spatial clustering, single linkage region growing schemes, hybrid linkage region growing schemes, centroid linkage region growing schemes, spatial clustering schemes, and split-and-merge schemes. In this paper, we define each of the major classes of image segmentation techniques and describe several specific examples of each class of algorithm. We illustrate some of the techniques with examples of segmentations performed on real images.

Dynamic Occlusion Analysis in Optical Flow Fields

Abstract: Optical flow can be used to locate dynamic occlusion boundaries in an image sequence. We derive an edge detection algorithm sensitive to changes in flow fields likely to be associated with occlusion. The algorithm is patterned after the Marr-Hildreth zero-crossing detectors currently used to locate boundaries in scalar fields. Zero-crossing detectors are extended to identify changes in direction and/or magnitude in a vector-valued flow field. As a result, the detector works for flow boundaries generated due to the relative motion of two overlapping surfaces, as well as the simpler case of motion parallax due to a sensor moving through an otherwise stationary environment. We then show how the approach can be extended to identify which side of a dynamic occlusion boundary corresponds to the occluding surface. The fundamental principal involved is that at an occlusion boundary, the image of the surface boundary moves with the image of the occluding surface. Such information is important in interpreting dynamic scenes. Results are demonstrated on optical flow fields automatically computed from real image sequences.

Computing Dense Displacement Fields With Confidence Measures In Scenes Containing Occlusion

Abstract: Matching successive frames of a dynamic image sequence using area correlation has been studied for many years by researchers in machine vision. Most of these efforts have gone into improving the speed and the accuracy of correlation matching algorithms. Yet, the displacement fields produced by these algorithms are often incorrect in homogeneous areas of the image and in areas which are visible in one frame, but are occluded in the succeeding frames. Further, these displacement fields are often incorrect even at non-occluded areas that border occlusion boundaries. In this paper, we present a confidence measure which indicates the reliability of each displacement vector computed by a specific hierarchical correlation matching algorithm. We also provide an improved hierarchical matching algorithm which performs particularly well near occlusion boundaries. We demonstrate these with experiments performed on real image sequences taken in our robotics labaratory. A more detailed version of this work appears in (Anan84).

Magnetic resonance imaging with phase encoded chemical shift correction

Abstract: A shimming magnetic field control (22) causes shimming magnetic fields for improving uniformity of a main magnetic field generated by main magnets (10). A resonance excitation control (32) selectively applies a resonance excitation pulse (34) and inversion pulse (36) for inverting the spin magnetization of water and lipid dipoles. A phase sensitive detector (30) selectively receives resonance signal components which are transformed by a transform algorithm (70) into a real image (72) and an imaginary image (74). The inversion pulse (36) is shifted by a time such that the water and lipid spin magnetizations are out of phase by a predetermined amount. With a 90° phase difference, the real image represents water and the imaginary represents lipid. A phase image (80) is derived from a reference image pair (76, 78). A phase unwrap circuit (82) removes ambiguities attributable to the spin magnetizations becoming dephased by multiples of 2π to create a phase map (84). A shim adjustment circuit (94) measures uniformity of the phase map and causes the shim field control circuit (22) to adjust the shimming magnetic fields to optimize the measured uniformity. The phase map is inversely transformed (100) to generate a field map (102) indicative of geometric distortion. A geometric distortion correction circuit (106) selectively interpolates values in the real and imaginary images in accordance with the field map to correct the image for geometric distortion.

Stereo image display using a concave mirror and two contiguous reflecting mirrors

Abstract: Stereo views of a scene are reflected by plano mirrors onto a concave mirror. The plano mirrors are positioned to cause the reflected light from the concave mirror to converge on and cross the optical axis. The concave mirror focuses real images in planar registration in front of the concave mirror and on the optical axis. When viewed from beyond the real images an observer sees a separate stereo view in each eye which combine to provide a 3-D picture.

Three-dimensional vision system

Abstract: The present invention consists in a three-dimensional vision system comprising a three-dimensional vision sensor which projects slit-like light on an object to-be-handled and which reads out a resulting slit image, an image input portion which controls the slit-like light to be lit up and put out and also controls the read-out of the slit image and which performs extraction processing of differential signals as to image signals read out, and an image processor which performs required controls concerning said image input portion and which processes image data of said image input portion; an image with the projected slit-like light and an image without it being sequentially sampled on an identical scanning line of the read-out image so as to obtain the differential image between them, thereby to extract a light segmentation line based on the projected slit-like light.

Method and system for effecting a transformation of a video image

Abstract: A method and system for effecting a transformation of video image on a video screen applicable to a system for producing a special visual effect on, e.g. a television screen, in which a two-dimensional address plane (IM) is defined within a memory area, input video image is stored within the memory area, a cylinder shaped virtual image (CYL) is placed on the address plane, a part of the address plane (iM2) is wound on the cylinder shaped image (CYL), and when the cylinder shaped image (CYL) is displaced along a predetermined direction on the address plane (IM) with a radius (r) of a circle invertical section thereof being varied with time, the address plane (IM) can be viewed as if it were turned over. If the input address data within the memory area is read out on the basis of output address data indicating the above-described displacement of the address plane (IM), the output video image on the video screen can be viewed therethrough as if the video image were being turned over.

Ring field projection system

Abstract: The present invention is directed to Optical Lithographic Systems which are particularly adapted, among many other possible uses, for use in effecting exposure of photoresist-coated semiconductor wafers, having a ring field projection system which includes at least one concave and one convex mirror arranged around an optical axis in face-to-face relationship with their centers of curvature being nearly concentric and falling on the axis, the convex mirror being smaller than and having a smaller radius of curvature than the concave mirror, an object location and a conjugate real image location, said convex mirror being positioned to reflect to the concave mirror light from the object location initially reflected from the concave mirror whereby light from the object location will be reflected at least twice at said concave mirror and at least once at the convex mirror before being focused at the image location, elements for limiting the image field to an annular zone centered about the optical axis, a first thick, flat parallel plate mounted in the light path between the object and image locations adjacent the object location, a second thick, flat parallel plate nearly identical to the first plate mounted in the light path between the object and image locations adjacent the image location, a first pair of symmetrically disposed nearly concentric meniscus elements mounted in the light path between the object and image locations at a spaced distance from the plates, respectively, a second pair of symmetrically disposed meniscus elements mounted in the light path between the object and image locations adjacent the first pair of meniscus elements, and the plates and elements being constructed and arranged so that the meniscus elements reduce spherical aberration of the principal rays in the system and introduce chromatic aberrations which are substantially cancelled by the thick, flat parallel plates.

Holography of space-time events

Abstract: An investigation is made of the process of holographic recording and a reconstruction of spatial and temporal characteristics of an optical field. It is shown theoretically and experimentally that this can be achieved by recording spectral amplitude–phase holograms in spectrally selective light-sensitive materials capable of storing harmonic components of the reference and object waves. A report is given of experiments on low-temperature solid solutions of large organic molecules in which stable narrow dips in the impurity absorption spectrum can be "burnt out" by photochemical reactions. The causality principle operating via the phase part of a hologram results in selection of one of the images: either a virtual image with a direct time dependence or a real image with a reversed time dependence. An experimental check of the properties of spacetime holograms yielded a fairly high (for practical applications) diffraction efficiency of ~50%.

On Stereo Viewing of SAR Images

Abstract: The interpretability of side-looking radar images can be significantly enhanced by the use of overlapping image strips viewed stereoscopically. Although the subject has been studied for many years, the lack of systematically acquired data has meant that the optimum sensor geometry for good stereo viewing and mapping accuracy is still undetermined. This paper attempts to evaluate stereo viewability using available real images and describes on-going work utilizing digital elevation maps and computer image simulation.

Radiation image inspection apparatus

Abstract: A radiation image inspection apparatus for inspecting articles. The inspection apparatus includes a radiation source which generates and directs radiation, preferably x-rays, toward and around the article. The radiation penetrates and passes around the article and strikes a screen having a coating formed of a rare earth element. The coating exhibits fluorescence when struck by incident radiation and becomes illuminated, generating a first light image of the article. The first light image passes through a plurality of lenses which maintain the intensity of the light image before striking a camera having a front camera screen. The camera by means of an internal sweep beam scans the camera screen and generates an electrical output signal corresponding to the image on the camera screen. A controller controls the operation of the camera and radiation source in either of two modes. In the first mode of operation the radiation source is energized to continually generate radiation and the camera output is blanked for a pre-determined amount of time after the inspection sequence begins to enable radiation energy to build up on the screen thereby maximizing the intensity of the visible light image generated on the screen. At the end of the pre-determined time interval, the camera is activated to generate a signal corresponding to the image on the camera screen. In the second mode of energization, the radiation source and the camera are pulsed for a short time period, with the radiation source being energized at a high intensity level.

Image fiber with a mechanism for rotating a field of view

Abstract: In an inspection device having a light guide, an image fiber and a mirror for reflecting light from the light guide to an object and for reflecting an image of the object to the image fiber, the mirror is rotatable about an axis coincident with the optical axis at the end of the image fiber.

A nonrecursive filter for edge preserving image restoration

Abstract: This paper is concerned with developing a nonrecursive filter for edge preserving image restoration. The original image is represented by a Gaussian Markov random field (GMRF) model. This assumption forces the restoration filter to be a function of GMRF model parameters. Since the original image is rarely available, methods are developed for the estimation of model parameters from the degraded image. The degradation is due to signal-independent additive white noise. The resulting filter blurs the edges in the image. By using the notion of masking function, an edge preserving filter (EPF) is developed. The EPF is a linear weighted combination of a stationary Wiener filter and an identity filter where the weights are determined using the spatially varying masking function. The usefulness of the algorithm is illustrated using a real image.

Television game machine

Abstract: The game machine has two display units, and one image-synthesizing half-mirror. One display unit is adapted to display images of a background and an object which are not controlled directly by a player, and the other an image including an image of an object which can be controlled to a predetermined extent by a player. The half-mirror is adapted to reflect the image formed on one display unit, and produce a mirror image thereof at the front side or rear side of an image on the other display unit. The player sees the image appearing on the latter display unit as well as the mirror image of the image on the former display unit. Since the above image and mirror image are spaced at a suitable distance, a three-dimensional view can be obtained. One display unit or the half-mirror is, in some cases, supported so that it can be moved in a suitable direction.

Magnification converting copying machine with non-image part destaticizing device

Abstract: PURPOSE:To prevent the image of an original and a pattern image from being superposed on each other, and to form other pattern image than the original image so as to be easily visible on a form by using a blank lamp, by providing a range for forming the pattern image on other part than the image range of an original on the form. CONSTITUTION:The blank lamp can be used as a means for forming other pattern image than the image of the original. For instance, in case of forming a pattern image, in case of copying the image of the original 81 of an A4 size to the form 82 of the same A4 size, a copying magnification of 0.93 is set. As a result, the image of the original is copied in an image range 82a on the form 82, and also a pattern image forming range 82b of (y)=10.5mm width in the direction vertical to the form carrying direction is provided as a margin. This pattern image forming range 82b corresponds to the position of a high density LED array 2a, the high density LED array 2a is controlled in accordance with the pattern image, and the image is formed in the pattern image forming range 82b.

Enhancing real-time perception of quantum limited images from a doubly intensified SIT camera system

Abstract: By a combination of three separate enhancing procedures, the visual perception of quantum limited images from a sensitive low-light camera system has been improved with significantly less image lag than is obtained using digital averaging alone. The camera system employed consists of a dual microchannel plate image intensifier optically coupled to a silicon-intensified target vidicon. With this camera system a major portion of the background noise can be removed by passing the video signal through an adjustable video slice circuit which excludes low level signals and represents signals above the slice threshold with a uniform white value. In addition, real image information can be integrated on the vidicon target by reducing the vidicon beam current to induce image lag of up to 2 s duration. Finally, the remaining noise which is characterized by lack of lag can be easily removed by moderate digital averaging. The enhancement obtained by these techniques is continuously variable allowing the user to select an enhancement level appropriate for the image under study.

Position measuring device

Abstract: PURPOSE:To improve efficiency and precision by calculating the variation distance between photodetection positions on reference surfaces and actual measurement surfaces of an inclination measurement part and a displacement measuring part, and calculating the inclination and displacement extents of the measurement surfaces to the reference surfaces. CONSTITUTION:Laser light 10 is reflected by a measurement surface 22 to obtain regularly reflected laser light 13 and diffuse reflected laser light 14. the regularly reflected laser light 13 is photodetected at a position SA on an image sensor 12 through a translucent mirror 11. Then, the measurement surface 22 moves in parallel by a displacement extent (d) and also slants by an angle theta as shown by a measurement surface 22', the light is relfected at a position P1. In this case, the regularly reflected laser light 13 is changed in direction at a position H1 of the translucent mirror 11 and photodetected at a position SA1 on the image sensor 12. The diffuse reflected laser light 14, on the other hand, is so converged that a real image of a beam spot position P is formed as a real image of a position SP on an image sensor 16 through an optical system 15. Then, the beam spot position P1 is image-formed at a position SP1 on the image sensor 16.

Apparatus for reading an arbitrarily oriented image

Abstract: An image reading apparatus for reading an image of an original and converting it into an electrical signal, and particularly for reading the image by primary-scanning and secondary-scanning the image by a one-dimensional image sensor. This apparatus has one or two one-dimensional image sensors and is constructed such that the image reading state (for reading by the image sensors) differs when the image is placed in a vertically facing posture at an illuminating position compared to when the image is placed in a horizontally facing posture at the illuminating position, and can properly read the image and reproduce the same when the image is placed in any of these postures.

Picture splitting system high resolution image pickup device

Abstract: PURPOSE:To double resolution by splitting light to two directions by a reflecting mirror etc. and make the light form images on two solid-state image pickup elements using separate lenses. CONSTITUTION:Light passed through a lens 1 forms a real image on the image forming plane F of the lens 1. A reflecting mirror or a prism 2 is placed to bring an end of its reflecting face at a position + or -delta from the position of the plane F, and the real image picture is splitted to two directions shown by arrow marks A, B. Images of light splitted to two directions are formed again on CCD image pickup elements 5, 6 by lenses 3, 4. A picture 7 is the picture image of which is formed on the element 5, and a picture 8 is the picture image of which is formed on the element 6. delta' indicates superposition of the picture 7 and picture 8, and lightness of the superposed part becomes the same lightness with other parts by composing the picture 7 and picture 8. Thus, a continuous picture having doubled resolution can be obtained.

Defect detecting device

Abstract: PURPOSE:To enable accuracy and rapid detection of a surface defects, by memorizing an image signal of a work and operating a difference of the image signal obtained by slight change of an optical distance and the memorized one. CONSTITUTION:A ray of light is projected from a downward illuminating source 4 onto a video-disc on a support and its reflected light is formed on a real image forming plane 22 of a ITV camera 23 and its image is displayed on a monitor 26. When a flow is found by driving a work support 2 and scanning is performed all over the disc 1, then the scanning is stopped. A light source 17 is turned out, a ray of light from a laser 10 is projected onto an inspection plane 19 of the work and a mirror 15a through collimator lens 11 and beam splitter, and its interference image is formed on the splane 22. Its image signal is stored in a memory of an image processing unit 25 and a difference of the image signal issued when the surface mirror 15 is given with inching displacement by a micro- feed mechanism and the memorized signal is operated in an image analyzing unit 6 for tabe representation 26 and thus, a surface defect can be detected with high accuracy and rapidity.

Measurement of dimension

Abstract: PURPOSE:To achieve a shorter measuring time and a higher accuracy by performing the scanning with a slit made up of a transparent portion and a non- transparent portion of a liquid crystal according to an electrical signal being switched over to the scanning direction CONSTITUTION:A sample 1 is expanded with an object lens 3 by desired magnifications while a gap 2 is expanded to the size as shown by 4 to form an image on a plane 5 of expanded real image A slit 7 moves through a liquid crystal 6 fixed to match the expanded real image plane 5 in the direction of the arrow A by an electric control Assuming the slit 7 comprising a non-transparent portion 7a and a transparent portion 7b, a part 8 of the real image only passes through the liquid crystal 6 An photoelectron transducer 9 is made up of an photoelectronic plane 10 adapted to release photoelectron in a photon unit receiving light from the slit 7 and an electrode 12 for taking in photoelectrons 11 released and a signal 13 of the photoelectron transducer is obtained from the electrode 12

Single channel masking camera & projector

Abstract: An optical imaging system for producing and applying image masks consisting of an original object holder, an image forming optical system, recording means for the image formed, processing means for the recorded image, means for maintaining the recorded image in precise register with the original object. The recorded image is projected back on the original in a modified form by means of adding and controlling optical flare in the imaging system to control image contract and by well known means control image color and sharpness. This modified projected image in register with the original objects acts as a mask for image enhancement. The resulting enhanced image can then be recorded by photographic film or paper and other ray recording devices.

Image forming system having uniform illumination flux for liquid crystal image means

Abstract: A light source is disposed and spaced apart from a display surface and the light from the light source is changed into the light rays having a substantially uniform distribution of luminous flux density by a light control device such as a mirror having a specially designed configuration before the light reaches the display surface. An image generation device such as a transmission type liquid crystal image generation device is inserted in the path of the light rays having a substantially uniform distribution of luminous flux density, and the such light rays transmitted through the image generation device forms an image on the display surface with uniform intensity of illumination. In order to form a color image, three optical systems as above corresponding to the three red, green and blue primary colors are provided and the lights from the three primary color light sources are transmitted with a time difference to an image generation device. In synchronism with this transmission, the three primary color image signals are sequentially transmitted to the image generation device, whereby a color image is formed by the color sequence process. When the above optical systems are provided for respective primary colors and three primary color image signals are synchronously applied to three image generation devices, a color image is formed by the additive process. The above-described color image formation systems can attain a high degree of convergence.

Device for double-image superimposing and displaying

Abstract: PURPOSE: To easily obtain a superimposed image by forming and displaying an object image as the 1st image by a normal optical method, detecting only distribution information on invisible observation elements which can not be image-formed by a detecting device, and visualizing and displaying it as the 2nd image by the 2nd image display device and superimposing this 2nd image upon the 1st image. CONSTITUTION: An image forming device 2 and a sound collector 3 are installed facing a sound source body 1 and the 1st and the 2nd images are put in focus. The focusing of the 1st image by the image forming device 2 is carried out by operating a lens barrel 12 and the focusing of the 2nd image, on the other hand, is attained by installing a microphone array 4 constituting the detecting device at the sound image formation position of reflected sound from the sound collector 3. Namely, the microphone array 4 is moved to and away from the reflecting surface of the sound collector 3 and positioned 4 where the quantity of light from a light emitting diode array 21 is maximum. Then, the 1st and the 2nd images are focused associatively and then one image is focused automatically by focusing only the other image. COPYRIGHT: (C)1986,JPO&Japio

Parameter estimation and classification of machine parts based on specular or mirror-like image data (robot vision, shape from shading, surface classification)

Abstract: This thesis presents least squares estimation techniques for 3-D object location and orientation using the specular or mirror-like reflections seen from objects in a single image. The techniques are derived by calculating the exact equations specifying where specular reflections should be seen in images as a function of object type, location and orientation, and camera and light source location and orientation. Then the true parameters of the objects in the scene are estimated through suitable approximations. Equations are derived to approximate the conditions found in an average manufacturing environment as accurately as possible. The approach presented here may be used for estimating machine part location and orientation as an independent, self-contained scheme or in conjunction with other scene analysis operators. A specific type of concurrent operator may be one of many. A few examples of such operators are relaxation type surface region discriminators, texture segmenters and classifiers employing Markov Random Fields, constrained surface fitting for surface parameter estimation, or constrained line and curve fitting for estimation of object location and orientation. The estimates produced by the statistical operators of this thesis are fairly accurate, which is shown with some experiments with real image data; therefore, they are useful either as a first-stage approximator for object orientation and location or as a verification procedure for other approaches.

Circumferential scanning type photographing device

Abstract: PURPOSE:To obtain a high-resolution image even through an optical system having large image curvature by using no image near an optical axis although an optical system which is symmetrical about the optical axis, and using only an image on a circumference of symmetry about the optical axis. CONSTITUTION:Photodetecting elements 14-14 are arrayed closely along the circumference of symmetry about the optical axis 13 on the image-formation surface 12 of an optical system 11 which forms a real image of a subject and symmetrical about the optical axis, e.g. Maksutov optical system. Outputs of those photodetecting elements are converted by a shift register 16 from parallel to serial and image processing is performed. Elements within a sector or semicircle range between a left and a right angle alpha about a track direction are used for the image processing. Consequently, problem points due to the image curvature of the optical system of optical-axis symmetry are eliminate completely. In other words, photography with a wide view angle and high resolution which is conventionally impossible is enabled although the optical system having large image curvature is used.

Three dimensional shape estimation from two dimensional images

Abstract: In two dimensional images of three dimensional reflecting surfaces, both the shape of the surface and the positions of sources of illumination determine relative values of image intensity. Segmentation of objects and estimation of surface shapes from 2D images are important research areas in scene analysis and computer vision. Many analyses of shape determination assume Lambertian surfaces which have no shadows, diffuse illumination, or specular reflections. While these results provide a good basis for shape from shading analysis, the nonlinear effects specifically omitted from consideration will, in most images of real objects, cause more error in shape estimation than additive white Gaussian noise processes. This paper considers segmentation of objects and estimation of surface shape in the presence of these nonlinear effects and demonstrates results both with well-behaved synthetically generated images and with real images acquired under somewhat controlled conditions.

A hybrid image coding technique using a noncausal stochastic model

Abstract: This paper presents a technique for data compression of a grey-level still image. The image is considered to be a two-dimensional homogeneous random field that satisfies a noncausal stochastic difference equation driven by a white noise field. The difference equation model is isotropic and characterized by the two parameters of the variance and the correlation length of an image only. This model is simple and can easily fit various types of images. Based on the above model, we develop a hybrid algorithm which combines a one-dimensional cosine transformation and a one-dimensional prediction. The algorithm is applied to a real image to check its validity.