Showing papers on "Zoom published in 1983"

Interactive image query system using progressive transmission

Abstract: There is a growing need for people to browse through files of images such as satellite or medical photos, to determine which ones warrant further examination. Users located at some distance from the image archive often must use slow transmission links such as telephone lines. If an image is scanned out line-by-line, top-to-bottom, the user must often wait too long to determine whether the image is of any use. Using the Progressive Transmission Method, however, images are encoded so that during transmission the entire display shows a rough version of the image in 'fat pixels'. If the user wishes to see more detail, additional data is sent and used to refine these pixels, until the exact original image is seen. We report here on extensions of this method to the rich color imagery found in remote-sensing applications. A significant advance is the elimination of unworkably large look-up tables by using a single simple algorithm for performing the required encoding and decoding operations. The method is conceptualized in a 'transmission cone' context which assists a user in interacting with the system. The user can roam over large images, zoom to various levels of resolution, and cause specified subregions of interest in the image to fill in to full resolution, at a tremendous saving in time.

Solid-state color TV camera image size control

Abstract: The apparent size of the image produced by a clocked solid-state television imager is controlled by the read clock rate. In a camera using such an imager the clock rate is adjusted to provide an effect similar to zoom. Where a plurality of imagers are used in a color camera, differential control of the clock rate as between the imagers allows compensation for lens chromatic aberration thereby providing for correction of misregistration. In the case where the optical system includes a variable focal length such as a zoom lens, the zoom control is coupled to the size clock control for compensating for the differences in optical power for different colors. The size adjustment may result in a second-order centering error. The centering error is reduced by a scheme for changing the time at which the read clock is gated to the imager in dependence upon the clock rate.

Zoom indicating apparatus for video camera or the like

Abstract: A zoom indicating apparatus for a video zoom camera that provides a viewfinder raster display of a scene within the field of view of the camera superimposes upon the raster display a zoom frame that indicates the portion of the scene that would be within the field of view of the camera at its maximum zoom setting. The apparatus converts a zoom setting signal from the camera to a signal corresponding to the magnification at that zoom setting, employs the magnification signal for generating zoom frame signals which define the size and location of the zoom frame on the display, and combines the zoom frame signals with the video signal from the camera to form a composite video signal that is applied to the display. The apparatus automatically adjusts the position of the zoom frame on the display so as to compensate for misalignment between the optical axis of the camera lens and the center of the scanned image on the camera sensor tubes.

Method and means for real time image zoom display in an ultrasonic scanning system

Abstract: Real time image zoom is obtained by sampling electrical signals corresponding to reflected ultrasonic waves at a sampling frequency whereby display data is obtained only in an area of interest. The sampling is delayed to eliminate signals from areas not of interest. Ultrasonic pulse repetition rate is selected so that internal resolution in the area of interest is optimized.

Video recorder with automatic variation of zoom ratio

Abstract: PURPOSE:To obtain consecutively the clear pictures of different zoom ratios, by stopping a lens instantaneously every time the zoom ratio reaches each set value of a series prescribed zoom ratios and starting immediately the drive of the lens after image pickup to shift the zoom ratio to the next set value. CONSTITUTION:A comparator 3 compares the set value read out of a read command device 11 and the zoom ratio detected by a zoom ratio detector 2 and transmits the working command signal for a period during which the detected zoom ratio reaches the set value. A lens driver 8 shifts the lens while the working command signal is applied from the comparator 3. Then the shutter is released for image pickup by means of a shutter driver 9 when the drive of the lens is stopped. The device 11 gives a read command for the next set value when the shutter closes a prescribed time later and in response to the driver 9.

Zoom lens having a large zoom ratio

Abstract: A zoom lens having at least four components of which the 1st counting from the object side is of positive power, the 2nd is of negative power and the 3rd and 4th are of positive or negative power, wherein the 2nd component is made fixed, and the 1st component and at least one of those that follow the 2nd component are made movable for zooming, whereby the bulk and size of the lens system is minimized, while still permitting good correction of aberrations.

An analytical technique for stable aberration correction in zoom systems

Abstract: It is assumed that the powers and movements of the components in the zoom system are known. One position of the zoom is designated the reference position, and the primary (third order) aberrations, including the spherical aberration and longitudinal chromatic aberrations of the pupil, of each component are used as independent variables. For the reference position and for a series of other zoom positions, paraxial marginal and pupil (principal) rays are traced. Initially these rays are traced assuming each component to consist of thin lenses in contact: subsequently they are traced through designed components. Using the data from these rays, the primary aberrations of each component in any of the other zoom positions are expressed as linear combinations of their values in the reference position. Special cases can arise, such as when the pupil in some other zoom position coincides with the object position in the reference position. These special cases lead to the need for four separate sets of coefficients, and a simple initial test indicates which set is to be used. In cases where a given component acts nearly as a field lens, the primary aberrations of the pupil for the reference position are used as independent variables in place of those of the image. The total primary aberrations of the whole system in the selected zoom positions are set equal to zero, or are given target values, and the resulting set of equations is solved by the method of damped least squares, using weightings for the overall aberration residuals and damping factors for the independent variables. For the initial, thin-lens, design there are only three independent variables (the spherical aberration, coma, and longitudinal chromatic aberration). The values of these needed for stable correction of the primary aberrations are determined, and the different components are then designed. The resulting thick-lens components will usually show greater variations of the aberrations on zooming than those predicted by the thin-lens solution. The formulae employed, which are perfectly general, are then used to obtain changes in the values of the primary aberrations of each component in the reference position (possibly with target-values for the overall primary aberrations in each zoom position if ray-tracing has revealed the higher order aberrations present) prior to re-design of the components. The technique is also useful in studying ways of improving an existing design in an economical way; for example, by imposing the condition that only one component may be subjected to re-design.

Wide angle zoom objective

Abstract: A wide angle zoom objective has three lens units of which the first counting from front is of negative power, the second is of positive power and the third is of negative power. At least one lens surface in the first unit has an aspheric surface, and the units are arranged to move differentially during zooming.

POPEYE: A Gray-Level Vision System for Robotics Applications.

Abstract: : A gray-level image processing system has been constructed to provide capability for inspection, object orientation, object classification,and interactive control tasks in an inexpensive, stand-alone system with moderate processing speed. The POPEYE system offers a range of functions including algorithms for preprocessing, feature extraction, image modeling, focusing, automatic pan, tilt, and zoom, interactive communication with other devices, and convenient user interaction. The host processor is a Motorola 68000 processor with Multibus communication between principal modules, an image data bus for acquisition and storage and a pipeline bus for image preprocessing and programmable transform operations. The software structure provides hierarchical control over multiple i/o devices, file management of system storage, an image management package and a vector package. Performance of the system is evaluated using convolution filters, adaptive modeling, histogram modification, and connectivity analysis. Cellular logic operations, piecewise gradient segmentation, automatic focusing, and adaptive spatial filtering examples are described in detail. The system is being applied to a number of practical industrial applications. (Author)

Compact Infrared Continuous Zoom Telescope

Abstract: In the field of infrared optics (8-12 microns) there is an increasing requirement for continuous zoom telescopes operating with scanner systems. To date, zoom telescopes have for some applications been precluded due to excessive length. An exercise was undertaken to explore the possibility of length reduction. The study resulted in the design of a compact, high performance IR zoom telescope. This design and its development will be described including achromatisation, athermalisation and tolerancing aspects.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Changing method of angle of view of zoom lens

Abstract: PURPOSE:To attain the changing method of the angle of view of a zoom lens which is small-sized and is superior in operability, by inserting an attachment lens to the movement space on the optical axis where a moving lens group which is moved on the optical axis for zooming is moved. CONSTITUTION:An attachment lens F consisting of, for example, a negative lens 18 and a positive lens 19 is inserted to the movement space of the moving lens group in a zoom lens consisting of a variator 13, a compensator 14, etc. In this case, the zoom lens is preliminarily set in the zoom position in the wide angle end, and the attachment lens F is inserted to the movement space of a moving lens group E, and the zoom position in the wide angle end is changed to the wide angle side furthermore. This attachment lens is constituted with two lens groups having negative and positive refractive powers at least to change the angle of view without degrading the optical capacity essential to the zoom lens.

Methods for evaluating the number of relevant documents in a collection

Abstract: Two essentially practical methods which do not rely on the uncertainties of the statistical approach are proposed. The method of limiting recall has been used with a document collection of over one million items; it requires test searches to be carried out independently by several groups. The use of a very new and powerful retrieval aid named ZOOM is also proposed as a form of super-search for each test question, the results of which can be assumed to be close to the total number of relevant documents. Used together, these two methods would provide cross-verification.

Automatic focusing zoom lens device

Abstract: PURPOSE:To prevent an image surface moving speed from varying with focal length, by providing a driving controller which varies the driving speed of a focusing lens driving means by the output of a zooming information detecting means. CONSTITUTION:A zoom lens 1 consists of a focusing lens 4, variable power lens group 5, compensating lens group 6, and fixed lens group 7. Incident light L is observed through the mirror 8, etc., in a camera body 2. Light passed through a semitransparent part 8' reaches a photoelectric element 13 for focus detection. The motor 18 for the zoom lens is driven through a contact 16 by a signal from a focus detecting circuit 14 to move the lens group 4 and a barrel 20. When a zoom operation ring 22 is rotated, a brush 28 slides on a resistor 29 and zoom ratio information is detected from its resistance value to vary the rotating speed of the motor 18 by a lens driving control circuit 17 on the basis of the zoom ratio information.

Optical correcting type zoom lens

Abstract: PURPOSE:To increase the degree of freedom for deciding the power, by constituting so that a focus shift is corrected completely by non-linearly moving one of the lens components, or a relay part placed behind the zoom part. CONSTITUTION:The variable magnification part is formed by 4 lens componentsI-IV, the first componentIand the third component III, and the second component II and the fourth component IV are connected, respectively, and they are variably magnified so that each group executes each different linear motion. An optical correcting system zoom lens of this invention is formed by structurally increasing one cam to a conventional well-known optical correcting system zoom lens whose variable magnification part consists of 4 components, and as for the cam to be increased, a linear cam can be used, therefore, the working can be executed easily. In this way, by non-linearly moving one of the lens components, or a relay part placed behind the zoom part, it is possible to obtain a mechanically correcting system zoom lens which has completely corrected a focus shift.

Determination of the damping characteristics of structures by transient testing using zoom-fft

Abstract: For many years , experimental determination of t h e dynamic c h a r a c t e r i s t i c s of s t ruct u r e s has been based on s teady-state d i s c r e t e frequency methods, i n which t h e n a t u r a l f requencies and damping r a t i o s a r e derived from vector diagrams /I/. This method, l i k e a l l s teady-state methods, is tedious and time-consuming and cannot be r e a d i l y appl ied ou ts ide t h e labora tory ; a l s o , considerable expense may be incurred i f a lengthy t e s t programme is required i n order t o i n v e s t i g a t e t h e c h a r a c t e r i s t i c s of a bui l t -up s t r u c t u r e . The quasi-s teady-state t e s t method may reduce some t e s t t ime; here , t h e e x c i t a t i o n frequency is continuously varied through t h e frequency range of i n t e r e s t . However, except with very slow sweep r a t e s , t h e measured values of n a t u r a l f requencies and damping r a t i o s derived from such a t e s t a r e inaccurate because t h e assumption t h a t t h e system response a t t a i n s t r u e s teady-s ta te l e v e l s is not usua l ly v a l i d .

A novel laser scanning camera

Abstract: A camera has been developed for low light level, high resolution viewing and uses a HeNe laser beam raster-scanned across the field-of-view. By synchronously detecting the reflected light with a photomultiplier the subject can be reconstructed in a video frame and viewed on a conventional television monitor. Advantages of this system include large depth-of-field, electronic zoom, on- or off-axis optical zoom, ability to view at ranges greater than 10 m in regions that are difficult to illuminate, such as nuclear reactor gas ducts, and resolution better than 200 μm in the near-field.

Pseudo image generator

Abstract: PURPOSE:To improve the image resolution of a target image and to increase the contrast of the target image of a remote place, by providing a video projector and a zoom lens for each target image when an image of a periscope, etc. of a submarine simulator, is produced. CONSTITUTION:The images produced at target image producing parts 1-3 are delivered in the form of video signals 4-6 having a full size of a screen respectively. These signals 4-6 are converted into optical signals by video projector 18-20 also in the form of target images of a full size of the screen. The sizes of these optical signals are controlled by zoom lenses 24-26 to project images ok the screen 27. These images on the screen are viewed by human eyes via an optical system 16.

Improvements in or relating to apparatus for viewing films

Abstract: A film to be viewed is supported in a clamp 14 and is illuminated by light 13 and viewed by video camera 15 connected to a visual display monitor 16 for displaying the view on screen 18. Manual or electric controls 22 are provided. A slave monitor 19 can be used. The camera can rotate to view the film in different orientations, or two fixed cameras can be used. The camera may view the film by reflected light. The camera may have focus change and zoom facilities.

Projection inspecting machine

Abstract: PURPOSE:To select the magnification arbitrarily, by utilizing the reflected light or transmitted light from a work, and expanding and forming work configuration on a screen CONSTITUTION:A power source 1, a mounting table 2 for mounting the work, and a zoom type converging lens 13A are provided A lighting device 13 which illuminates the work on he mounting table 2 and the zoom type projecting lens 15A are provided A projecting device 15 expands and forms the work configuration on he screen 4 by utilizing the reflected light and the transmitted light from the work A magnification detecting device 6 detects the magnification of the zoom type projecting lens 15A A driving device 7 drives and sets the zoom type converging lens 13A to an illuminating range position corresponding to the preset magnification of the zoom type projecting lens which is detected by said magnification detecting device 6

Industrial television device

Abstract: PURPOSE:To orient a television camera to a pickup target automatically and accurately only with a simple operation, by designating the pickup target to be picked up among plural targets displayed on a display of a radar. CONSTITUTION:The operator make a designating spot on a display screen 3 on the display screen 3 coincident with the pickup target 5 with a joy stick, therefore a designation signal is outputted from a designation section 4 to a processing section 6, and an angle of elevation theta and an azimuth psi between a camera 10 and the target 5 are calculated according to the following formula by the processing section 6, based on the coordinates (TX, TY) on the display screen 3 for the target 5. The section 6 calculates the distance between the camera 10 and the target 5 based on the coordinates (TX, TY) of the target 5 and the optimum zoom amount of the camera 10 based on the distance. The 1st processing signal comprising the data of theta and psi calculated at the section 6 is outputted to the 1st control section 7 and the 2nd processing signal comprising the optimum zoom data is outputted to the 2nd control section 11, a drive control signal is outputted from the 1st control section 7 to the drive section 9, the drive section 9 is operated and the camera 10 is oriented on the target 5 quickly, automatically and accurately.

Simple Quasi-Zoom With Stable Pupils

Abstract: In conventional zoom systems with the aperture stop located to the rear of the moving components, the entrance pupil position varies greatly during zooming. A simple system of three positive elements, is described which can be used as a dual focal length quasi- zoom lens, which for a rear-positioned aperture stop, has a constant entrance pupil at the zoom extremes. The system may also be employed as a true zoom with limited excursion of the entrance pupil between the zoom extremes. The system is useful as a zoom relay stage in a periscope or where a prism or mirror is located at the entrance pupil to scan the line of sight.IntroductionIn conventional zoom systems the movements of the various lens elements are controlled such that the image plane remains in a fixed position as the magnification varies. The entrance and exit pupils are usually not controlled and for a fixed aperture stop, the position of the entrance pupil varies as the magnification varies. This variation in position is undesirable in many cases, for example in an image relay stage of a periscope or in a system employing a prism or mirror to provide line of sight elevation and azimuth control. Hopkins has shown that in a true zoom system (i.e. one which provides continuous variation in magnification), three separate moving elements are necessary for constancy of both image and pupil positions. It is possible, however, to achieve constant image and pupil positions at the zoom extremes with a single moving element. The system is a simple dual power optical system with stationary image and pupils. By moving a second element we have a true zoom system with quasi stationary pupils.

Zoom lens barrel of fiberscope

Abstract: PURPOSE:To obtain a zoom lens barrel which is suitable for incorporating it to the tip part of a fiberscope, by providing a gear ring being a zoom driving means, irrespective of movement of a zoom ring in the optical axis direction. CONSTITUTION:When a wire 12 is drawn, a straight ring 4 moves to the right side against a compression spring 11, and a zoom ring 3 also moves as one body. A key member 3e moves in a key groove 7b, lens groups G1-G3 move to the right side, the lens group G3 approaches the end face of an image fiber 8, and when the wire 12 is loosened, the lens group G3 recedes in the distance by the compression spring 11, and focusing is executed. Subsequently, when a pulley 14 is rotated by operating a wire 15, a gear ring 7 meshed with a small gear 13 rotates, the zoom ring 3 rotates through the key member 3e and the key groove 7b, pins 5a, 6a go straight along straight grooves 4a, 4b, lens rings 5, 6 move in the optical axis direction, and the zoom operation is performed. Accordingly, this zoom lens barrel is suitable for incorporating it to the tip of a fiberscope.

A technique for zoom transform and long-time signal analysis

Abstract: Reviews a useful technique for performing zoom transforms. The method involves recording a long-time signal and transforming it in parts, using a smaller transform. Its ability to handle long-time signals renders the method attractive to both acousticians and vibrations engineers. Examples and the listing of a computer program are given to demonstrate the technique

Interactive image processing for observer performance enhancement

Abstract: Image processing techniques may be applied to assist a human observer in TV-reconnaissance tasks. Various enhancement methods have been investigated experimentally with regard to their measurable influence on observer performance. Global contrast enhancement by means of linear histogram stretching proved to be most suitable in target detection, in comparison with histogram equalization or histogram hyperbolization. In case of target classification local enhancement techniques and zoom operations resulted in an essential increase of observer performance. When implementing interactive image processing techniques in observation tasks the design of a convenient man-machine interface is a focal point. An operator station is put forward, whereby an observer may specify procedures and parameters by means of interactive tools (joystick, lightpen, function keys) using a user-guiding menu technique.

Two-operation zoom lens capable of macrophotography

Abstract: PURPOSE:To obtain a two-operation zoom lens, which is superior in optical capacity and is capable of macrophorography, with simple constitution, by providing an engaging device which drives a focusing lens driving device and a zooming lens driving device as one body for macrophotography. CONSTITUTION:When a camera is focused to a short distance in case of macrophotography, a zoom ring 14 is slid forward (to the object side). Then, a forked part 14c of the zoom ring 14 is engaged with a projection 6d to rotate the zoom lens 14, and a barrel 6 is rotated also as one body. A rotation limiting ring 7 is pressed forward against a spring by sliding of the zoom ring 14 and is disengaged from a projection 6c. At this time, when the zoom ring 14 is rotated, a variator lens 3 and a compensator lens 4 are moved straight in the direction of the optical axis by the rotation of a zoom cam 12. The barrel 6 is rotated together with the zoom ring 14 as one body, and a focusing lens is moved also in the direction of the optical axis, and the camera is focused to the short distance. Consequently, the constitution is simple and the capacity is excellent.

Speed control servo circuit of zoom lens

Abstract: PURPOSE:To permit optional changing of the telphoto end and wide end of a zoom lens, and to make zooming operation fast by adding a window comparator, etc. to a speed control servo circuit. CONSTITUTION:A switch SW1 is turned on to connect a window comparator consisting of operational amplifiers 2 and 3 to a servo circuit. When a servomotor M is driven by the operations for setting of potentiometers P2-P4, the input terminal voltage of an amplifier 1 is made zero by the bias applied upon a diode D1 and the motor M stops. In this case, the zoom lens operates as a speed control type servo between the set value W1 and a telephoto position T1, and operates as an optionally settable position control type servo circuit at the value W1 and the position T1.

A graphical approach to documentation and implementation of control systems

Abstract: A graphics-based information system for process control applications is presented. All pieces of information, such as plant documentation, controller structures, control algorithms and run-time data, are positioned on virtual screens. The user selects the information to be presented on his monitor by “moving” in front of these screens using joysticks. Hierarchically structured information is handled by “information zooming”. Block diagrams built up by a graphical editor is interpreted by the system.