Showing papers on "Three-CCD camera published in 1992"

An analysis of camera noise

Abstract: The class of cameras that are based on ionization sensors, which includes the most common charge-coupled device (CCD) and vidicon cameras, is examined. Camera signals are shown to be corrupted by direction-dependent stationary electronic noise sources and fluctuations due to the statistical nature of the sensing process. The authors develop and test a model of the inherent noises in cameras. These results are confirmed by measurement, and they suggest a locally stationary model of noise for adaptive signal processing. >

Color parallax-free camera and display

Abstract: Improved image quality is realized in a parallax-free teleconferencing display by increasing the camera light budget, that is, by increasing the light available to the camera, while maintaining a common optic axis between the camera and the display screen. Light-attenuating devices, such as color filters, are repositioned out of the path of light entering the camera. In this manner, image quality is improved while color capability is maintained.

Video temperature monitor

Abstract: An apparatus and method for providing a real-time video display and a temperature map display of an object, in particular a flame, comprises a single CCD video camera and optical equipment which focuses separate light bundles onto a photosensitive surface of the camera. A separate band pass filter is used in each light bundle to filter selected different wavelengths of light. The video signal from the camera is used in a video digitizer to obtain data which can be used to calculate a temperature map based on the different wavelengths of light of the two bundles. The video signal is also used to produce a real-time video display of the object.

Setting-up system for remotely controlled cameras

Abstract: In a remote control system for one or more robotic cameras (18), in which a camera can be moved between stored positions, a frame of video is grabbed and stored for each stored camera position, and the stored pictures are displayed on a monitor (26). Selection of a desired camera position is then made by selecting the appropriate displayed picture, for example using a mouse (28), light pen or touch screen.

Water-proof camera case and detachable hand grip assembly

Abstract: A camera case which permits underwater video shooting and which is also useful in video shooting on the ground when a hand grip assembly is detached therefrom. In the event of underwater video shooting, a video camera is placed in a main case body 10, and grips 41 and 42 are attached to the case through a link plate 43. The grip 41 functions as a remote control transmitting infrared control signals from an LED to a signal receiver within a transparent window 38 on the camera case 10 to operate the camera accordingly. When using the camera case as a water-resistant case in video shooting on land, the link plate 43 may be detached from the camera case 10, and the camera is operated by way of buttons on the camera case.

Interchangeable lens type camera apparatus

Abstract: This invention discloses an interchangeable lens type video camera for deciding lens specifications on a camera side and changing control data transmitted from the camera side to a lens unit in accordance with specifications of the lens unit, thereby performing optimal control. A video camera is also disclosed in which an adapter for mounting a lens unit on the video camera is arranged, and control data outputted from the video camera side to the lens unit is corrected in accordance with lens characteristics, thereby performing the same operation as in a case wherein a video camera lens is mounted on the video camera.

Web defect continuous surveillance system

Abstract: A video surveillance system for monitoring a continuous web of material negotiating the tortuous path through a paper making machine employs a plurality of video cameras for the continuous monitoring of the web arranged in pairs, each pair addressing a different location of interest along the paper making path. All of the cameras are operated using a single external sync signal and produce video output signals which, in turn, are fed to a plurality of video image splitters, each splitting the video output from a pair of cameras. Video recorders are provided for recording and playing back the split video output signals from each video image splitter through video monitors. The system is computer controlled and responsive to input signals indicative of web failure.

Combination of water-proof camera case and detachable hand grip assembly

Abstract: Disclosed herein is a camera case which permits underwater video shooting and which is also useful in video shooting on the groun when a hand grip assembly is detached therefrom. In the event of underwater video shooting, a video camera 14 is placed a.n a main case body 10, and grips 41 and 42 are attached to the case through a link plate 43. The grip 41 has the functions as a remote commander, transmitting infrared control signals from an LED to a signal receiver 35 within a transparent window 38 on the camera case 10 to operate the camera 14 accordingly. At the time of using the camera case as a drip-proof case in video shooting on the ground, the link plate 43 is detached from the camera case 10, and the camera 14 in the case is operated by way of operating buttons 24 to 26 on the camera case.

System for recording identical electronic and photographic images

Abstract: Apparatus for recording a video image which is identical to a photograph of a person includes a video camera for making a video image and a photographic camera having an openable shutter for exposing a piece of film for taking a photograph. A computer is operatively connected to the photographic camera and to the video camera for sending a take signal to the photographic camera at a predetermined time before sending a take signal to the video camera, the predetermined time being equal to the length of time required to open the shutter. Thus the photographic camera takes a photograph which is identical to the video image recorded by the video camera, because the photographic camera and the video camera respond to their respective take signals at the same time.

Electro-optical control of light attenuation in the optical path of a camera

Abstract: A camera which has an electrochromic neutral density filter. The neutral density filter is placed in the optical path of the camera. The filter changes the amount of light which may pass through it when a voltage is applied thereby regulating the amount of light which may enter the camera. By controlling the amount of light which passes through the electrochromic filter, the camera operator can control incoming light to maintain desired density (depth of field). In another embodiment, a color video camera has a color separator which separates the light into red, green and blue components. Electrochromic filters are placed between the color separator and red and blue light sensors of the camera to control the amount of light reaching the red and blue sensors. By controlling the amount of light which passes through the electrochromic filters, the camera operator can control incoming light to correct color.

White balance target

Abstract: A target for use in white balancing video cameras and, in particular, video cameras suitable for endoscopic use. The target is molded from an elastomeric material having the ability to diffuse a substantial portion of light incident upon the target from a video camera. A user may use the target to white balance a video camera by placing the camera directly on the target and adjusting the light intensity of the camera's light source. In the case of an endoscopic camera, the distal tip of the scope (extending from the camera) is placed directly on the target. The user need not be concerned about aiming the camera at a selected white target and holding it a certain distance from the target.

How to select cameras for machine vision

Abstract: Solid state (CCD, CID, or multiplexed photosensor) television cameras are the most widely used input devices in machine vision, because they are relatively inexpensive, rugged, and reliable. However, the design, specification, and testing of these cameras typically are geared to their primary use in producing images that will ultimately be observed by humans; the intended applications for these cameras are as diverse as parking lot security and home entertainment. Because the video information produced by the camera is not used in the same ways by people and machine vision systems, there is no a priori reason to expect that a camera designed for one use will be optimal for another. In our work we have examined what makes a camera suitable for machine vision use. This paper describes which characteristics are important to the camera's performance machine vision applications and why. We show how these characteristics can be measured and standardized using simple tests suitable for production screening or more extensive tests suitable for use in the laboratory. Tests for important camera characteristics, including transfer function, noise, and resolution, are described and test results for representative solid state cameras are presented. Finally, we discuss how such measurements can be useful in designing or selecting the components of a machine vision system: the video capture systems, the cameras, and the image processing algorithms.

Improving the color fidelity of cameras for advanced television systems

Abstract: In this paper we compare the accuracy of the color information obtained from television cameras using three and five wavelength bands. This comparison is based on real digital camera data. The cameras are treated as colorimeters whose characteristics are not linked to that of the display. The color matrices for both cameras were obtained by identical optimization procedures that minimized the color error The color error for the five band camera is 2. 5 times smaller than that obtained from the three band camera. Visual comparison of color matches on a characterized color monitor indicate that the five band camera is capable of color measurements that produce no significant visual error on the display. Because the outputs from the five band camera are reduced to the normal three channels conventionally used for display there need be no increase in signal handling complexity outside the camera. Likewise it is possible to construct a five band camera using only three sensors as in conventional cameras. The principal drawback of the five band camera is the reduction in effective camera sensitivity by about 3/4 of an I stop. 1.

Process and arrangement for optical quality control and/or classification of plants

Abstract: For the automatic optical quality control and/or classification of plants, an electronic colour camera takes a picture of a plant from above and an electronic half-tone camera takes a picture of the plant from the side. The electric image signals provided by each camera are digitised and evaluated by an image computer to determine characteristics of the plant. The height of the plant, in particular, can be found via the half-tone camera. Each camera has a light source. In order to prevent the mutual impairment of the images and their evaluation, each camera is preferably so constructed that it is insensitive to the light from the light source allocated to the other one. Mutual impairment can also be avoided by causing a control circuit to switch the two light sources on alternately and trigger the pictures taken of the plant by each camera at a time at which only the light source allocated to the camera is switched on.

CCD camera as a tool for color measurement

Abstract: The use of video cameras based on charge-coupled devices (CCD's) for color measurement is a new and growing field which does not fit into any established category of image processing. Just as silicon photodiodes replaced photomultiplier tubes in colorimeters twenty years ago, the CCD array is beginning to replace the silicon diode today. A good colorimeter has a measurement repeatability of the order of 1 part in 10,000, or 0.01 in XYZ or L*a*b*. By contrast, most video frame grabbers are limited to a resolution of 1 part in 256. However, because a color camera can produce in excess of 23 million 8-bit numbers per second, appropriate image processing may be used to improve repeatability and reproducibility dramatically. In this paper, the CCD camera is evaluated from the standpoint of conventional colorimetry. The following points are addressed: requirements of a camera to be used for color measurement; possible physical configurations; sources of noise and repeatability of color measurements; image processing algorithms for colorimetry; RGB-to- XYZ transformation; and requirements for an image processor to be used with a camera-based colorimeter.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Automatic camera control for AUVs: a comparison of image assessment methods

Abstract: The authors compare the performance of a spatial domain and a spatial frequency domain control method used to assess image content information from charge coupled device (CCD) camera imagery. Sample underwater images were processed using the developed techniques and are used to illustrate comparative levels of control for different water qualities, object contrasts, and ranges. The implementation algorithm required to use these techniques to control an autonomous underwater vehicle's camera light level and range-to-target distance is also presented. >

Converter for interchangeable lens type camera apparatus

Abstract: of EP0497376This invention discloses an interchangeable lens type video camera for deciding lens specifications on a camera side and changing control data transmitted from the camera side to a lens unit in accordance with specifications of the lens unit, thereby performing optimal control. A video camera is also disclosed in which an adapter for mounting a lens unit on the video camera is arranged, and control data outputted from the video camera side to the lens unit is corrected in accordance with lens characteristics, thereby performing the same operation as in a case wherein a video camera lens is mounted on the video camera.

Use of a CCD array as a medium-speed streak camera

Abstract: A 14-bit scientific CCD camera has been used as a medium-speed streak camera through software modifications that preserve the high dynamic range and excellent sensitivity characteristic of these cameras. Line shift speeds as short as 8.1 microsecond(s) ec are found to have no detrimental effects on image quality as long as light intensity is kept below saturation levels. Examples of streak images from shock tube studies of reactive systems are presented.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Camera with installation structure of lens for light measurement

Abstract: Described is a camera with an installation structure of lens for light measurement. The camera includes a camera body having a front surface to which a photographing lens is mounted, and through which a hole is formed. A light-receiving element is provided in the camera body, and a lens for light measurement is installed in the hole and has a front surface located at an objective side, for focusing an objective image light onto the light-receiving element. The front surface of the lens for light measure is positioned substantially on the same plane as the front surface of the camera body.

Video camera apparatus and lens unit for video camera

Abstract: PURPOSE: To obtain a video camera apparatus in which an operating part for area movement for focusing can be provided without increasing the number of switches or the like additionally. CONSTITUTION: In the video camera apparatus which detects a focusing state corresponding to the video signal of a partial area out of video screens formed by a two-dimensional video signal obtained by an image pickup element, a track ball 14 is provided at the lower stage part of a front plane 11 in the camera main body 10 of the video camera apparatus, and it is shared with a VTR start/stop switch. Such constitution that the partial area can be moved on the video screen by performing the rotary operation of the track ball 14 in a circumferential direction is employed. Also, the recording of the video signal on a recording medium by a recorder means can be started or stopped by performing the pressing operation of the track ball 14. COPYRIGHT: (C)1994,JPO&Japio

Device for charging camera batteries and for connecting a video camera with other electric devices

Abstract: A video camera apparatus including a video camera device (1), a battery (30) supplying electric energy to the video camera device, an adapter (40) detachably mounted on the video camera device to connect the video camera device with the battery, and a connecting device (100) for detachably mounting the video camera device thereon to connect the video camera device with another electric apparatus (80).

Matching solid state camera with frame grabber: a must for accurate gauging

Abstract: It is important to select the right solid state camera in every machine vision application. The solid state camera technical specifications, such as spectral response, signal to noise ratio, dynamic range, sensitivity, sensor type and size, horizontal, and vertical resolution are the leading criteria for sensor selection. In general, it is expected that a camera with better specifications will improve gaging accuracy of a vision system. Yet, many times the result does not meet the expectation. In some cases the system performance even decreases. The reason is that the analog output voltage from the camera is sampled asynchronously by the common industrial machine vision systems and it can resolve in worse edge deformation and mislocation for the camera with higher resolution, and better signal to noise ratio than for the camera of lower performance. In this paper, we examine this effect with particular emphasis on edge detection performance. Video sampling timing charts and achieved subpixel accuracy and repeatability, when using several common solid state cameras with the same frame grabber, are presented. The guidelines for selecting a solid state camera according to the frame grabber are provided.