SRI International (SRI) has developed a new multi-purpose day/night video camera with low-light imaging performance comparable to an image intensifier, while offering the size, weight, ruggedness, and cost advantages enabled by the use of SRI’s NV-CMOS HD digital image sensor chip. The digital video output is ideal for image enhancement, sharing with others through networking, video capture for data analysis, or fusion with thermal cameras. The camera provides Camera Link output with HD/WUXGA resolution of 1920 x 1200 pixels operating at 60 Hz. Windowing to smaller sizes enables operation at higher frame rates. High sensitivity is achieved through use of backside illumination, providing high Quantum Efficiency (QE) across the visible and near infrared (NIR) bands (peak QE <90%), as well as projected low noise (<2h+) readout. Power consumption is minimized in the camera, which operates from a single 5V supply. The NVCMOS HD camera provides a substantial reduction in size, weight, and power (SWaP) , ideal for SWaP-constrained day/night imaging platforms such as UAVs, ground vehicles, fixed mount surveillance, and may be reconfigured for mobile soldier operations such as night vision goggles and weapon sights. In addition the camera with the NV-CMOS HD imager is suitable for high performance digital cinematography/broadcast systems, biofluorescence/microscopy imaging, day/night security and surveillance, and other high-end applications which require HD video imaging with high sensitivity and wide dynamic range. The camera comes with an array of lens mounts including C-mount and F-mount. The latest test data from the NV-CMOS HD camera will be presented.
Traditionally, daylight and night vision imaging systems have required image intensifiers plus daytime cameras. But SRI’s new NV-CMOS™ image sensor technology is designed to capture images over the full range of illumination from bright sunlight to starlight. SRI’s NV-CMOS image sensors provide the low light sensitivity approaching that of an analog image intensifier tube with the cost, power, ruggedness, flexibility and convenience of a digital CMOS imager chip. NV-CMOS provides multi-megapixels at video frame rates with low noise (<2 h+), high sensitivity across the visible and near infrared (NIR) bands (peak QE <85%), high resolution (MTF at Nyquist < 50% @ 650 nm), and extended dynamic range (<75 dB). The latest test data from the NV-CMOS imager technology will be presented.
Unlike conventional image intensifiers, the NV-CMOS image sensor outputs a digital signal, ideal for recording or sharing video as well as fusion with thermal imagery. The result is a substantial reduction in size and weight, ideal for SWaP-constrained missions such as UAVs and mobile operations. SRI’s motion adaptive noise reduction processing further increases the sensitivity and reduces image smear. Enhancement of moving targets in imagery captured under extreme low light conditions imposes difficult challenges. SRI has demonstrated that image registration provides a robust solution for enhancing global scene contrast under very low SNR conditions.
An advanced surveillance/security system is being developed for unattended 24/7 image acquisition and automated
detection, discrimination, and tracking of humans and vehicles. The low-light video camera incorporates an electron
multiplying CCD sensor with a programmable on-chip gain of up to 1000:1, providing effective noise levels of less than
1 electron. The EMCCD camera operates in full color mode under sunlit and moonlit conditions, and monochrome under
quarter-moonlight to overcast starlight illumination. Sixty frame per second operation and progressive scanning
minimizes motion artifacts. The acquired image sequences are processed with FPGA-compatible real-time algorithms,
to detect/localize/track targets and reject non-targets due to clutter under a broad range of illumination conditions and
viewing angles. The object detectors that are used are trained from actual image data. Detectors have been developed
and demonstrated for faces, upright humans, crawling humans, large animals, cars and trucks. Detection and tracking of
targets too small for template-based detection is achieved. For face and vehicle targets the results of the detection are
passed to secondary processing to extract recognition templates, which are then compared with a database for
identification. When combined with pan-tilt-zoom (PTZ) optics, the resulting system provides a reliable wide-area 24/7
surveillance system that avoids the high life-cycle cost of infrared cameras and image intensifiers.
A family of monochrome, high-speed linear imagers has been developed with each device to be available as a single chip fabricated using a standard commercially available CMOS process. Currently, the 2048 pixel device has been fabricated using a 0.5-micron CMOS process and its architecture, functionality and performance is described. The family of imagers features a unique combination of high functional integration, very high speed, low dark current, high sensitivity and high pixel-to-pixel uniformity. The pixels are 7.0 microns by 7.0 microns and have 100 percent fill factor. The high pixel-pixel uniformity is made possible by using low dark current pixels, a correlated double sampler circuit per pixel and a fully differential video bus. High functional integration is enabled by on-chip logic that is provided to minimize support circuitry and simplify application. Included are several exposure modes that provide full-frame electronic shutter, independent control of integration time and simultaneous integration and read-out. Only 5 volts DC and clock signal running at twice the desired pixel rate are required for basic operation. Low dark current and high sensitivity result from a novel pixel and low-noise preamplifier structure. A novel video multiplexing structure provides the very high read-out speed of 60 Mpixel/sec per 2048 pixel segment while sustaining an MTF of 50 percent at 35 line pairs per millimeter.
The first section will review the requirements for scientific/industrial cameras and discuss the limitations of conventional CCD and active pixel sensors (APS) approaches. The next section will describe the Active Column Sensor technology, and discuss the reasons for the improved performance compared to passive pixel CMOS and APS imagers. Then the Active Column SensorTM (ACS) pixel structure and modes of pixel operation will be discussed. The paper will also describe the other camera functions that are placed on the same substrate. Experimental results including images will be presented. The paper will close with a glimpse into the future of industrial and scientific CMOS ACS image enabled systems.
The system we have been investigating is a real-time portal imager which incorporates an x-ray-to-light converter and a CCD sensor. When the high-energy X-rays of the radiation therapy beam circumvent the converter and impinge directly on the CCD sensor they cause artifacts in the image that have the appearance of scattered bright points of light. It is as if salt has been shaken onto a photograph. In therapy imaging the artifact is termed 'direct hit' noise. The generic name impulse noise. The goal of this investigation has been to determine an efficient method for eliminating 'direct hit' artifacts produced on a CCD camera in a portal imaging system. Because the photon energies for portal imaging are so high, it is very difficult to prevent the hits. For that reason, we have investigated post-processing methods to remove the noise from captured images. Two families of filtering algorithms are applied in the images: A wavelet-based family and a rank-order based family.
Image quality in digital fluoroscopic and angiographic systems has been limited by camera resolution and image processing capabilities especially for large fields of view. An intense research and development effort has led to an increase in the resolution performance of a digital image system designed for fluoroscopy and angiography applications. The result of this effort has been recently realized by the introduction of a 2000 line digital fluoroscopic/angiographic x-ray system capable of processing 20482 digital images at 7.5 frames per second. This paper presents the latest theoretical information and recently obtained clinical results demonstrating the improvement in resolution performance compared with the traditional 1000 line system. Several recent technological advances in the performance of image intensifiers, camera tubes, display monitors, and the semiconductor industry have enabled cost-effective solutions to earlier obstacles to 2000 line imaging. The various components of the 2000 line digital fluoroscopic imaging system affecting resolution are presented individually with emphasis on the total impact on system performance. These key components include large field of view image intensifiers, camera tubes, optics, image displays, hardcopy devices and image processing hardware. The processing hardware referenced in this paper is described in detail in a paper titled '2048 Line by 2048 Pixel High- Speed Image Processor for Digital Fluoroscopy' which is presented in the Image Display section of this conference. The MTF characteristics of these various components are illustrated and used to demonstrate their impact on the clinical images displayed on the monitor or hard copied on a laser printer. The results presented in this paper demonstrate the improvement in resolution performance with increased visibility of image details of clinical benefit that can be realized from a 2000 line digital fluoroscopic imaging system when compared with traditional 1000 line systems.