Showing papers on "Digital camera published in 1990"
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TL;DR: A low-noise digital camera based on a 512 x 96 element CCD operating in the time-delay integration mode combined with an x-ray image intensifier to record radiographic images produced by a scanning slot beam of radiation is developed.
Abstract: We have developed a low‐noise digital camera based on a 512×96 element CCD operating in the time‐delay integration mode. This camera has been combined with an x‐ray image intensifier to record radiographicimages produced by a scanning slot beam of radiation. This results in the rejection of a large fraction of scattered radiation, without a significant increase in x‐ray tube heat loading or image acquisition time. Here we describe the design of our CCDcamera and the results of our investigations of camera resolution, linearity, noise, and quantum efficiency. We have found that both the resolution limit (50 mm−1) and the dynamic range (2100) of this novel camera are greater than reported values for conventional video cameras. Applications of this system in digital angiography and mammography are discussed.
70 citations
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09 Oct 1990TL;DR: In this article, a digital camera apparatus has an analog emphasis circuitry arranged such that when an output from a charge-coupled device (CCD) forming the imager and cooperating with a complementary color, checkered pattern filter is processed in a digital fashion, an analog carrier chrominance signal component is emphasized before being converted to a digital signal, thus making it possible to reduce adverse influence caused by quantization noise.
Abstract: A digital camera apparatus has an analog emphasis circuitry arranged such that when an output from a charge-coupled device (CCD) forming the imager and cooperating with a complementary color, checkered pattern filter is processed in a digital fashion, an analog carrier chrominance signal component is emphasized before being converted to a digital signal, thus making it possible to reduce adverse influence caused by quantization noise.
16 citations
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16 Jun 1990
TL;DR: The geometric model, and the calibration procedure are demonstrated by calibrating the EIKONIX (EC850) camera, and are useful for aerial photograph analysis, machine vision, and digital photogrammetry.
Abstract: An algorithm is proposed for accurate camera calibration. Attention is focused on finding a suitable distortion model for a digital camera. The geometric model, and the calibration procedure are demonstrated by calibrating the EIKONIX (EC850) camera. Several experiments are made with an average control point location error of about 6.6 mu m and 1/40000 over the field of view. The results obtained are useful for aerial photograph analysis, machine vision, and digital photogrammetry. >
5 citations
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11 Oct 1990TL;DR: In this article, a digital camera apparatus has an analogue emphasis circuit arranged such that when an output from a charge-coupled device forming the imager and cooperating with a complementary color, checkered pattern filter is processed in a digital fashion, an analogue carrier chrominance signal component is emphasized before being converted to a digital signal.
Abstract: A digital camera apparatus has an analogue emphasis circuit (26) arranged such that when an output from a charge-coupled device (21) forming the imager and cooperating with a complementary colour, checkered pattern filter (10) is processed in a digital fashion, an analogue carrier chrominance signal component is emphasized (26) before being converted to a digital signal.