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Showing papers by "AT&T Labs published in 1992"


Patent
18 Feb 1992
TL;DR: In this paper, the authors propose a network comprising a plurality of successively interconnected node stages where each node has an associated data connection state and includes a control element, significantly implemented as part of the node itself, for controlling the data connection states of at least one node of the following stage.
Abstract: A network comprising a plurality of successively interconnected node stages where each node has an associated data connection state and includes a control element, significantly implemented as part of the node itself, for controlling the data connection state of at least one node of the following stage. The network is well suited for optical implementation and is controlled by shifting bits into the network for storage by the control elements rather than relying on spatial light modulators.

17 citations


Proceedings ArticleDOI
12 Aug 1992
TL;DR: 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.
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.

13 citations



Proceedings ArticleDOI
D.A.B. Miller1
29 Jul 1992

1 citations


Proceedings ArticleDOI
12 Aug 1992
TL;DR: In this article, a CCD line scan camera with a resolution of 6000 × 6000 × 12 bits per pixel per color component with a variable pixel aspect ratio was used to digitize color transparencies.
Abstract: A high-resolution imaging system employing a CCD line scan camera has been constructed with a resolution of 6000 x 6000 x 12 bits per pixel per color component with a variable pixel aspect ratio. The raw image data is processed in real time to correct for one dimensional artifacts arising from the sensor dark current signal as well as gain and integration control nonuniformities. The gain nonuniformity correction includes second order effects. Two dimensional artifacts attributable to sensor window defects are also removed. The system''s noise performance is found to be limited primarily by sensor shot noise and uncorrected sensor nonuniformities. For most images the system noise is below the visible threshold. This still imaging system has been used to digitize color transparencies up to 6 X 6cm including 35 and 70mm motion picture film for HDTV motion test sequences. 1. OVERVIEW AND DESIGN CONSIDERATIONS The CCD line scan camera described in this paper was designed as a laboratory system to be used as a source of high quality image data for visual communications research. A block diagram of the system is shown in Figure 1. The intent was to produce digital images of sufficient resolution and quality to meet the needs of HDTV researchers for the foreseeable future in fact the scanner''s resolution far exceeds that of present display technology. Output image quality was the primary design consideration and attention

1 citations


Journal ArticleDOI
TL;DR: In this article, an EBIC analysis is made of decorated heteroepitaxial misfit dislocations formed at the interface of Si-Si(Ge) epitaxial layers grown in a CVD reactor on Si substrates.
Abstract: An EBIC analysis is made of decorated heteroepitaxial misfit dislocations formed at the interface of Si-Si(Ge) epitaxial layers grown in a CVD reactor on Si substrates. The electrical activity of the dislocations is studied after decorating the dislocations with Ni and Au impurities introduced by ion-implantation and backside deposited metallic thin films. The impurities are activated by RTA annealing at 400, 800 and 1000°C. A model is presented for the formation of NiSi2 precipitates on misfit dislocations which suggests that the nucleation and growth of NiSi2 precipitates is a function of the cleanliness of the as-grown dislocations. It is concluded that the distribution of electrical activity of impurity decorated misfit dislocations is a strong function of the impurity type, condition of the as-grown material, and concentration of metallic impurities introduced during the process of decoration.