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Dynamic range

About: Dynamic range is a research topic. Over the lifetime, 7576 publications have been published within this topic receiving 101739 citations. The topic is also known as: DNR & DR.


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Patent
06 Mar 2002
TL;DR: In this paper, the least significant bits of one or more output samples of a particular processing stage, having finite word widths, while avoiding the loss of most significant bits are preserved.
Abstract: Precision of multi-stage digital signal processing is increased by preserving least significant bits of one or more output samples of a particular processing stage, having finite word widths, while avoiding the loss of most significant bits. The technique is applicable to one or more stages of multi-stage digital signal processing, thereby increasing precision therein and the signal-to-noise ratio. A plurality of output samples are calculated using a plurality of input samples, and the dynamic range of one or more of the output samples is decreased if the output sample can be represented in a smaller dynamic range without losing a significant bit. The input samples of a particular stage, obtained from the output samples of a previous stage, may further be normalized so that the input samples are represented in the same dynamic range before being processed.

36 citations

Proceedings ArticleDOI
29 May 2009
TL;DR: Key elements for machine vision are the intra-scene dynamic range of the optical front-end, and a data representation that is as independent as possible from the illumination level, which enables a single-chip vision system to perform image acquisition, analysis and decision-making.
Abstract: Key elements for machine vision are the intra-scene dynamic range of the optical front-end, and a data representation that is as independent as possible from the illumination level. Furthermore, combining an optical front-end and a processor on the same chip enables a single-chip vision system to perform image acquisition, analysis and decision-making. Approaches that enable high dynamic range are logarithmic imagers [1] and lin-log imagers [2], but they suffer from poor fixed-pattern noise (FPN) performance [1,2] and non-uniform transfer functions [2] due to the combination of linear and logarithmic domains. While multiple-exposure imagers [3] solve the FPN problem, they require post-processing to combine several frame captures. Finally the dynamic range of time-domain logarithmic imagers with fixed reference voltages [4] is limited by the maximum allowable exposure time.

36 citations

Journal ArticleDOI
TL;DR: The proposed method with its large dynamic range and measurement versatility can be applied to a broad range of applications, including microscopic structures, objects with large size or aspect ratio, and ultrafast time-resolved imaging.
Abstract: A simultaneously high-precision, wide-range, and ultrafast time-resolution one-shot 3D shape measurement method is presented. Simultaneous times of flight from multiple positions to a target encoded in a chirped optical frequency comb can be obtained from spectral interferometry. We experimentally demonstrate a one-shot imaging profile measurement of a known step height of 480 µm with µm-level accuracy. We further demonstrate the extension of the dynamic range by measuring in one shot a large step height of 3 m while maintaining high accuracy using the accurate pulse-to-pulse separation of the optical frequency comb. The proposed method with its large dynamic range and measurement versatility can be applied to a broad range of applications, including microscopic structures, objects with large size or aspect ratio, and ultrafast time-resolved imaging. This study provides a powerful and versatile tool for 3D measurement, where various ranges of measurement performances can be tailored to demand.

36 citations

Patent
31 May 2007
TL;DR: In this article, a method of increasing the dynamic range of an image comprising a plurality of pixels each having a luminance value within a first luminance dynamic range is proposed, which includes determining a background luminance values for each pixel of the image and determining a minimum and a maximum of the background luminances values.
Abstract: A method of increasing the dynamic range of an image comprising a plurality of pixels each having a luminance value within a first luminance dynamic range. The method includes determining a background luminance value for each pixel of the image and determining a minimum and a maximum of the background luminance values. A conversion factor is then determined for each pixel of the image based on the minimum and maximum of the background luminance values. The image id converted from the first luminance dynamic range to a second luminance dynamic range by multiplying the luminance value of each pixel of the image by its conversion factor.

36 citations

Journal ArticleDOI
Hui Zhang1, Lin Li, Ke Wu
TL;DR: A software-defined radar measurement system on the basis of a six-port receiver technique is proposed and accurate range results are confirmed.
Abstract: A software-defined radar measurement system on the basis of a six-port receiver technique is proposed and described in this paper. The system makes use of a hybrid scheme of two performance-complementary operating modes, namely, frequency-modulated continuous-wave (FMCW) and two-tone continuous-wave signals. Generally, the FMCW-based measurement technique is deployed to give an approximate range value of target while the two-tone continuous-wave (CW)-based measurement technique can accurately determine the range that may, however, be ambiguous. The six-port circuit is used for the receiver as a precision phase detector in two-tone CW function and at the same time as a mixer in FMCW function. Various waveforms are generated in direct digital synthesizers and processed by different algorithms in a digital signal processor. The switching between the frequency-modulated CW and two-tone CW functions is controlled by software to improve the resolution and ensure a reliable operation. A system prototype is designed and made for a C-band demonstration. The Schottky diodes used as power detectors in the six-port are calibrated so that they can be used beyond the square-law region, thus allowing a higher power level and a better dynamic range. Measured results validate the proposed software-defined platform and accurate range results are confirmed.

35 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023176
2022383
2021189
2020265
2019325
2018334