Topic
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.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this article, a TFA image sensor consists of an amorphous silicon based multilayer structure on top of a crystalline ASIC, which acts as the optical detector and performs analog or digital signal processing for each individual pixel.
Abstract: A TFA image sensor consists of an amorphous silicon based multilayer structure on top of a crystalline ASIC. The Multilayer acts as the optical detector, whereas the ASIC performs analog or digital signal processing for each individual pixel. Depending on the operation Mode, the dynamic range of the detector exceeds the performance of conventional CCDs by far. Pixel electronics which is adapted to the requirements of the detector can thereby maximize the dynamic range of the complete sensor array. Crosstalk among adjacent pixels can be eliminated by technological or electronic Means.
31 citations
TL;DR: In this paper, a novel approach to obtain interference phase measurements using sinusoidal modulation in order to obtain high resolution data at high temporal bandwidths is presented. But the use of classical phase stepping techniques generates ringing in PZT-based phase modulators and hence limits the temporal bandwidth at which reliable phase data can be obtained.
Abstract: In this paper we present a novel approach to obtain interference phase measurements using sinusoidal modulation in order to obtain high resolution data at high temporal bandwidths. The use of classical phase stepping techniques generates ringing in PZT-based phase modulators and hence limits the temporal bandwidth at which reliable phase data can be obtained. Signal processing techniques are introduced to extract intensity measurements at any required phase step and hence offer compatibility with existing linear phase shifting interferometry algorithms. It was found that, under high frequency and/or high amplitude sinusoidal excitation, the PZT phase modulator could exhibit a nonlinear response. Strategies are introduced to mitigate these effects on the calculated interference phase. Experimental data is presented demonstrating a phase resolution of 1/600th of a fringe at a temporal bandwidth of 8150 Hz when using the Carre phase stepping algorithm. Data from a multi-wavelength fibre interferometer with sinusoidal modulation to obtain the wrapped phase measurements are also presented where a dynamic range of 1 part in 2 × 106 was achieved.
31 citations
Patent•
03 May 1993
TL;DR: In this paper, an imaging apparatus capable of expanding a dynamic range image signals of different levels are read simultaneously from a solid-state element whose light-receiving surface is divided.
Abstract: In an imaging apparatus capable of expanding a dynamic range image signals of different levels are read simultaneously from a solid-state element whose light-receiving surface is divided. Read 1/2 frame image signals are switched by a changeover switch circuit at intervals of a 1/2 frame time. One of two image signals of different levels supplied from the two outputs of the changeover switch circuit is delayed at a delay circuit. Further, those image signals are separated into r, g, and b components, and then undergo logarithmic conversion into image signals of multiple desired levels. The signals are digitized at an A/D converter and undergo operations at an adder, which adds while keeping their logarithmic characteristic, and at an inverse logarithmic converter. A luminance signal is obtained at a matrix circuit, and is converted into a logarithm at a logarithmic circuit. The lighting irregularity components of the resulting signal are suppressed. This signal is compressed, and the compressed signal is subtracted at a subtracter to obtain a compression coefficient, which is added to the digitized image signal from the A/D converter. Image signals of a wide dynamic range corrected at the inverse logarithmic converter are obtained for a single image at a TV rate on a real-time basis. Further, the control of exposure to the entire image and the expansion of the dynamic range are possible.
31 citations
TL;DR: In this paper, the authors defined the dynamic range of a spectrum as the ratio of the highest peak to the lowest peak of interest, and any lineshape intensity can be defined to be the inverse of the intensity of the spectrum.
31 citations
TL;DR: The optical differentiation wavefront sensor, consisting of an amplitude mask placed at the intermediate focal plane of a 4-f setup, is described, which shows that, even in adverse low-light-level conditions, its SNR compares quite well to that corresponding to the Hartmann-Shack sensor.
Abstract: High resolution wavefront sensors are devices with a great practical interest since they are becoming a key part in an increasing number of applications like extreme Adaptive Optics. We describe the optical differentiation wavefront sensor, consisting of an amplitude mask placed at the intermediate focal plane of a 4-f setup. This sensor offers the advantages of high resolution and adjustable dynamic range. Furthermore, it can work with polychromatic light sources. In this paper we show that, even in adverse low-light-level conditions, its SNR compares quite well to that corresponding to the Hartmann-Shack sensor.
31 citations