Topic
High dynamic range
About: High dynamic range is a research topic. Over the lifetime, 4280 publications have been published within this topic receiving 76293 citations. The topic is also known as: HDR.
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Patent•
12 Feb 2004TL;DR: In this article, a column feedback circuit is used to suppress the read noise in a CCD-like circuit to achieve high intra-scene contracts under low illumination with high dynamic range.
Abstract: The present invention provides a CMOS imager with a reset scheme, by which a CMOS imager generates a sub-kTC noise so that read noise does not depend on the sense node capacitance. By using a column feedback circuit, reset noise can be suppressed to a negligible amount so that photogate APS or CCD-like circuits can achieve noise performance to very efficient value. This scheme allows increasing sense node capacitance without increasing the noise and also achieves a large full-well value without sacrificing read noise performance. The feedback circuit in one of the embodiment of the present invention is located at the column side of the circuit. This design provides a minimal change to the pixel. As a result quantum efficiency or pixel size is not compromised. The present invention allows a CMOS imager to capture scene with high intra-scene contracts under low illumination with high dynamic range.
24 citations
TL;DR: In this paper, a fiber-optic laser Doppler velocity sensor based on interferometric processing of a wavelength encoded signal is described and demonstrated with a dynamic velocity resolution of <80 /spl mu/m/s/s//spl radic/Hz.
Abstract: We describe and demonstrate a fiber-optic laser Doppler velocity sensor which is based on interferometric processing of a wavelength encoded signal. The range of the fiber-optic velocimeter is scalable from less than 1 mm/s up to 1000 m/s through changes in the optical path imbalance in the fiber-optic interferometer. A dynamic velocity resolution of <80 /spl mu/m/s//spl radic/Hz is demonstrated.
24 citations
TL;DR: The proposed CE algorithm based on high dynamic range (HDR) imaging makes use of different intensity information from multiple images, therefore, the performance of the proposed method is better than that of existing CE algorithms.
Abstract: Video image quality improving technologies produce remarkable achievements as display devices make rapid progress. However, there exist some limitations on intensity representation of display and acquisition devices to reproduce the real world video images. Various contrast enhancement (CE) algorithms have been developed and applied to overcome those limitations but there are many drawbacks such as color information change, loss of the lighting information, and excessive enhancement. This paper proposes a CE algorithm based on high dynamic range (HDR) imaging. First, an input image is determined whether or not it requires CE in a pre-processing step using the proposed auto exposure algorithm. Then, multiple images are generated by applying the intensity mapping function to an input image. At last, an HDR image is constructed with multiple images, in which registration of multiple images is not required. So, the proposed CE algorithm could increase the dynamic range and thus increase the contrast of an input image. The proposed CE method makes use of different intensity information from multiple images, therefore, the performance of the proposed method is better than that of existing CE algorithms. Experiments with three real images show the effectiveness of the proposed CE algorithm
24 citations
TL;DR: In this paper, a terahertz (THz) continuous-wave coherent homodyne spectroscopy and imaging system based on THz phase control using electrooptic (EO) phase modulation for fast measurement without mechanical delay movement is presented.
Abstract: We present a terahertz (THz) continuous-wave coherent homodyne spectroscopy and imaging system based on THz phase control using electrooptic (EO) phase modulation for fast measurement without mechanical delay movement. After describing the degradation effects of detection signal by the optical laser noise and parasitic amplitude modulation, we propose the push-pull EO phase modulation with optical delay control for dynamic range enhancement. Using wideband unitraveling-carrier photodiode and InGaAs photoconductive antenna, spectroscopy up to a 1.5-THz frequency range and imaging are demonstrated.
24 citations
Patent•
23 Feb 2006TL;DR: In this article, a data reproducing unit reproduces an image on a display based on high dynamic range image data acquired from an object and stored in memory, and a dynamic range control unit that controls the dynamic range of the image to be reproduced on the display using one of different types of dynamic ranges control schemes in accordance with one of the display modes.
Abstract: An image reproducing apparatus is operative in accordance with multiple display modes. The image reproducing apparatus includes a data reproducing unit that reproduces an image on a display based on high dynamic range image data acquired from an object and stored in memory, and a dynamic range control unit that controls the dynamic range of the image to be reproduced on the display using one of different types of dynamic range control schemes in accordance with one of the display modes.
24 citations