Results 251 to 260 of about 1,342,457 (294)

Reducing Illumination Based on Nonlinear Gamma Correction

2007 IEEE International Conference on Image Processing, 2007
Illumination always affects image quality seriously in practice. To weaken illumination effect on image quality, this paper proposes an adaptive gamma correction method. First, a mapping between pixel and gamma values is built. The gamma values are then revised using two non-linear functions to prevent image distortion. Experimental results demonstrate
Yihua Shi, Jinfeng Yang, Renbiao Wu
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Pitfalls in field uniformity corrections for a gamma camera

The British Journal of Radiology, 1983
In the past few years, microprocessors have been introduced for field uniformity in gamma cameras and these require storage of a reference flood image. Frequently, a commercially available thin plastic disc containing 57Co is used. The assumption that this correction is valid for the photon energies used in clinical studies must be confirmed for each ...
J M, Franquiz, R R, Fraxedas
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Adjustable Gamma Correction Circuit for TFT LCD

2005 IEEE International Symposium on Circuits and Systems, 2005
Gamma correction is an essential function in every display device such as CRT, plasma TV, and TFT LCD. In this paper, a new gamma correction architecture of the source drive IC used in the TFT LCD is proposed. Instead of using non-linear DAC architecture, a linear DAC architecture is used to reduce the number of resistors required.
Hung-Yi Chen
exaly   +3 more sources

Gamma and Gamma Correction in Television Production

2009
Gamma characteristic of Catode Ray Tube is explained. New Liquid Cristal Displays and Plasma Displays have different gamma characteristic and that has impact on achieving overall linear or near linear transfer characteristic. Gamma correction in cameras has it’ s traditional role but new meanings are receantly introduced.
Jurić, Sanja, Klepac, Vedran
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Attenuation Correction in Gamma Emission Computed Tomography

Journal of Computer Assisted Tomography, 1981
A method of computing tomographic images from single photon radionuclide emission data is presented. The method takes into account attenuation of gamma rays inside the source and makes use of an iterative technique, based on the difference between the projection data obtained from the source and computed projections, called reprojections, from ...
T E, Walters, W, Simon, D A, Chesler, J A, Correia   +3 more
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Analog implementation of gamma-correction for CMOS cameras

1998 IEEE International Conference on Electronics, Circuits and Systems. Surfing the Waves of Science and Technology (Cat. No.98EX196), 2002
In this paper an analog synthesizer of nonlinear functions is applied to integrated color processing in CMOS cameras. For reproducing images on a display with desired contrast and color correction, a nonlinear distortion of the signal associated with pixels of different colors is needed. The adoption of a design flow for the implementation of nonlinear
Riccardo Rovatti, Eleonora Franchi, Nicolò Manaresi, Alberto Bellini, Marco Tartagni   +4 more
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An Image Enhancement Method Based on Gamma Correction

2009 Second International Symposium on Computational Intelligence and Design, 2009
The research of the wheel alignment system based on computer vision is a popular field for automobile safety. For realizing the effective and accurate feature recognition for the chessboard calibration target of the system, the enhancement algorithms based on Gamma correction are indicated.
Guan Xu, Jian Su, Hongda Pan, Zhiguo Zhang, Haibin Gong   +4 more
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Gamma correction for digital fringe projection profilometry

Applied Optics, 2004
Digital fringe projection profilometry utilizes a digital video projector as a structured light source and thus gains great flexibility. However, the gamma nonlinearity of the video projector inevitably decreases the accuracy and resolution of the measurement.
Hongwei, Guo, Haitao, He, Mingyi, Chen
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Forensic estimation of gamma correction in digital images

2010 IEEE International Conference on Image Processing, 2010
In the digital era, digital photographs become pervasive and are frequently used to record event facts. Authenticity and integrity of such photos can be ascertained by discovering more information about the previously applied operations. In this paper, we propose a forensic scheme for identifying and reconstructing gamma correction operations in ...
Gang Cao 0001, Yao Zhao 0001, Rongrong Ni   +2 more
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A chemical correction factor in gamma-gamma density logging

Journal of Geophysical Research, 1960
Log-derived rock densities may be in error for two reasons: first, the ratio of A/Z varies for different chemical elements; second, the photoelectric absorption, neglected in calibration, may become appreciable if heavier elements are present. The effects are discussed and the A/Z correction factors calculated. (auth)
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