Results 211 to 220 of about 215,562 (263)

Interpreting multifocal intraocular lens modulation transfer functions

Journal of Cataract and Refractive Surgery, 1993
The optical performance of new multifocal intraocular lens designs is frequently assessed using the modulation transfer function (MTF). We discuss the relationship between the MTF and clinical measures of human visual function, such as threshold visual acuity and contrast sensitivity.
A, Lang, V, Portney
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Aerosol Modulation Transfer Function

2017
As described in the previous two chapters, turbulence gives rise to image degradation as a result of wavefront tilt as well as random image detail displacement deriving from random changes in refractive index of the propagation channel. Because of the randomness, a statistical rather than deterministic approach characterizes turbulence.
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Modulation thresholds and temporal modulation transfer functions

The Journal of the Acoustical Society of America, 1976
Temporal Modulation Transfer Functions (TMTF's) were obtained by measuring the threshold amplitude of sinusoidal modulation as a function of modulating frequency. For modulation frequencies below approximately 800 Hz, TMTF's obtained with a continuous wide-band noise carrier generally show the low-pass characteristic reported previously [J. Acoust. Soc.
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Modulation transfer function measurements of microjetted microlenses

Applied Optics, 1999
We measured the modulation transfer function for microjetted microlenses with diameters ranging between 109 and 400 microm and with focal lengths ranging between 135 and 540 microm. We found that single-drop 109-microm-diameter microlenses perform close to their theoretical cutoff frequency. However, the larger lenses made with multiple droplets have a
B T, Teipen, D L, MacFarlane
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Turbulence Modulation Transfer Function

2017
There are basically two techniques used to correct for turbulence degradation. One is adaptive optics, whose purpose is to prevent turbulence-derived distortions from being recorded in the image. The other technique is image restoration using typically digital computers. In the latter case, turbulence-derived blur has already been recorded in the image
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Streak Tube Modulation Transfer Functions

SPIE Proceedings, 1990
An exponential model is proposed for streak tube MTFs (modulation transfer functions) based on line spread function measurements. This model is used to derive performance characteristics such as temporal resolution, channel width and pixel size. These results are compared with those predicted by a Gaussian model for the MTF.
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The modulation transfer function in impedance imaging

Clinical Physics and Physiological Measurement, 1992
The concepts of the point spread function (PSF) and its Fourier transform, the modulation transfer function (MTF) are introduced to evaluate an impedance imaging system. The effects of some practical factors which should be taken into account in calculating the MTF are analysed.
J P, Morucci, Y, Shi, B, Rigaud
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Modulation transfer function of charge-coupled devices

Applied Optics, 1990
A method for calculating the modulation transfer function (MTF) of charge-coupled devices (CCD) is presented. The analysis accommodates both the time- and space-variant properties of CCDs as well as input images moving with constant velocity within a scan interval.
J C, Feltz, M A, Karim
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Modulation transfer function of water

OCEAN 75 Conference, 1975
Particulate matter of the sizes, concentrations, and refractive indices found in situ renders the Optical Transfer Function of water a real quantity. Modulation Transfer Function (MTF) is measured in vitro by spatial filtering of the projected image of a slit in the Fourier Transform plane.
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Modulation Transfer Functions

Journal of Speech, Language, and Hearing Research, 1990
Modulation transfer functions (MTFs) were measured with three different psychoacoustical paradigms in the same normal-hearing subjects. In the temporal-probe method, the threshold of a 4-ms probe tone (frequencies of 1000 and 4000 Hz) was measured at various envelope phases within a 100% sinusoidally amplitude-modulated (SAM) noise at modulation ...
D M, Scott, L E, Humes
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