Measurement of the modulation transfer function of infrared cameras

Tzannes, Alexis P.; Mooney, Jonathan Martin

doi:10.1117/12.203133

Cited by 108 publications

(23 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…11 We found it useful to use a tilted knife-edge to construct a superresolution representation of the edge, from which the MTF can be calculated out to the full detector sampling frequency, or even beyond. 2,3,9,12 Additional limitations of MTF measurements for digital imaging systems can arise from phase errors and detector noise. The technique described here uses apodization to reduce errors from detector noise and phase correction techniques that enable the MTF to decay to zero.…”

Section: Sampling Considerations For the Mtf Of Digitalmentioning

confidence: 99%

See 1 more Smart Citation

Measuring the modulation transfer function of an imaging spectrometer with rooflines of opportunity

et al. 2010

View full text Add to dashboard Cite

Measuring the modulation transfer function (MTF) of digital imagers focused at or near infinity in laboratory or field settings presents difficulties because the optical path is longer than a typical laboratory. Also, digital imagers can be hindered by low-resolution detectors, resulting in the resolution of the optics surpassing that of the detector. We measure the MTF for a short-wave infrared hyperspectral imager developed by Resonon, Inc., of Bozeman, Montana, which exhibits both characteristics. These difficulties are overcome with a technique that uses images of building rooflines in an oversampled, tilted knife-edge-based MTF measurement. The dark rooftops backlit by a uniformly cloudy sky provide the high-contrast edges required to perform knife-edge MTF measurements. The MTF response is measured at five wavelengths across the imager's spectral band: 1085, 1178, 1292, 1548, and 1629 nm. The MTF also is observed at various distances from the roof to investigate performance change with distance. Optimum imaging is observed at a distance of 150 m, potentially a result of imperfect infinity focus and atmospheric turbulence. In a laboratory validation of the MTF algorithm using a monochrome visible imager, the roofline MTF results are similar to results from point-source and sine-card MTF measurements. C 2010 Society of Photo-Optical Instrumentation Engineers.

show abstract

Section: Sampling Considerations For the Mtf Of Digitalmentioning

confidence: 99%

“…Methods to measure the MTF of digital imaging systems include knife-edge techniques, 1-3 random noise targets, 4, 5 point sources, 6 sine waves, or other test targets. 1,3 In this paper the knife-edge MTF technique was selected to characterize a short-wave infrared (SWIR) hyperspectral imager.…”

Section: Introductionmentioning

confidence: 99%

Measuring the modulation transfer function of an imaging spectrometer with rooflines of opportunity

et al. 2010

View full text Add to dashboard Cite

show abstract

“…The modulation transfer function (MTF) is the module of the Fourier transform of PSF, so MTF can be used to evaluate and optimize an optical system too. The knife-edge method [12] can measure MTF accurately. Thus, knife-edge images under different conditions are obtained by the physical experimental platform.…”

Section: Methodsmentioning

confidence: 99%

“…The focus position is the point that makes M(I) maximum. At last, we use the method [12] to get MTFs under different conditions. In order to improve the test accuracy and reduce the influence of noise, 100 images are averaged to improve the signal noise ratio.…”

Section: Methodsmentioning

confidence: 99%

Calculating model for equivalent thermal defocus amount in infrared imaging system

Zhang

Shi

et al. 2016

Infrared Physics & Technology

View full text Add to dashboard Cite

“…To estimate the image resolution of the contrast target embedded in different anisotropic scattering media, we obtained a line spread function ͑LSF͒ using a modified knife-edge method. 9 Using this method, we estimated the image resolution from the LSF calculated from a skewed edge on the contrast target and we used the full width at half maximum ͑FWHM͒ of the LSF as our image resolution of the contrast target. From the images that we analyzed for the contrast improvement, the image resolutions of the target embedded in the surrounding scattering medium of =2 to 3 were 6 to 8 pixels ͑pixel size= 13 m͒, and our back-directional gating angles ͑ ഛ ϳ 6 deg͒ played a minimal role on the image resolution of the embedded target.…”

mentioning

confidence: 99%

Diffuse light suppression of back-directional gating imaging in high anisotropic media

Liu

Kim

2009

J. Biomed. Opt.

View full text Add to dashboard Cite

Abstract. We experimentally demonstrate that backdirectional gating in an imaging setup can potentially remove unwanted diffuse light to improve the contrast of an object embedded in a high anisotropic surrounding medium. In such back-directional gating, the high anisotropic property of the surrounding medium can serve as a waveguide to deliver the incident light to the embedded object and to isolate the ballistic or snake-like light backscattered from the object in a moderate depth. We further discuss the effects of back-directional gating in the image formation in terms of the image resolution and the depth of field. Although backscattering detections of biological tissue have recently received considerable attention, we, for the first time to our knowledge, show its potential advantage for the contrast improvement in high anisotropic media.

show abstract

Measurement of the modulation transfer function of infrared cameras

Cited by 108 publications

References 1 publication

Measuring the modulation transfer function of an imaging spectrometer with rooflines of opportunity

Measuring the modulation transfer function of an imaging spectrometer with rooflines of opportunity

Calculating model for equivalent thermal defocus amount in infrared imaging system

Diffuse light suppression of back-directional gating imaging in high anisotropic media

Contact Info

Product

Resources

About