MTF measurement methods for imaging devices usually require the use of an optical system to project the image of the object onto the detector. So, MTF results quality strongly depends on the accuracy of the optical adjustments (alignments, focusing...). Dedicated edge patterns have been implemented at the chip level on a CMOS imager. One of them emulates the target used in the ISO 12233 slanted...

Abstract--In this work, a unified model, based on a thorough analysis of experimental data, is developed for the overall Modulation Transfer Function (MTF) estimation for CMOS image sensors. The model covers the physical diffusion effect together with the influence of the pixel active area geometrical shape. Comparison of both, our predicted results and the MTF calculated from the Point Spread ...

This study aims to investigate the potential use of LaBr3:Ce and LaCl3:Ce materials in SPECT imaging. GATE Monte Carlo simulations of single-head gamma camera and a Tc point source were performed to evaluate the energy spectra, modulation transfer function (MTF) and detection efficiency. A range of Ce concentrations (0.5, 5, 10 and 15)% of LaBr3:Ce and LaCl3:Ce crystals was simulated in conjunc...

Sampling modulation transfer function (MTF) as defined in Park et al. [Appl. Opt. 23, 2527-2582 (1984)] as an x and y sampling can be generalized for image data not along x and y directions. For a given sampling lattice (such as in a laser printer, a scene projector, or a focal-plane array), we construct a two-dimensional sampling MTF based on the distance between nearest samples in each direct...

PURPOSE To examine the temporal changes in the modulation transfer function (MTF) of the eye after a blink. METHODS The distance MTF of a 5-mm pupil was derived from double-pass retinal images in 20 healthy young subjects at various intervals after a blink (1 second up to 15 seconds). Such measurements include the effects of wavefront aberration, scattered light, and errors in focus and are t...

There has been an increasing use of hormonal therapy among male-to-female (MtF) transgender individuals. This long-term hormone replacement therapy (HRT) renders MtF individuals a unique patient subgroup in terms of breast cancer risk. This case describes a MtF transgender who presented with a breast lesion concerning for malignancy following hormonal replacement therapy. The patient additional...

An imaging sensor’s spatial quality can be expressed by the system’s point spread function (PSF). The PSF of a pushbroom Charge-Coupled Device (CCD) satellite sensor was numerically modeled including contributions from optic, detector, sensor motion, and electronic components. Synthetic edge and pulse targets with various intensity levels were developed and then convolved with the generic senso...

Experiments have shown that the quality of printed images depends on the capacity of the printing system to accurately reproduce details. We propose to improve the quality by compensating for the Modulation Transfer Function (MTF) of the printing system. The MTF of the printing system is measured using a modified version of the method proposed by Jang and Allebach [1]. Then the MTF is adaptivel...

A generalized exponential spectrum model is derived, which considers finite turbulence inner and outer scales and has a general spectral power law value between the range 3 to 5 instead of standard power law value 11/3. Based on this generalized spectrum model, a new generalized long exposure turbulence modulation transfer function (MTF) is obtained for optical plane and spherical wave propagat...

All organisms are confronted with external variations in trace element abundance. To elucidate the mechanisms that maintain metal homeostasis and protect against heavy metal stress, we have determined the transcriptome responses in Drosophila to sublethal doses of cadmium, zinc, copper, as well as to copper depletion. Furthermore, we analyzed the transcriptome of a metal-responsive transcriptio...