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Several authors have measured the detection ability of human observers for objects in correlated (nonwhite) noise. These studies have shown that the human observer has approximately constant efficiency when compared with a nonprewhitening ideal observer. In this paper we add a frequency-selective mechanism to the ideal-observer model, similar to the channel(More)
A minimum-norm least-squares image-reconstruction method for the reconstruction of magnetic resonance images from non-Cartesian sampled data is proposed. The method is based on a general formalism for continuous-to-discrete mapping and pseudoinverse calculation. It does not involve any regridding or interpolation of the data and therefore the methodology(More)
Pixel signal-to-noise ratio is one accepted measure of image quality for predicting observer performance in medical imaging. We have found, however, that images with equal pixel signal-to-noise ratio (SNRp) but different correlation properties give quite different observer-performance measures for a simple detection experiment. The SNR at the output of an(More)
A method for optimizing the aperture size in emission imaging is presented that takes into account limitations due to the Poisson nature of the detected radiation stream as well as the conspicuity limitation imposed by a spatially varying background. System assessment is based on the calculated performance of two model observers: the best linear observer,(More)
We have described previously132 how image reconstruction algorithms can be evaluated on the basis of how well binary-discrimination tasks can be performed using the reconstructions. The test statistic in the detection task was the estimated activity within the object, also known as the non-prewhitening matched-filter output. This approximation to the(More)
gitated vessels are used throughout the chemical engineering industries (CEI) for diverse applications including storing, blending and reacting materials. Agitator design requires specification of the motor, drive and impeller system that will satisfy both process (1, 2, 3) and mechanical (4) requirements. In addition, most agitated vessels are baffled, and(More)
It is well known that image assessment is task dependent. This is demonstrated in the context of images reconstructed from sparse data using MEM-SYS3. We demonstrate that the problem of determining the regularization-or hy-perparameter has a task-dependent character independent of whether the images are viewed by human observers or by classical or(More)
  • K J Myers
  • 1975
Our eyes and their extraocular motility muscles are a marvelously engineered system for external data gathering. On teleological grounds alone, it would appear that ocular versions and rotations take place, in many cases, along geodesics of least energy and that paths of higher energy are only taken for reasons of binocular near vision. This paper examines(More)
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