Accuracy Of Magnification Research Articles

Single-image super-resolution based on local biquadratic spline with edge constraints and adaptive optimization in transform domain

This paper proposes a novel single-image super-resolution method based on local biquadratic spline with edge constraints and adaptive optimization in transform domain. The complex internal structure of the image makes the values of adjacent pixels often differ greatly. Using surface patches to interpolate image blocks can avoid large surface oscillation. Because the quadratic spline has better shape-preserving property, we construct the biquadratic spline surface on each image block to make the interpolation more flexible. The boundary conditions have great influence on the shape of local biquadratic spline surfaces and are the keys to constructing surfaces. Using edge information as a constraint to calculate them can reduce jagged and mosaic effects. To decrease the errors caused by surface fitting, we propose a new adaptive optimization model in transform domain. Compared with the traditional iterative back-projection, this model further improves the magnification accuracy by introducing SVD-based adaptive optimization. In the optimization, we convert similar block matrices to the transform domain by SVD. Then the contraction coefficients are calculated according to the non-local self-similarity, and the singular values are contracted. Experimental comparison with the other state-of-the-art methods shows that the proposed method has better performance in both visual effect and quantitative measurement.

THE SYSTEMATICS OF STRONG LENS MODELING QUANTIFIED: THE EFFECTS OF CONSTRAINT SELECTION AND REDSHIFT INFORMATION ON MAGNIFICATION, MASS, AND MULTIPLE IMAGE PREDICTABILITY

ABSTRACT Until now, systematic errors in strong gravitational lens modeling have been acknowledged but have never been fully quantified. Here, we launch an investigation into the systematics induced by constraint selection. We model the simulated cluster Ares 362 times using random selections of image systems with and without spectroscopic redshifts and quantify the systematics using several diagnostics: image predictability, accuracy of model-predicted redshifts, enclosed mass, and magnification. We find that for models with >15 image systems, the image plane rms does not decrease significantly when more systems are added; however, the rms values quoted in the literature may be misleading as to the ability of a model to predict new multiple images. The mass is well constrained near the Einstein radius in all cases, and systematic error drops to <2% for models using >10 image systems. Magnification errors are smallest along the straight portions of the critical curve, and the value of the magnification is systematically lower near curved portions. For >15 systems, the systematic error on magnification is ∼2%. We report no trend in magnification error with the fraction of spectroscopic image systems when selecting constraints at random; however, when using the same selection of constraints, increasing this fraction up to ∼0.5 will increase model accuracy. The results suggest that the selection of constraints, rather than quantity alone, determines the accuracy of the magnification. We note that spectroscopic follow-up of at least a few image systems is crucial because models without any spectroscopic redshifts are inaccurate across all of our diagnostics.

Evaluating gaze-based interface tools to facilitate point-and-select tasks with small targets

Gaze interaction affords hands-free control of computers. Pointing to and selecting small targets using gaze alone is difficult because of the limited accuracy of gaze pointing. This is the first experimental comparison of gaze-based interface tools for small-target (e.g. <12 × 12 pixels) point-and-select tasks. We conducted two experiments comparing the performance of dwell, magnification and zoom methods in point-and-select tasks with small targets in single- and multiple-target layouts. Both magnification and zoom showed higher hit rates than dwell. Hit rates were higher when using magnification than when using zoom, but total pointing times were shorter using zoom. Furthermore, participants perceived magnification as more fatiguing than zoom. The higher accuracy of magnification makes it preferable when interacting with small targets. Our findings may guide the development of interface tools to facilitate access to mainstream interfaces for people with motor disabilities and other users in need of hands-free interaction.

Initial Instrument Evaluation And Performance Monitoring For SEMs

Abstract Microscopes in an electron microscope laboratory are built to be within specific tolerances in relation to resolution and magnification. The final specification from the manufacturer should include detail of magnification accuracy, drift rate, contamination rate and resolution, On delivery, the onus is on the installation engineer to confirm that the microscope meets specification. However, the final responsibility for microscope acceptance to specifications is the responsibility of the lab management.. Energy dispersive instrumentation is also specified as to specific resolution; and should also be confirmed on installation. In some cases, those with final responsibility for equipment performance might not resolve with the manufacturer's representee, at installation, that the instrumentation meets all specifications.

How Accurate is Your SEM’s Magnification?

Abstract With such topics as ISO-9000, TQM (Total Quality Management) and with the Maicolm Baldridge Quality Award being mentioned these days, it may not be long before instrument calibration becomes an issue in your laboratory. Among the many important areas governed will be magnification accuracy of optical microscopes, TEMs, and SEMs, The following brief discussion probes the rather complex subject of SEM magnification accuracy.