This paper presents an automatic system for the detection of buildings from LIDAR data and multispectral imagery, which employs a threshold-free evaluation system that does not involve any thresholds based on human choice. Two binary masks are obtained from the LIDAR data: a ‘primary building mask’ and a ‘secondary building mask’. Line segments are extracted from around the primary building mas...

Processing noisy signals using the ideal binary mask has been shown to improve automatic speech recognition (ASR) performance. In this paper, we present the first study that investigates the role of mask patterns in ASR under varying signalto-noise ratios (SNR), noise conditions and mask definitions. Binary masks are typically computed either by comparing the local SNR within a time-frequency u...

We have investigated the spatial transfer characteristics of the mechanisms sensitive to color in the human visual system using a method of simultaneous spatial masking with isoluminant chromatic stimuli. The test stimuli were Gaussian enveloped red-green gratings of three spatial frequencies in the lowpass region of the color domain (0.25, 0.5 and 1 c/deg). The masking stimuli were red-green g...

OBJECTIVE The intention of this manikin-based trial was to evaluate whether laypersons are able to operate an I-gel laryngeal mask (I-gel) modified for mouth-to-mask ventilation after receiving brief on-site instruction. SETTING Entrance hall of a university hospital and the city campus of a public technical university, using a protected manikin scenario. METHODS Laypersons were handed a la...

We describe an Er3+-doped aluminosilicate core photonic crystal fibre laser incorporating distributed Bragg reflectors written by two-photon 193nm irradiation through an optical phase mask as the feedback elements. The laser is diode pumped at 980nm and evidence of dual linewidth laser operation close to threshold is observed. However, at higher pumping levels gain competition preferentially se...

Foley [J. Opt. Soc. Am. A 11 (1994) 1710] has proposed an influential psychophysical model of masking in which mask components in a contrast gain pool are raised to an exponent before summation and divisive inhibition. We tested this summation rule in experiments in which contrast detection thresholds were measured for a vertical 1 c/deg (or 2 c/deg) sine-wave component in the presence of a 3 c...

A new multiple biometrics based encryption technique using digital holographic security system has been proposed. In this method, a face image of an enrolled person can be spatially multiplexed by a phase mask. This phase mask has been generated by the fingerprint of the enrolled person. In order to overcome the problem of rotation and scaling of the fingerprint, the log polar transform of the ...

Introduction: The aim of this study was to determine the accuracy of two different immobilization methods in patient positioning in cranial radiotherapy. The six-dimensional (6D) target localization accuracy of using a dedicated stereotactic mask was compared with that of a conventional head mask by the ExacTrac system. Material and Methods: ...

To decouple interocular suppression and binocular summation we varied the relative phase of mask and target in a 2IFC contrast-masking paradigm. In Experiment I, dichoptic mask gratings had the same orientation and spatial frequency as the target. For in-phase masking, suppression was strong (a log-log slope of approximately 1) and there was weak facilitation at low mask contrasts. Anti-phase m...