Size constancy was investigated in DF, a patient with visual form agnosia, using a technique based on Emmert's law of visual after-images. DF was first given a task in which she was asked to indicate the distance of a vertical surface and a task where she had to estimate the width of a series of squares (widths ranging from 5 cm to 35 cm) placed at varying distances and having a constant visual...

This article focuses on algorithms for fast computation of the Euclidean distance between a query point and a subdivision surface. The analyzed algorithms include uniform tessellation approaches, an adaptive evalution technique, and an algorithm using Bézier conversions. These methods are combined with a grid hashing structure for space partitioning to speed up their runtime. The results show t...

We study the performance of distance-three surface code layouts under realistic multi-parameter noise models. We first calculate their thresholds under depolarizing noise. We then compare a Pauli-twirl approximation of amplitude and phase damping to amplitude and phase damping. We find the approximate channel results in a pessimistic estimate of the logical error rate, indicating the realistic ...

The classical morphological segmentation paradigm is based on the watershed transform, constructed by flooding the gradient image seen as a topographic surface. For flooding a topographic surface, a topographic distance is defined from which a minimum distance algorithm is derived for the watershed. In a continuous formulation, this is modeled via the eikonal PDE, which can be solved using curv...

We report on a self-regulating, simple and precise approach to control the distance between a scanning microfluidic probe and a surface. The approach is based on hydrodynamic levitation of the probe over a surface. We demonstrate this distance control in the context of life-sciences, where the surfaces are most often immersed in liquid, and typical variations of the surface topography are in th...

Point sets become an increasingly popular shape representation. Most shape processing and rendering tasks require the approximation of a continuous surface from the point data. We present a surface approximation that is motivated by an efficient iterative ray intersection computation. On each point on a ray, a local normal direction is estimated as the direction of smallest weighted co-variance...

J. Hempel’s definition of the distance of a Heegaard surface generalizes to a complexity for a knot which is in bridge position with respect to a Heegaard surface. Our main result is that the distance of a knot in bridge position is bounded above by twice the genus, plus the number of boundary components, of an essential surface in the knot complement. As a consequence knots constructed via suf...

Nonspecific surface binding of small protein molecules presents a major obstacle to surface biosensing techniques attempting to detect very low concentrations ( 1 pg/mm) of large biological objects such as cells and bacteria. A new method for selective desensitization of a polarimetric waveguide interferometer eliminates the background noise from nonspecific surface binding. We demonstrate the ...

The accurate matching of 3D anatomical surfaces with sensory data such as 2D X-ray projections is a basic problem in Computer and Robot Assisted Surgery. In model-based vision, this problem can be formulated as the estimation of the spatial pose (position and orientation) of a 3D smooth object from 2D video images. We present a new method for determining the rigid body transformation that descr...

Time-of-flight laser radar devices utilizing a single heterostructure semiconductor laser diode as a light source have a measurement spot diameter from a few millimetres to several centimetres depending on the optics and the required optical output power. Inhomogeneities in the reflectivity and surface profile of a target inside the area illuminated by the laser beam can be a source of error in...