The slant of a stereoscopically defined surface cannot be determined solely from horizontal disparities or from derived quantities such as horizontal size ratio (HSR). There are four other signals that, in combination with horizontal disparity, could in principle allow an unambiguous estimate of slant: the vergence and version of the eyes, the vertical size ratio (VSR), and the horizontal gradi...

The contribution of slant and tilt to the detection of differences in local surface orientation was examined for structure-from-motion (SFM) displays of a complex sinusoidal surface. Observers judged whether an elliptical SFM gauge figure appeared to be lying on the surface or intersecting it. The gauge figure orientation either matched the local surface orientation or differed from it in slant...

We have investigated the role of geographical slant in simple navigation and spatial memory tasks, using a computer graphics town called \Hexatown" (Gillner & Mallot 1998). This environment was a hexagonal grid of streets with landmarks placed in each angle between two streets. The whole environment could be slanted by an angle of 4 . Three slant conditions were used: at: no slant; slanted NW: ...

We measured perceived depth from the optic flow (a) when showing a stationary physical or virtual object to observers who moved their head at a normal or slower speed, and (b) when simulating the same optic flow on a computer and presenting it to stationary observers. Our results show that perceived surface slant is systematically distorted, for both the active and the passive viewing of physic...

Many people’s handwriting exhibits various writing slant. This is one of factors greatly varying human handwriting and thus making it more difficult to recognize. This report describes experiments with slant counteraction. The writing slant is estimated on a per word basis and the way the handwriting data is “seen” by the recognizer is transformed in order to counteract the slant. This leaves t...

In her seminal article in Psychological Review, A. S. Gilinsky (1951) successfully described the relationship between physical distance (D) and perceived distance (d) with the equation d = DA/(A + D), where A = constant. To understand its theoretical underpinning, the authors of the current article capitalized on space perception mechanisms based on the ground surface to derive the distance equ...

Our two eyes receive different views of a visual scene, and the resulting binocular disparities enable us to reconstruct its three-dimensional layout. However, the visual environment is also rich in monocular depth cues. We examined the resulting percept when observers view a scene in which there are large conflicts between the surface slant signaled by binocular disparities and the slant signa...

In this paper, we propose a digital watermarking algorithm based on the Slant transform for the copyright protection of satellite images. Designed to match basis vectors to areas of constant luminance slope, the Slant transform is good for compact energy in “smooth” images. However, our earlier research work suggests that in terms of watermarking, it works better for textured images, for the en...

Four experiments related human perception of depth-order relations in structure-from-motion displays to current Euclidean and affine theories of depth recovery from motion. Discrimination between parallel and nonparallel lines and relative-depth judgments was observed for orthographic projections of rigidly oscillating random-dot surfaces. We found that (1) depth-order relations were perceived ...

This paper presents a method for imaging from the slant plane data collected by a synthetic aperture radar (SAR) over the full rotation or a partial segment of a circular flight path. A Fourier analysis for the Green's function of the imaging system is provided. This analysis is the basis of an inversion for slant plane circular SAR data. The reconstruction algorithm and resolution for this SAR...