Aims: To compare central corneal thickness measurements of three pachymetry devices in eyes after laser in situ keratomileusis (LASIK). Methods: Central corneal thickness was measured in 203 eyes after myopic LASIK. Orbscan II scanning slit topography (Bausch & Lomb), SP-2000P non-contact specular microscopy (Topcon), and ultrasonic pachymetry (Tomey) were used in this sequence. Results: Three ...

The problem of accurate depth estimation using stereo in the presence of specular reection is addressed. Specular re ection is viewpoint dependent and can cause large intensity di erences at corresponding points. Hence, mismatches can result causing signi cant depth errors. Current stereo algorithms largely ignore specular re ection which is a fundamental re ection phenomenon from surfaces, bot...

Different industries are usually faced with computer color matching as an important problem. The most famous formula which is commonly used for recipe prediction is based on Kubelka-Munk K-M theory. Considering that spectrophotometer’s geometry and its situation influence the measured spectral values, the performance of this method can be affected by the instrument. In the present study, three ...

All existing shape extraction techniques that are based on photometric measurements rely on assumed surface reflection properties. We propose a method for determining the shape of surfaces whose reflectance properties may vary from Lambertian to specular without prior knowledge of the relative strengths of the Lambertian and specular components of reflection. The object surface is illuminated u...

Specular reflections present difficulties for many areas of computer vision such as stereo and segmentation. To separate specular and diffuse reflection components, previous approaches generally require accurate segmentation, regionally uniform reflectance or structured lighting. To overcome these limiting assumptions, we propose a method based on color analysis and multibaseline stereo that si...

This article proposes several colour points tracking methods which are robust to illumination changes. Firstly, the illumination correction is achieved by computing simultaneously a local photometric model and a motion model during the image sequence. Secondly, some colour invariants are used to compensate in each point for the illumination changes. Then, since most of these attributes are not ...

Stephan et al. (Stephan, K. et al. [2010]. Geophys. Res. Lett. 37, 7104–+.) first saw the glint of sunlight specularly reflected off of Titan’s lakes. We develop a quantitative model for analyzing the photometric lightcurve generated during a flyby in which the specularly reflected light flux depends on the fraction of the solar specular footprint that is covered by liquid. We allow for surface...

Many materials, including leaves, water, plastic, and chrome exhibit specular reflections. It seems reasonable that the visual system can somehow exploit specular reflections to recover three-dimensional (3D) shape. Previous studies (e.g., J. T. Todd & E. Mingolla, 1983; J. F. Norman, J. T. Todd, & G. A. Orban, 2004) have shown that specular reflections aid shape estimation, but the relevant im...

This paper presents a moiré-based technique for measuring the threedimensional shapes of specular surfaces. In it, a Ronchi grating is closely located before the measured object and illuminated by diffusive light sources. When we observe the measured object through this grating, moiré fringes are generated by the superposition of this grating and its virtual image produced by the measured specu...

A key challenge facing computer vision systems is the presence of highly specular surfaces. Such surfaces present a challenge to conventional vision systems due to their reflective nature, which can mask the true structure of the surface and lead to incorrect measurements when traditional computer vision algorithms are used. Here we present a novel approach to reconstructing the local surface s...