Learn More
We introduce a three-dimensional sensor designed primarily for rough objects that supplies an accuracy that is limited only by the roughness of the object surface. This differs from conventional optical systems in which the depth accuracy is limited by the aperture. Consequently, our sensor supplies high accuracy with a small aperture, i.e., we can probe(More)
OBJECTIVE To assess measurement errors of a novel technique for the three-dimensional determination of the degree of facial symmetry in patients suffering from unilateral cleft lip and palate malformations. DESIGN Technical report, reliability study. SETTING Cleft Lip and Palate Center of the University of Erlangen-Nuremberg, Erlangen, Germany. (More)
In this paper we present an application of optical metrology and image processing to oral and max-illofacial surgery. Our goal is to support the surgeon intraoperatively during the repair of a displacement of the globe of the eye. To date, the surgeon has to evaluate his operation result solely by visual judgement. Our idea is to provide the surgeon(More)
AIM To assess the degree of facial symmetry in patients suffering from unilateral cleft lip, alveolus and palate (UCLAP) by determining differences between the cleft and the non-cleft hemifaces from 3D surface data. PATIENTS AND METHODS In twenty-two 10-year-old UCLAP patients, who had the lip repaired using the Tennison-Randall technique and did not(More)
The purpose of this study was to validate the assessment of visible volume changes of the facial soft tissue with an optical three-dimensional sensor and to introduce new parameters for the evaluation of the soft-tissue shape achieved from three-dimensional data of selected cases of midfacial distraction. Images of a truncated cone of known volume were(More)
We present a new method to measure specular free-form surfaces within seconds. We call the measuring principle 'Phase Measuring Deflectometry' (PMD). With a stereo based enhancement of PMD we are able to measure both the height and the slope of the surface. The basic principle is to project sinusoidal fringe patterns onto a screen located remotely from the(More)
We report a method for 3-D sensing by light sectioning. The specific goal is to demonstrate that high resolution and large depth can be achieved simultaneously, thus overcoming the major limitation of conventional light sectioning. We use the diffraction pattern of an axicon to generate a light knife with large depth of field (for example, 1700 mm) and high(More)
We discuss the uncertainty limit in distance sensing by laser triangulation. The uncertainty in distance measurement of laser triangulation sensors and other coherent sensors is limited by speckle noise. Speckle arises because of the coherent illumination in combination with rough surfaces. A minimum limit on the distance uncertainty is derived through(More)
OBJECTIVE The objective of this study was to analyze the reliability of a landmark-independent method for determining the facial symmetry plane and degree of asymmetry based on three-dimensional data from the facial surface from two sets of recordings, one performed consecutively and one performed on different days. MATERIALS AND METHODS We used an(More)