1,720,997 research outputs found
3D vision based on the combination of Gray Code and Phase Shift light projection: analysis and compensation of the systematic errors
No full textA combination of phase-shift with gray-code light projection into a three-dimensional vision system based on the projection of structured light is presented. The gray-code method is exploited to detect without ambiguity even marked surface discontinuities, whereas the phase-shift technique allows the measurement of fine surface details. The system shows excellent linearity. An overall mean value of the measurement error equal to 40 μm, with a variability of approximately ±35 μm, corresponding to 0.06% of full scale, has been estimated. The implementation of the technique is discussed, the analysis of the systematic errors is presented in detail, and the calibration procedure designed to determine the optimal setting of the measurement parameters is illustrate
Fast acquisition of point clouds by means of a 3D optical sensor based on active stereo vision
No full text3D shape recovery and registration based on the projection of non-coherent structured light
No full textFast digitization of heritage objects by means of a 3D vision system based on the projection of structured light
No full textCalibration and performance evaluation of a 3-D imaging sensor based on the projection of structured light
No full textIn this paper, the procedure developed to calibrate a whole-field optical profilometer and the evaluation of the measurement performance of the system are presented. The sensor is based on the projection of structured light and on active triangulation. The dependence of the measurements on the geometric parameters of the system is shown, as well as the criterion to calibrate the system. From the extensive set of experiments carried out to evaluate the measurement performance, good linearity has been observed, and an overall mean value of the measurement error equal to 40 μm, with a variability of about ±35 μm has been estimated
Nodular extramedullary hematopoiesis involving the adrenal gland. An uncommon cause of adrenal "incidentaloma".
No full textThree dimensional Imaging based on Gray Code projection: Characterization of the the measuring algorithm and development of a measuring system for industrial applications
No full textA three-dimensional (3-D) imaging system based on Gray-code projection is described; it is thought to be used as an integration to the already developed profilometer based on the projection of multifrequency gratings. The Gray-code method allows us to evaluate the 3-D profile of objects that present even marked discontinuities of the surface, thus increasing the flexibility of the measuring system as to the topology of the objects that can be measured. The basic aspects of Gray-code projection for 3-D imaging and profiling are discussed, with particular emphasis devoted to the study of the resolution of the method and to the analysis of the systematic errors. The results of this study allow us to determine the optimal setting of the parameters of the measurement and to develop a suitable calibration procedure. The procedures for implementing the Gray-code method are presented, and some interesting experimental results are reported. Calibration of the system reveals an accuracy of 0.2 mm, corresponding to 0.1% of the field of view
A 3D imaging system for industrial applications with improved flexibility and robustness
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