This paper presents the analysis of possible methods of a terrestrial laser scanning (TLS) data registration using 2d/3ddetectors anddescriptors. The developed approach, where point clouds are processed in form of p...
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This paper presents the analysis of possible methods of a terrestrial laser scanning (TLS) data registration using 2d/3ddetectors anddescriptors. The developed approach, where point clouds are processed in form of panoramic images, orthoimages and3ddata, was described. The accuracy of the registration process was preliminary verified. The two approaches were analysed and compared: the 2d SIFT (Scale-Invariant Feature Transform) detector anddescriptor with the rasterized TLS data and the 3d SIFT detector with the 3d FPFH (Fast Point Feature Histograms) descriptor. The feature points were found and preliminary matched using the OpenCV and PCL (Point Cloud Library) libraries. In order to find the best point cloud representation for the registration process, both the percentage anddistribution of the correctly detected and matched points were analysed. The materials consisted of the point clouds of two chambers from the Museum of King John III's Palace in Wilanow. They were acquired using the Z+F 5006h and 5003 TLS scanners. The performed analysis showed that the lowest RMSE values were for the 2ddetectors and orthoimages. However, in the case of the point number anddistribution, better results were obtained for using the 3ddetector.
The objective of this work was to evaluate the efficiency of bidimensional array detectors (MatriXX (R) and QA BeamChecker Plus (R)) and a tridimensional array detector (ArcCHECK (R)) in the commissioning of dynamic w...
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The objective of this work was to evaluate the efficiency of bidimensional array detectors (MatriXX (R) and QA BeamChecker Plus (R)) and a tridimensional array detector (ArcCHECK (R)) in the commissioning of dynamic wedge filters of clinical linear accelerators in order to discuss the convenience and limitation of these devices for such use. The efficiency of MatriXX was investigated in symmetry tests of the collimator jaws, dose linearity, dose rate, filter factor, dose profiles at different depths for 30 degrees, 45 degrees, and 60 degrees dynamic wedge filters, anddose distribution. The efficiency of ArcCHECK was verified in a test of the influence of the gravitational force on the collimator simulating wedges filters. With QA BeamChecker Plus, the 6 MV megavoltage photon beam output constancy was analyzed. In all tests, the three detectors presented good results, indicating that this set of detectors is suitable for the commissioning of dynamic wedge filters.
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