AN INTEGRATED LINEAR TECHNIQUE FOR POSE ESTIMATION FROM DIFFERENT GEOMETRIC FEATURES

Author(s):  
QIANG JI ◽  
MAURO S. COSTA ◽  
ROBERT M. HARALICK ◽  
LINDA G. SHAPIRO

Existing linear solutions for the pose estimation (or exterior orientation) problem suffer from a lack of robustness and accuracy partially due to the fact that the majority of the methods utilize only one type of geometric entity and their frameworks do not allow simultaneous use of different types of features. Furthermore, the orthonormality constraints are weakly enforced or not enforced at all. We have developed a new analytic linear least-squares framework for determining pose from multiple types of geometric features. The technique utilizes correspondences between points, between lines and between ellipse–circle pairs. The redundancy provided by different geometric features improves the robustness and accuracy of the least-squares solution. A novel way of approximately imposing orthonormality constraints on the sought rotation matrix within the linear framework is presented. Results from experimental evaluation of the new technique using both synthetic data and real images reveal its improved robustness and accuracy over existing direct methods.

1978 ◽  
Vol 56 (16) ◽  
pp. 2150-2155 ◽  
Author(s):  
John W. ApSimon ◽  
Satyanand Badripersaud ◽  
Michael L. Post ◽  
Eric J. Gabe

The reaction of 2-keto-1β,4aβ-dimethyl-1α-[2-(3-keto-1,4,4-trimethylcyclohexyl)ethyl]-7-methoxy-1,2,3,4,4a,9-hexahydrophenanthrene 1a and b with p-toluenesulphonic acid in boiling xylene yields the rearranged product, 1,10-dimethyl-2-[2-(3-keto-1,4,4-trimethylcyclohexyl)-ethyl]-7-methoxy-3,4-dihydroanthracene (3). Crystals of 3 are monoclinic, space group P21/c, Z = 4, with a = 7.2684(3), b = 30.942(2), c = 10.5544(7) Å, β = 98.24(1)°. The structure was determined by direct methods from diffractometer data and refined by block-diagonal least-squares to an R of 0.043 for 1810 observed reflections. The molecule exhibits no unusual geometric features, although positional disorder is apparent in the cyclohexanone moiety.A possible route for the formation of 3 from 1a and b is presented.


Author(s):  
Nived Chebrolu ◽  
Thomas Labe ◽  
Olga Vysotska ◽  
Jens Behley ◽  
Cyrill Stachniss

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