6,143 research outputs found
Solving the Pose Ambiguity via a Simple Concentric Circle Constraint
Estimating the pose of objects with circle feature from images is a basic and important question in computer vision community. This paper is focused on the ambiguity problem in pose estimation of circle feature, and a new method is proposed based on the concentric circle constraint. The pose of a single circle feature, in general, can be determined from its projection in the image plane with a pre-calibrated camera. However, there are generally two possible sets of pose parameters. By introducing the concentric circle constraint, interference from the false solution can be excluded. On the basis of element at infinity in projective geometry and the Euclidean distance invariant, cases that concentric circles are coplanar and non-coplanar are discussed respectively. Experiments on these two cases are performed to validate the proposed method
Present and future of the OTELO project
OTELO is an emission-line object survey carried out with the red tunable
filter of the instrument OSIRIS at the GTC, whose aim is to become the deepest
emission-line object survey to date. With 100% of the data of the first
pointing finally obtained in June 2014, we present here some aspects of the
processing of the data and the very first results of the OTELO survey. We also
explain the next steps to be followed in the near future.Comment: Oral contribution presented in the XI Scientific Meeting of the
Spanish Astronomical Society held on September 8-12, in Teruel, Spain (7
pages, 2 figures, 1 table). To appear in Highlights of Spanish Astrophysics
VIII, Proceedings of the XI Scientific Meeting of the Spanish Astronomical
Society. Eds. A. J. Cenarro, F. Figueras, C. Hern\'andez-Monteagudo, J.
Trujillo, L. Valdiviels
Surface brightness measurements for APM galaxies
This paper considers some simple surface brightness (SB) estimates for
galaxies in the Automated Plate Measuring Machine (APM) catalogue in order to
derive homogeneous SB data for a very large sample of faint galaxies. The
isophotal magnitude and area are used to estimate the central surface
brightness and total magnitude based on the assumption of an exponential SB
profile. The surface brightness measurements are corrected for field effects on
each UK Schmidt plate and the zero-point of each plate is adjusted to give a
uniform sample of SB and total magnitude estimates over the whole survey.
Results are obtained for 2.4 million galaxies with blue photographic magnitudes
brighter than b_J = 20.5 covering 4300 deg^2 in the region of the south
galactic cap. Almost all galaxies in our sample have central surface brightness
in the range 20 to 24 b_J mag per arcsec^2. The SB measurements we obtain are
compared to previous SB measurements and we find an acceptable level of error
of +/- 0.2 b_J mag per arcsec^2. The distribution of SB profiles is considered
for different galaxy morphologies for the bright APM galaxies. We find that
early-type galaxies have more centrally concentrated profiles.Comment: 14 pages, 17 figures, accepted for publication in MNRA
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