Astron. Astrophys. Suppl. Ser.
Volume 127, Number 3, February I 1998
|Page(s)||587 - 595|
|Published online||15 February 1998|
Discrimination of point-like objects in astronomical images using surface curvature
Laboratoire d'Astronomie Spatiale du CNRS, BP. 8, F-13376 Marseille Cedex 12, France
Send offprint request to: A. Llebaria
Accepted: 4 June 1997
We present a method for the discrimination of point-like objects in astronomical images using surface curvature. The principal curvatures k1 and k2 are calculated using a local quadric approximation to the log of the intensity of the original image. The analysis of the diagram allows to easily separate various shapes and to establish a criterion for discrimination. A mask is then generated and the invalid pixels are replaced by a local, pyramidal interpolation using a non-linear, multiresolution method. We present two applications, the discrimination and removal of stars from the dust tail of comet P/Halley observed while it was crossing the Milky Way, and the removal of cosmic ray impacts from images of the solar corona obtained with a space-coronagraph.
Key words: techniques: image processing / comets: general; P/Halley / sun: corona
© European Southern Observatory (ESO), 1998