Astron. Astrophys. Suppl. Ser. 147, 1-4
How to determine the quality of solar granulation images:
The optimal window method
C. Giammanco 1,2
1 - Università degli studi di Roma Tor Vergata, Roma, Italy
2 - Instituto de Astrofísica de Canarias, Via Lactea, E-38200 La
Laguna, Tenerife, Spain
Received January 21; accepted June 9, 2000
An optimal window for image analysis is determined by means of information theory.
The size of the window is then used as a good estimator of image quality. The method is sensitive to the size of the
structures present in the image (contrary to the contrast method, widely used to select the best images of a series) and
can provide a quality map, indicating the zones more or less degraded in the image.
In this letter I describe the optimal window method (OWM)
and compare it with the contrast method, showing a first
application to a series of images taken at Themis IPM.
Key words: the Sun: granulation -- methods: data analysis
Copyright The European Southern Observatory (ESO)