Two sets of photographs were used for creation of images presented on this page. The first set consists of color slides and it was taken in Chile by Vojtech Rušin. The inner corona is very well recorded on these slides but only up to the distance of about 0.7 solar radii. The outer part of corona was fortunately well recorded by Úpice observatory expedition led by Eva Marková. They took set of B&W images which I used to improve contrast in the distant part of corona. The most critical step of processing was precise alignment of images with different scale and orientation. These alignment was done by means of phase correlation technique based on Fourier transform. The time delay between the sets of images was rather long - about 23 minutes but in the outer part of corona there were no features which could to be supposed fast moving. Therefore the composition of both sets of images didn't cause resulting image blurring.

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Miloslav Druckmüller
Institute of Mathematics, Faculty of Mechanical Engineering
Brno University of Technology, Czech Republic
Page last update: 5.6.2007