Registration and Location Method of Solar Magnetic Field Images Based on Scale-invariant Feature Point Matching

There are differences among different solar observation stations in terms of observation time, scope and equipment. For the convenience of scientific research, it is necessary to work out a way to automatically match and locate the solar images of different observation stations. A method to match and locate solar magnetic field image based on scale-invariant feature point matching is put forward. Firstly, pre-treatment for the original image is carried out by contrast enhancing and down sampling; Secondly, the feature scale-invariant feature points are extracted using scale-invariant feature point detection algorithm; Next, the feature points of the two images are matched and located roughly by seeking their homologous points; Finally, Based on coarse located area, the solar magnetic image can be matched and located exactly. The registration and positioning experiments of the solar magnetic field image in different time periods are carried out, and numbers of matching point pairs, matching logarithm, matching accuracy and matching error are defined to quantitatively analyze the experimental results. As proved by experiment results, the presented method can match and locate the solar magnetic images automatically, accurately and quickly.