Zernike Moments Description of Solar and Astronomical Features: Python Code

Due to the massive increase in astronomical images (such as James Web,Solar Dynamic Observatory, and Solar Orbiter), automatic image description is es-sential for solar and astronomical. Zernike moments (ZMs) are unique due to theorthogonality and completeness of Zernike polynomials (ZPs); hence, ZMs are valu-able for converting a two-dimensional image to a one-dimensional series of complexnumbers. The magnitude of ZMs is rotation invariant, and by applying image nor-malization, scale and translation invariants can be made, which are helpful propertiesfor describing solar and astronomical images. The lower-order ZMs express the overallshape of the objects of an image, and the higher-order ZMs provide more details ofthe objects and delicate structures within an image. In this Python package, availableat GitHub and PyPI, we describe the characteristics of ZMs via several examples ofsolar (large and small scale) features, astronomical, and human face images. Theseindependent and unique properties of ZMs can describe the structure and morphologyof objects in an image. Hence, ZMs are helpful in machine learning to identify andtrack the features of several.