A New Coronal Loop Identification Method Based on Phase Congruency

We have tried to apply the enhanced image by a phase congruency method to the identification of coronal loop structures, and proposed a new coronal loop identification method (simply called the PCB method) based on the enhanced image by the phase congruency method. On account of the smooth morphological variation in the direction along a coronal loop, the propelling direction of coronal loop identification is restricted in a small range for improving the identified result. Beyond that, inspired by the structural characteristics of coronal loops, we firstly suggest that both the variation of propelling direction in the identification process and the magnitude of phase congruency at the identified point are simultaneously taken as the criterion to terminate the identification. Finally, several coronal images are used for testing our coronal loop identification method, and the result indicates that the enhanced image by the phase congruency method is really suitable for the coronal loop identification, and the coronal loop structures identified by the PCB method have simultaneously a good completeness and a high accuracy, hence, the PCB method is a set of practical and feasible method of automated coronal loop identification.