Symmetry detection based on phase information and its application in DR fundus image

Symmetry exists widely in the real world and plays a remarkable role in perception problems. The existing symmetry detection algorithms are mainly based on luminance or gradient information. Upon analyzing the relationship between symmetry and phase, based on phase congruency, we propose a phase-based symmetry detection (PSD) algorithm. PSD is calculated based on log Gabor wavelet. We test it with fundus image and the experiments show that this algorithm can be applied directly to original images without segmentation.