Improving precision of location determination of interest point in image detection with phase congruency based approach

Purpose. Most existing methods for determining location of interest point in image detection are, in our opinion, still deficient in precision. We present a phase congruency approach that uses log-Gabor wavelets and can improve such precision considerably because phase congruency is a dimensionless measure that remains invariant when changes occur in brightness and contrast. In the full paper, we explain our phase congruency approach in much detail; here we just list the three topics discussed in the detailed explanation; (1) log-Gabor filter; (2) phase congruency, whose subtopics are phase congruency of 1D signals (2.1), phase congruency of 2D signals(2.2); the subsubtopics of subtopic 2.2 are design of 2D filters (2.2.1), phase congruency of 1D features (2.2.2) and phase congruency of 2D features (interest points) (2.2.3); (3) flow chart of phase congruency. Experimental data for synthetic and real images are presented respectively in Fig. 3 and Fig. 4, each with 4 subfigures; the 8 subfigures show preliminarily that different kinds of interest points can be detected and located with good precision; thus the proposed method can be applied over wide classes of images.