Detecting intrinsically two-dimensional image structures using local phase

This paper presents a novel approach towards detecting intrinsically two-dimensional (i2D) image structures using local phase information. The local phase of the i2D structure can be derived from a curvature tensor and its conjugate part in a rotation-invariant manner. By employing damped 2D spherical harmonics as basis functions, the local phase is unified with a scale concept. The i2D structures can be detected as points of stationary phases in this scale-space by means of the so call phase congruency. As a dimensionless quantity, phase congruency has the advantage of being invariant to illumination change. Experiments demonstrate that our approach outperforms Harris and Susan detectors under the illumination change and noise contamination.