Constrained phase congruency: simultaneous detection of interest points and of their orientational scales

The constrained phase congruency transform (CPCT) is a feature detector which simultaneously detects interest points as well as their scale in various orientations. Features are detected by constraining the local phase in a few scales. Only four easy-to-detect phases are used in the computations. They correspond to symmetry and antisymmetry in their neighborhood. The scale at any location and orientation is determined by the scale for which the focal energy is maximizes. The CPCT detects the features in Mach bands and in sinusoidal waves. This cannot be done simply by looking for local maxima in intensity gradient nor by looking for local energy maxima. I conjecture that constraining the general phase congruency is sufficient for feature detection. The correct detection of features location and of their scale is demonstrated