Phase singularities in scale-space

摘要

This paper concerns the use of phase information from band-pass signals for the measurement of binocular disparity, optic flow and image orientation. Towards this end, one of the important properties of band-pass phase information is its stability with respect to small geometric deformations and contrast changes. However, in particular regions phase can also be very unstable due to the occurrence of phase singularities. We discuss the existence of phase singularities, and their relation to the neighbourhoods where phase is unreliable. Moreover, we present a simple method for detecting these regions of instability.