Abstract: A method of identifying features within a dataset such as an image comprises applying a multiscale transform such as a dual tree Complex Wavelet Transform to generate a plurality of scale-related transform levels each having a plurality of transform coefficients defining magnitude and phase; determining the phase difference between a first coefficient on one level, and a second coefficient on the same or a different level; and identifying the feature in dependence on the phase difference. Each quadrant of the phase difference, when plotted as an angle, is indicative of a different type of feature. The invention is equally applicable to the identification of two-dimensional features such as images, as well as to the identification of features within one-dimensional data streams such as audio.