Comparison between MDA and two edge detectors for SAR image analysis

A comparison is performed among three edge detectors operating on Synthetic Aperture Radar (SAR) images: Canny filter, Ratio detector and Multilevel Deterministic Annealing with a speckle noise model. The first method represents classical edge extractors, based on a regularised estimation of the derivatives of the image function. The Ratio Detector is an example of a Constant False Alarm Rate methods used for edge detection in speckle-noise, which rely on a detection criterion independent from the average gray-level of the decision region. The method defined Multilevel Deterministic Annealing is based on a non-linear statistical criterion which takes into account not only local properties of the image function, but also its global characteristics. The three detectors are evaluated on the basis of false-alarm and detection errors computed on the basis of the apriori known output of a synthetic scene. A qualitative evaluation on real images is also provided. It is shown that Multilevel Deterministic Annealing provides better results despite of a higher computational load.