Multiresolution spot detection by means of entropy thresholding

Many imaging applications deal with the detection of small targets or spots embedded within an inhomogeneous background. We present a method that acco mplishes a multiresolution detection on the wavelet-transformed image. The targets are separated from the background by the exploitation of Renyi's in formation, which is evaluated at the different decomposition levels of the wavelet transform. The scale-dependent candidate detections are successivel y combined by means of majority voting for final detection. Connections wit h results provided in different fields such as multifractal analysis, gener alized information measures in scale-space, and cross-entropy analysis in f ine-to-coarse transformations are discussed. Detection performance is inves tigated through an example from medical image analysis. (C) 2000 Optical So ciety of America [S0740-3232(00)02107-4] OCIS codes: 100.0100, 100.2000, 10 0.2960, 100.7410.