Abstract:

In this paper, a new algorithm is proposed based on the EMD (empirical mode decomposition) speckle reduction and tophat transform. First, we use EMD to every column signal of the image to get the IMF signals, deduce the first and second IMF signals from the original signal to get a coarse-processed image, and then do the same to the row signal of the coarse-processed image. The speckle can be greatly reduced with this algorithm. Furthermore, the local background of non-homogeneity caused by waves is greatly reduced with tophat transform. The signal-to-clutter-rate of the image is greatly enhanced, which is favorable for detection. The simulation results show the effectiveness of the algorithm.

Key words: speckle reduction, ship detection, EMD (empirical mode decomposition), tophat transform