Features enhancement on SAR-ERS 1 images: HK-filter

In order to remove the speckle on radar images while preserving the radiometrical and spatial resolution of the initial image, various filtering techniques have been proposed. These techniques are mainly based on a statistical and/or a morphological approach. The filtering presented here belongs to the first class. The statistical distribution of the backscatter values of the initial image is observed inside a given neighborhood and controlled by three parameters (size of the neighborhood, radiometric range and length of the isolated elements). This technique has been applied on two SAR-ERS1 scenes (Spitsbergen glaciers and Mount Pinatubo in the Philippines). While reducing the speckle, the HK-Filter seems able to underline the linear features.