Filtering of dual-polarization radar images based on discrete cosine transform
Ruslan A. Kozhemiakin, Владимир Васильевич Лукин, Benoît Vozel, Kacem Chehdi · 2014
It is well known that filtering of multichannel images is, in general, more efficient compared to separate filtering of component data. This property can be exploited in processing dual-polarization radar images acquired by synthetic aperture radar (SAR) which are distorted by intensive speckle. Filtering of dual-polarization SAR images composed of HH and VV polarization components is studied. A novel filtering method based on 3D discrete cosine transform in blocks with preliminary normalization of data in blocks is proposed. Three quality metrics - MSE, MSE-L for locally active regions, and MSSIM - are analyzed to compare performance of the proposed method to component-wise DCT-based filtering and despeckling that employs logarithmic homomorphic transform. Advantages of the proposed method are shown quantitatively for simulated images and for real-life TerraSAR-X data.