Scale Adaptive Side Window Bilateral Filter

Recently a filtering method based on side windows has been reported. Although this method has strong ability to preserve edge structure, its ability to smooth textures is weaker than using a full window. In this paper, we propose a scale adaptive side window-based bilateral filter (SASWBF). An expanding ratio parameter is designed to control the side window varying to the full window. To adapt the size of spatial kernel at each pixel, the scale of the filtering window is estimated using a structure measure. A bilateral filter using Fourier basis is adopted to accelerate the filter processing. The computational complexity of the proposed smoothing filter does not depend on the window size and thus is in almost constant time. Our experimental results demonstrate that the proposed filter performs well.