Application of a Noise-Smoothing Filter Based on Adaptive Windowing to Penumbral Imaging

摘要

Penumbral imaging is a technique which uses the facts that spatial information can be recovered from the shadow or penumbra that an unknown source casts through a simple large circular aperture. The technique is based on a linear deconvolu- tion. In this paper, a two-step method is proposed for decoding penumbral images. First a local-statistic filter based on adap- tive windowing is applied to smooth the noise; then, followed by the conventional linear deconvolution. The simulation results show that the reconstructed image is dramatically improved in comparison to that without the noise-smoothing filtering, and the proposed method is also applied to real experimetal x-ray imaging.