Reconstruction of penumbral imaging based on a band-filtering algorithm

摘要

Penumbral imaging is a kind of 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 deconvolution. As we known that the information of the penumbral image is only contained in the penumbra (the edges of the image), so according to that principle, we proposed a two-step method for decoding penumbral images in this paper. First, an edgy-emphasizing algorithm using a band filter is applied to extract the penumbras (the image edges) in noisy penumbral images; then, followed by conventional linear deconvolution of only the penumbral edges. The simulation results show that the reconstructed image is dramatically improved in comparison to that with the conventional noise-removing filters, and the proposed method is also applied to real experimental x-ray imaging.