Image Reconstruction From Strongly Scattering Penetrable Objects Using a Differential Cepstral Filter
Abstract
Conventional algorithms for media characterization in diffraction tomography rely on weakly scattering approximations such as the Born or Rytov methods. In this report, we investigate the utility of a nonlinear filtering procedure applied to single-view backpropagated images of strongly scattering two-dimensional objects. With a single illumination direction and constant wave number k0, exact scattered far fields are backpropagated to form an image of the scattering potential times the total field. The multiplicative field, in this case, precludes one from ascertaining quantitative information on the scattering potential. We apply a differential cepstral filter to single-view backpropagated images in order to remove the perturbing field. Phase wrapping problems associated with cepstral filtering procedures are avoided in the differential cepstrum, since phase ambiguities introduced by the complex algorithm are avoided in its definition. Exact scattering solutions are used from several strongly scattering cylinders ranging from k0alpha(square root of (epsilon tau) - 1) = 2 to k0alpha(square root of (epsilon tau) - 1) = 41 where alpha is the maximum dimension of the object and epsilon tau is the relative permittivity. For the lower range, the filtered single-view backpropagated images are superior to the unfiltered. As the range increases, object features become less resolved due to the limited Fourier data available. Results and limitations of the proposed methods are discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1996
- Accession Number
- ADA345619
Entities
People
- John B. Morris
Organizations
- Rome Laboratory