Local tomography

Adel Faridani, Erik L. Ritman, Kennan T. Smith

Research output: Contribution to journalArticlepeer-review

161 Scopus citations


Tomography produces the reconstruction of a function f from a large number of line integrals of f. Conventional tomography is a global procedure in that the standard convolution formulas for reconstruction at a single point require the integrals over all lines within some plane containing the point. Local tomography, as introduced initially, produced the reconstruction of the related function Λf, where Λ is the square root of -Δ, the positive Laplace operator. The reconstruction of Λf is local in that reconstruction at a point requires integrals only over lines passing infinitesimally close to the point, and Λf has the same smooth regions and boundaries as f. However, Λf is cupped in regions where f is constant. Λ-1f, also amendable to local reconstruction, is smooth everywhere and contains a counter-up. This article provides a detailed study of the actions of Λ and Λ-1, and shows several examples of what can be achieved with a linear combination. It includes the results of x-ray experiments in which the line integrals are obtained from attenuation measurements on two-dimensional image intensifiers and fluorescent screens, instead of the usual linear detector arrays.

Original languageEnglish (US)
Pages (from-to)459-484
Number of pages26
JournalSIAM Journal on Applied Mathematics
Issue number2
StatePublished - 1992

ASJC Scopus subject areas

  • Applied Mathematics


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