We have simulated the performance of various apertures used in Coded Aperture Imaging - optically. Coded pictures of extended and continuous-tone planar objects from the Annulus, Twin Annulus, Fresnel Zone Plate and the Uniformly Redundant Array have been decoded using a noncoherent correlation process. We have compared the tomographic capabilities of the Twin Annulus with the Uniformly Redundant Arrays based on quadratic residues and m-sequences. We discuss the ways of reducing the 'd. c.' background of the various apertures used. The non-ideal System-Point-Spread-Function inherent in a noncoherent optical correlation process produces artifacts in the reconstruction. Artifacts are also introduced as a result of unwanted cross-correlation terms from out-of-focus planes. We find that the URN based on m-sequences exhibits good spatial resolution and out-of-focus behaviour when imaging extended objects.
| Date of Award | 1981 |
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| Original language | English |
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- Possibilities
- limitations
- coded aperture imaging
- twin annulus
- biomedical imaging
- y-ray imaging
- tomography
Possibilities and limitations of coded aperture imaging
Silva, R. L. (Author). 1981
Student thesis: Doctoral Thesis › Doctor of Philosophy