Coded apertures for imaging problems are typically based on arrays having perfect cross-correlation properties. These arrays, however, guarantee a perfect point-spread function in far-field applications only. When these arrays are used in the near-field, artifacts arise. We present a mathematical derivation capable of predicting the shape of such artifacts. The theory shows that methods used in the past to compensate for the effects of background nonuniformities in far-field problems are also effective in reducing near-field artifacts. The case study of a nuclear medicine problem is presented to show good agreement of simulation and experimental results with mathematical predictions.
© 2001 Optical Society of America
Roberto Accorsi and Richard C. Lanza, "Near-Field Artifact Reduction in Planar Coded Aperture Imaging," Appl. Opt. 40, 4697-4705 (2001)