A priori knowledge of the image support, often called the support constraint, when applied to a raw image formed by an imaging system leads, by means of convolution with the support spectrum, to a mixing of the spatial frequencies in the image. For a noisy raw image, such mixing causes motion of noise in its spatial-frequency spectrum. A simple model for describing the motion of atmospheric-turbulence-induced noise in the spectrum of a star image formed by a ground-based system under the application of a support constraint is presented. The transport of noise occurs in this model by a combination of ballistic motion, or drift, and diffusive spreading. For an inversion-symmetric support, the drift is absent, and noise transport is exclusively diffusive. An analytical expression for the reduction of noise that such diffusive spreading in the spatial-frequency plane can facilitate, when a circular support of arbitrary size is employed, is derived.
© 1999 Optical Society of America
(100.1830) Image processing : Deconvolution
(100.2980) Image processing : Image enhancement
(100.3010) Image processing : Image reconstruction techniques
(100.3190) Image processing : Inverse problems
(110.4280) Imaging systems : Noise in imaging systems
Sudhakar Prasad, "Dynamics of turbulence-induced noise in image deconvolution with support constraint," J. Opt. Soc. Am. A 16, 1769-1778 (1999)