A restoration scheme is proposed for space-variant image degradation resulting from curvature of field in imaging systems. Providing that the inverse transfer function of an imaging system is represented as the Taylor polynomial series
due to the fact that the product of the inverse transfer function and a degraded image is the Fourier transform of the corresponding restored image
and consequently
the image is restored by computing the linear combination of the original image and its derivative images. The actual restoration results demonstrate that the restoration scheme makes the definition of a space-variant degraded photo roughly uniform in the entire image region.
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