DATAMANIP (kdatamanip) functions


LIBRARY ROUTINE

lkwiener - perform Wiener filtering (restoration) in Fourier frequency domain

LIBRARY CALL

int lkwiener(kobject in_obj, kobject psf_obj, double wiener, kobject out_obj)

INPUT

OUTPUT

RETURN VALUE

TRUE (1) on success, FALSE (0) otherwise

DESCRIPTION

Perform restoration of data in the spatial domain by Wiener filtering in the frequency domain. The idea is to deconvolve the blurring function from the blurred data. A few problems exist in performing this operation, as described in great detail in any good image processing book.

A full implementation of a Wiener filter requires detailed knowledge of the signal and noise power spectra. Many times this information is simply unavailable or is very poorly known. In such situations, it is convenient to assign some constant value to the SNR and use that in the Wiener filter implentation. This is a somewhat extreme restriction of the Wiener filter, but it makes the filter very easy to use and can give much better results than the pseudoinverse filter in lkinverse().

This routine implements the filter described in K.R. Castleman, "Digital Image Processing", Prentice-Hall 1979, ISBN 0-13-212365-7, p281 Eq. 2 with the variable SNR term given as the Weiner parameter constant.

ADDITIONAL INFORMATION

none

EXAMPLES

none

SIDE EFFECTS

none

RESTRICTIONS

Restrictions on data or input as applicable

MODIFICATION

none

FILES

$DATAMANIP/objects/library/kdatamanip/src/lkwiener.c

SEE ALSO

kdatamanip(3)

COPYRIGHT

Copyright (C) 1993 - 1997, Khoral Research, Inc. ("KRI") All rights reserved.