ldarpsd(3)

LIBRARY ROUTINE
ldarpsd - 1D Autoregressive (AR) PSD

LIBRARY CALL
#include "vinclude.h"
int ldarpsd ( image, nfreq, arfrom, estimate, normalize, procdir )
int nfreq, procdir, normalize,arfrom,estimate;
struct xvimage *image;

INPUT

image
    pointer to VIFF structure containing image data to be processed.

nfreq
    number of data points for PSD estimate (nfreq >= 0).

arfrom
    AR coefficients: come from a tapped delay filter(0) or from a lattice filter(1).

estimate
    Spectral estimate: phase spectral estimate(0) or PSD estimate(1).

normalize
    normalize PSD estimate: if yes (0) then normalize, else no (1) do nothing.

procdir
    process direction: 0 indicated vector oriented processing, 1 indicates band oriented processing.

OUTPUT

image
    pointer to VIFF structure containing image data after processing.

Return Value:
    1 on success, 0 on failure.

MODIFICATIONS

Jeremy Worley Mon Feb 17 23:24:36 MST 1992
    1. argument declarations for arfrom and estimate in ldarpsd() missing. 2. propertype() implicitly declared...made explicit int. 3. larpsde() dropped off the end without a return() call.

DESCRIPTION
darpsd 1D AR PSD/Phase Estimation. Determines the 1D autoregressive (AR) PSD and Phase spectral estimate of the input file. The input file consists of autoregressive parameters. The autoregressive parameters can originate either on a tapped-delay or lattice filter realizations. The user is allowed to extrapolate the PSD or Phase estimate to the desired number of points. It can operate on Real and Complex data.

NOTE 1: complex data is expected to be in rectangular (not polar) form.

NOTE 2: if input data is real the Phase spectra will be 0.0.

darpsd does not work on explicit location data and will return an error when such a file is encountered. No output file will be created. darpsd works only on VFF_TYP_FLOAT or VFF_TYP_COMPLEX data files.

Input/Output Files

The input file must be of type VFF_TYP_FLOAT or VFF_TYP_COMPLEX. The output file returned will be of size specified by the user. If the data is of type VFF_TYP_COMPLEX and complex aithmetic is selected then the output file will be of type VFF_TYP_FLOAT. *********************************************************************

Process direction

Data can be processed with either band or vector orientation (-d option). The default data processing direction is in the vector direction (-d = 0). pixel location. The direction of processing can be changed so that each band is processed as a signal (instead of each vector being a signal) by setting the -d option to 1.

SEE ALSO
darpsd(1), intro(3), vipl(3), verror(3), vutils(3)

RESTRICTIONS
works only on VFF_TYP_COMPLEX and VFF_TYP_FLOAT.

ldarpsd does not work on explicit location data and will return an error when such a data file is encountered.

AUTHOR
Ramiro Jordan

COPYRIGHT
Copyright 1992, University of New Mexico. All rights reserved.