SC2FILTERMAP - Filter a 2-d map

Description:

This routine takes the FFT of a 2D map, applies a Fourier-space filter, and then transforms back to real-space before writing out. Currently the only available filter is a whitening filter which is measured using a supplied reference image.

Parameters:

FILT_EDGEHIGH = _REAL (Write)

High-pass filter frequency (1/arcsec)

FILT_EDGELOW = _REAL (Write)

Low-pass filter frequency (1/arcsec)

IN = NDF (Read)

Input files to be transformed.

MSG_FILTER = _CHAR (Read)

Control the verbosity of the application. Values can be NONE (no messages), QUIET (minimal messages), NORMAL, VERBOSE, DEBUG or ALL. [NORMAL]

OUT = NDF (Write)

Output transformed files.

OUTFILTER = NDF (Write)

Optional NDF for the filter.

WHITEN = _LOGICAL (Read)

If selected, measure azimuthally-averaged angular power spectrum in WHITEREFMAP, fit a model A/F$\wedge$B $+$ W, and apply its complement to the FFT of the data (normalized to W). AZAVSPEC is set implicitly. [FALSE]

WHITEREFMAP = NDF (Read)

Reference map in which to measure whitening filter. [FALSE]

ZEROBAD = _LOGICAL (Read)

Zero any bad values in the data before taking FFT. [TRUE]

Notes:

Transforming data loses the VARIANCE and QUALITY components.

Related Applications

SMURF: SC2MAPFFT