ANSI-C program: multi_cpx.c
NAME
multi_complex - This program is used to resample a selected
region of a complex image. Both decimation and oversampling are
supported.
SYNOPSIS
multi_cpx <cpx_input > <OFF_par_in >
<cpx_output> <OFF_par_out> [rlks] [azlks] [loff]
[nlines] [roff] [nsamp]
| <cpx_input> | input complex image file |
| <OFF_par_in> | interferogram/offset parameter file for input image |
| <cpx_output> | output multi-look or interpolated complex data file |
| <OFF_par_out> | interferogram/offset parameter file for output, use existing parameter file if available |
| [rlks] | number of range looks, values < -1, interpreted as an image magnification factor (default=1) |
| [azlks] | number azimuth looks, values < -1, interpreted as an image magnification factor (default=1) |
| [loff] | line offset to starting line (default=0) |
| [nlines] | number of lines (default=0, to end of file) |
| [roff] | offset to starting range sample (default=0) |
| [nsamp] | number of range samples to extract (default=to end of line) |
EXAMPLES
Average and decimate a complex flattened interferogram file by a
factor of 2:
multi_cpx 8560_8059.flt 8560_8059.off 8560_8059_2.flt
8560_8059_2.off 2 2
DESCRIPTION
multi_cpx extracts a region from a complex data file and
averages the data using the rlks and azlks
parameters defined on the command line. If the number of range
and azimuth looks is set to 1, then the desired region is
extracted and the values are not altered. If the output image is
decimated, averaging of the data is performed to reduce noise,
using rlks samples in range and azlks azimuth
samples for each output sample.
Alternately, the program can be used to oversample a segment of an image with the magnification factors specified on the command line. These integer factors are given as negative rather than positive values for the rlks and azlks parameters. Interpolation in one dimension and decimation in the other is not permitted. Bilinear interpolation is used to resample the data.
Normally a new parameter file describing the processed output image geometry is created. When interpolating data however, the program first checks if there is an existing parameter file. If it exists is is used to determine the size of the output image to ensure that the oversampled images have the same geometry as other data sets prior to averaging and subsampling. In the case of an existing parameter file, the parameters loff, nlines, roff, and nsamp must all be default values.SEE ALSO
typedef_ISP.h
© Copyrights for Documentation, Users Guide and Reference Manual by Gamma Remote Sensing, 2000.
UW, CW, last change 3-Nov-2000.