Gamma ISP: Reference Manual

mask_data

ANSI-C program: mask_data.c

NAME
mask_data - Mask data using a Sun or BMP format raster image

SYNOPSIS
mask_data <data_in> <width> <data_out> <mask> [format_flag]

<data_in>	(input) data file (float or fcomplex format)
<width>	width of input data file
<data_out>	(output) data file, same data format as input
<mask>	(input) mask file, Sun raster or BMP format, 8-bits/pixel NOTE: mask file must have the same width as the input data file
[format_flag]	input/output data format: 0: FLOAT (default) 1: FCOMPLEX

EXAMPLE

mask_data 19990421_1999042.unw 2456 19990421_19990422.msk.unw 19990421_1999042.cc_msk.ras 0

The unwrapped phase is set to 0 where 19990421_1999042.cc_msk.ras has value 0. In this case the mask file was created using the program rascc_mask to generate an 8-bit raster file (Sun raster or BMP format). The output validity mask is a combined coherence and intensity display with all samples of the image with coherence below the thresholds set to 0. The user can select thresholds for both correlation and relative intensity.

DESCRIPTION
mask_data is used to set values of an input data file (either fcomplex or float format) to zero based on the values contained the 8-bit/pixel mask file. The mask file is either Sun raster or BMP format.

One application of mask data is with phase unwrapping. When unwrapping phase using mcf, it is often better to mask the unwrapped phase after unwrapping, rather than before because the masking operation also recreates phase inconsistances that must be resolved by the unwrapping procedure. In images where there are large regions that are incoherenent, the result will often be better using mask_data after unwrapping by mcf.

mask_data can also be used to remove noisy regions from an image to improve the display. The mask file can be created using a program such as gimp. (www.gimp.org)

SEE ALSO
mcf, rascc_mask