GAMMA Interferometric Point Target Analysis Software (IPTA): Reference Manual

msk_pt

ANSI-C program: msk_pt.c

NAME
msk_pt - generate a point list and mask vector using a raster image mask

SYNOPSIS
msk_pt <plist1> <pmask1> <mask> <plist2> <pmask2> <rlks2> <azlks>

<plist1>	(input) point list 1 (int) (enter - for none)
<pmask1>	(input) point data stack of mask values (uchar pmask[i]=0 excludes point i) (enter - for none)
<mask>	(input) raster image file (8-bit/pixel Sun raster or BMP format) points located in regions set to 0 are masked out
<plist2>	(output) point list 2 (int)
<pmask2>	(output) output mask, matches length of plist1 if plist2 is not specified
<rlks>	mask file range looks relative to the point SLC coordinates
<azlks>	mask file azimuth looks relative to the point SLC coordinates

EXAMPLE
msk_pt pt_1 pmsk1 mask.ras pt_2 - 1 5 pt_2 contains the point coordinates of all points in pt_1 that lie within the non-zero regions of mask.ras. The mask file was generated using 5 azimuth looks and 1 range look.

msk_pt pt_1 pmsk1 mask.ras - pmsk2 1 5

In this example, pmsk2 has the same number of entries as pmsk1. Points that lie within regions of mask.ras that are 0 have the mask value set to 0 in pmsk2. Points that are masked out in pmsk1 are also masked out in pmsk2.

INSTALLATION
Source code msk_pt.c in ./IPTA/src, executable version msk_pt in ./IPTA/bin

DESCRIPTION
msk_pt is a program that is used to select subsets of points from a point list based upon a raster mask file. It can also be used to modify or generate a mask based on a raster image mask file. The mask image is an 8-bit/pixel Sun raster or BMP format file. Often the mask image is derived from a multi-look image. Since the point coordinates are in SLC coordinates (range looks = 1, azimuth looks = 1) the number of range and azimuth looks of the image used to derive the mask are required as input on the command line.

<></> <>OPTIONS
If no input point list is entered on the command line, then the coordinates of all the points within the mask region are stored in pt_2.
</>
If an output point list pt_2 is specified, all points that lie within the non-zero regions of the mask are written to the output point list pt_2. If pt_2 is not specified, the values of pmsk2 are set to 1 where ever the mask image is non-zero and pmsk1 is non zero. In this later case, the number of entries in pmsk2 is the same as the number of points in pt_1.\

<>SEE ALSO
thres_im_pt, thres_msk_pt, cat_pt, ipta.h.</>