maskborder_nest


For a input binary mask in NESTED ordering, maskborder_nest identifies the pixels located on the inner boundary of invalid regions

Location in HEALPix directory tree: src/f90/mod/mask_tools.F90 


FORMAT

call maskborder_nest( nside, mask_in, mask_out, nbordpix, [ border_value] )

Arguments appearing in italic are optional.


ARGUMENTS

name & dimensionality kind in/out description
       
nside I4B IN The Nside value of the input mask.
mask_in(0:Npix-1) I4B IN Input binary NESTED-ordered mask. Npix = 12*nside*nside
mask_out(0:Npix-1) I4B OUT Output NESTED-ordered mask, in which inner border pixels (defined as 0-valued and adjacent to 1-valued pixels) take the value 2 (or border_value). Can be the same array as mask_in.
nbordpix I4B OUT Number of border pixels found
border_value I4B IN value to be given to border pixels in output mask. default:2.


EXAMPLE:

use healpix_types
use healpix_modules
...
call maskborder_nest(nside, mask_in, mask_in, nbordpix)
For a binary input mask mask_in, it will look for border pixels and output their number in nborpix. In this example the mask_in will be modified so that border pixels take value 2 on output.


MODULES & ROUTINES

This section lists the modules and routines used by maskborder_nest.

mask_tools
mask processing module (see related routines below)


RELATED ROUTINES

This section lists the routines related to maskborder_nest

dist2holes_nest
angular distance to closest invalid pixel of the given mask
fill_holes_nest
turn to valid all pixels located in 'holes' containing fewer pixels than the given threshold
maskborder_nest
identify inner boundary pixels of 'holes' for given mask
size_holes_nest
returns size (in pixels) of holes found in input mask

Version 3.31, 2017-01-06