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 $N_{\mathrm{side}}$ 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