boxit

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0.1.6 boxit

Requires:

Synopsis
Box regions in image above given threshold value.

Description

Returns a list of boxes, one for each contiguous set of pixels above the threshold value. If given ”regionfile”, outputs boxes in regionfile+’.rgn’

Arguments


Inputs
imagename		Name of image to threshold
		allowed:	string
		Default:
regionfile		Output region file
		allowed:	string
		Default:
threshold	mJy	Threshold value. Must include units.
		allowed:	doublemJy
		Default:	0.0
maskname		Output mask name (optional).
		allowed:	string
		Default:
chanrange		Range of channel ids
		allowed:	string
		Default:
polrange		Range of polarization ids
		allowed:	string
		Default:
minsize		Minimum number of pixels for a boxable island
		allowed:	int
		Default:	2
diag		Count diagonal connections?
		allowed:	bool
		Default:	False
boxstretch		Increase box sizes by this many pixels beyond thresholded pixels.
		allowed:	int
		Default:	1
overwrite		Overwrite existing region file?
		allowed:	bool
		Default:	False

Returns
void

Example

       This tool finds all 2-dimensional (RA/dec) regions in the given
       4D (only!) image which are contiguous sets of pixels (islands) above the given ]
       threshold.  It creates a box for each island, a rectangular "cutout".
       The boxes are stored as regions in the output regionfile.  Works on
       multi-plane images, but only boxes 2-D regions in each plane.
       (Doesn’t create cubes/3D boxes.)

       NOTE: THIS TASK WILL NOT WORK ON IMAGES THAT DO NOT HAVE 4 DIMENSIONS WHICH INCLUDE
       A DIRECTION COORDINATE, A SPECTRAL COORDINATE, AND A STOKES COORDINATE. If your image
       has, eg just a direction coordinate, you can add the required axes using ia.adddegaxes()
       and remove them post-run with imsubimage with dropdeg=T.

       imagename -- Name of input images:
               default: none; example: imagename=’myimage.image’
       regionfile -- Name of output region file (adds extension .rgn).
               default: none; if not given uses imagename+’.rgn’
       threshold -- value (with units) to use for island threshold.
               default: 0.0.
       maskname -- Optional output mask name.
               default: ’’ (do not write mask image)
       chanrange -- Range of channel ids
               default: ’’ (find boxes for all channels)
               example: ’5~7’ (find boxes for channel 5,6,7
       polrange -- Range of polarization ids
               default: ’’ (find boxes for all polarizations)
               example: ’0~1’ (find boxes for polarization 0,1
       minsize -- minimum size of island to get a box (in number of pixels)
               default: 2
       diag -- count diagonal connections as same island or not
               default: False
       boxstretch -- number of pixels to increase outward size of each box; can
               range from -1 to 5.
               default: 1
       overwrite -- Overwrite existing region file and/or mask?
               default: False.  If False, gives warning if file exists.

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