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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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