casa6

from casac import casac

import os

import numpy as np

import pdb

iaim=casac.image()

iamask=casac.image()

qa=casac.quanta()

rg=casac.regionmanager()

​

def automask(image='', maskimage='', fracofpeak=0, rmsthresh=3.0, resolution=None, twopass=False):

    """

    image : dirty image or residual to mask

    maskimage: name of mask to create. If already existant has to be same shape 

    and coordsys as image

    fracofpeak : Fraction of peak to use as masking threshold (a number between 0 and 1)

                       if 0  then rmsthresh or  a value based on the rms of the image is used

    rmsthresh : Threshold in sigma  to use; default is 3 sigma

    resolution: if image has no restoring beam ..this value is used for resolution of 

                     image (e.g '4arcsec')

    twopass: set to True if faint fluffy stuff is wanted else false if a less agressive masking 

    is needed especially a multi pass masking after some cleaning

​

    """

#    print '2pass ', twopass

    iaim.open(image)

    stat=iaim.statistics(mask='abs("'+image+'") > 0.0')

    csys=iaim.coordsys()

    rb=iaim.restoringbeam()

    numpix=10

    shp=iaim.shape()

    resol=qa.quantity(resolution, 'arcsec')

    if(shp[0] < 10):

        raise TypeError, 'you cannot be serious... less than 10 pixels image'

    if(len(rb) ==0 and resolution==None):

        raise ValueError, 'No restoring beam or resolution given'

    if(len(rb) > 0):

        numpix=2*(int(2.0*abs(qa.div(rb['major'], qa.convert(csys.increment('q')['quantity']['*1'],rb['major']['unit']))['value']))/2)

    elif(resol['value'] != 0.0):

         numpix=2*(int(2.0*abs(qa.div(resol, qa.convert(csys.increment('q')['quantity']['*1'],resol['unit']))['value']))/2)

    else:

        numpix=iaim.shape()[0]/10;

    if(numpix < 5):

        numpix=6

    #print 'NUMPIX', numpix

    if((fracofpeak >0) and (fracofpeak < 1)):

        rms=stat['max'][0]*fracofpeak

    elif(rmsthresh !=0):

        rms=stat['rms'][0]*rmsthresh

    else:

        rms=stat['rms'][0]*3.0

    ib=iaim.rebin('__rebin.image', [numpix, numpix, 1, 1], overwrite=True)

    ib.done()

    ib.open('__rebin.image')

    if(twopass):

        thresh=5.0*rms/np.sqrt(float(numpix))

    else:

        thresh=3.0*rms/np.sqrt(float(numpix))

    ic=ib.imagecalc(outfile='__thresh.image', pixels='iif(abs("__rebin.image")> '+str(thresh)+',1.0,0.0)', overwrite=True)

    ib.remove(done=True, verbose=False)

    ie=ic.regrid(outfile='__threshreg.image', shape=shp, csys=csys.torecord(), axes=[0,1], overwrite=True)

    ic.remove(done=True, verbose=False)

    convpix=str(numpix/2)+'pix' if(twopass) else str(numpix)+'pix'