########################################################################3
# task_imsmooth.py
#
# Copyright (C) 2008, 2009
# Associated Universities, Inc. Washington DC, USA.
#
# This script is free software; you can redistribute it and/or modify it
# under the terms of the GNU Library General Public License as published by
# the Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# This library is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
# License for more details.
#
# You should have received a copy of the GNU Library General Public License
# along with this library; if not, write to the Free Software Foundation,
# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
#
# Correspondence concerning AIPS++ should be adressed as follows:
# Internet email: aips2-request@nrao.edu.
# Postal address: AIPS++ Project Office
# National Radio Astronomy Observatory
# 520 Edgemont Road
# Charlottesville, VA 22903-2475 USA
#
# <summary>
# CASA task for smoothing an image, by doing Forier-based convolution
# on a CASA image file.
# </summary>
#
# <reviewed reviwer="" date="" tests="" demos="">
# </reviewed
#
# <author>
# Shannon Jaeger (University of Calgary)
# </author>
#
# <etymology>
# imsmooth stands for image smoothing
# </etymology>
#
# <synopsis>
# task_imsmooth.py is a Python script providing an easy to use task
# for smoothing an image.
#
# The convolv2d function of the image tool is used to do the work,
# a description of this function can be found at
# http://casa.nrao.edu/docs/casaref/image.convolve2d.html#x27-270001.1.1
#
# </synopsis>
#
# <example>
# <srcblock>
# # The following code snippet find the 1-moments, intensity-weighted
# # coordinate, often used for finding velocity fields.
# imsmooth( imagename='myimage', kernel='gaussian', outfile='myimage.smooth' )
#
#
# </example>
#
# <motivation>
# To provide a user-friendly method to smooth images.
# </motivation>
#
# <todo>
# </todo>
from __future__ import absolute_import
import inspect
import os
import sys
import numpy
# get is_CASA6 and is_python3
from casatasks.private.casa_transition import *
if is_CASA6:
from casatools import image, regionmanager, quanta
from casatasks import casalog
from .ialib import write_image_history
_qa = quanta( )
else:
from taskinit import *
from ialib import write_image_history
image = iatool
regionmanager = rgtool
# not a local tool
_qa = qa
from casatasks.private.callabletask import log_origin_setter
@log_origin_setter
def imsmooth(
imagename, kernel, major, minor, pa, targetres, kimage, scale, region,
box, chans, stokes, mask, outfile, stretch, overwrite, beam
):
ikernel = kernel.startswith('i')
ckernel = kernel.startswith('c')
bkernel = kernel.startswith('b')
gkernel = kernel.startswith('g')
if (
not (
gkernel or bkernel or ckernel or ikernel
)
):
raise ValueError('Unsupported kernel, ' + kernel)
if (not ikernel and type(beam) == str):
if len(beam) != 0:
err = "beam cannot be a non-empty string"
casalog.post(err, "SEVERE")
raise Exception(err)
beam = {}
# First check to see if the output file exists. If it
# does then we abort. CASA doesn't allow files to be
# over-written, just a policy.
if ( len( outfile ) < 1 ):
outfile = 'imsmooth_results.im'
casalog.post( "The outfile paramter is empty, consequently the" \
+" smoothed image will be\nsaved on disk in file, " \
+ outfile, 'WARN')
_myia = image()
_myia.dohistory(False)
retia = image()
_myia.open(imagename)
mycsys = _myia.coordsys()
myrg = regionmanager()
reg = myrg.frombcs(
mycsys.torecord(), _myia.shape(), box, chans,
stokes, "a", region
)
myrg.done()
mycsys.done()
_myia.done()
# If the values given are integers we assume they are given in
# arcsecs and alter appropriately
if not ikernel:
if isinstance(major, (int, float)):
major=str(major)+'arcsec'
if isinstance(minor, (int, float)):
minor=str(minor)+'arcsec'
if isinstance(pa, (int, float)):
pa=str(pa)+'deg'
try:
outia = None
if ( gkernel or ckernel):
_myia.open(imagename)
if ckernel:
beam = _myia.commonbeam()
# add a small epsilon to avoid convolving with a null beam to reach
# a target resolution that already exists
beam['major'] = _qa.mul(beam['major'], 1 + 1e-10)
beam['minor'] = _qa.mul(beam['minor'], 1 + 1e-10)
major = ""
minor = ""
pa = ""
targetres = True
if (beam and (major or minor or pa)):
raise ValueError("You may specify only beam or the set of major/minor/pa")
if not beam:
if not major:
raise ValueError("Major axis must be specified")
if not minor:
raise ValueError("Minor axis must be specified")
if not pa:
raise ValueError("Position angle must be specified")
outia = _myia.convolve2d(
axes=[0,1], region=reg, major=major,
minor=minor, pa=pa, outfile=outfile,
mask=mask, stretch=stretch, targetres=targetres,
overwrite=overwrite, beam=beam
)
elif (bkernel ):
if not major or not minor:
raise ValueError("Both major and minor must be specified.")
# BOXCAR KERNEL
#
# Until convolve2d supports boxcar we will need to
# use sepconvolve to do this.
#
# BIG NOTE!!!!!
# According to Gaussian2D documentation the default position
# angle aligns the major axis along the y-axis, which typically
# be lat. So this means that we need to use the major quantity
# on the y axis (or 1) for sepconvolve.
_myia.open( imagename )
casalog.post( "ia.sepconvolve( axes=[0,1],"+\
"types=['boxcar','boxcar' ],"+\
"widths=[ "+str(minor)+", "+str(major)+" ],"+ \
"region="+str(reg)+",outfile="+outfile+" )",\
'DEBUG2' )
#retValue = ia.sepconvolve( axes=[0,1], types=['box','box' ],\
# widths=[ minor, major ], \
# region=reg,outfile=outfile )
outia = _myia.sepconvolve(
axes=[0,1], types=['box','box' ],
widths=[ minor, major ],
region=reg,outfile=outfile,
mask=mask, stretch=stretch,
overwrite=overwrite
)
elif ikernel:
_myia.open(imagename)
outia = _myia.convolve(
outfile=outfile, kernel=kimage, scale=scale, region=reg,
mask=mask, overwrite=overwrite, stretch=stretch
)
else:
raise ValueError('Unrecognized kernel type: ' + kernel)
try:
param_names = imsmooth.__code__.co_varnames[:imsmooth.__code__.co_argcount]
if is_python3:
vars = locals( )
param_vals = [vars[p] for p in param_names]
else:
param_vals = [eval(p) for p in param_names]
write_image_history(
outia, sys._getframe().f_code.co_name,
param_names, param_vals, casalog
)
except Exception as instance:
casalog.post("*** Error \'%s\' updating HISTORY" % (instance), 'WARN')
finally:
_myia.done()
if outia: outia.done()