def register_images(files, params):
"""Register the images in the given files list.
Registered images are placed in the loc_output dir with prefix r_
"""
# Have we specified a registration template?
if params.registration_image:
reg = DS.Observation(params.registration_image, params)
else:
reg = DS.EmptyBase()
reg.fw = 999.0
for f in files:
if (f.fw < reg.fw) and (f.fw > 1.2):
reg = f
print('Registration image:', reg.name)
# Register images
for f in files:
if f == reg:
f.image = f.data
rf = params.loc_output + os.path.sep + 'r_' + f.name
IO.write_image(f.image, rf)
else:
f.register(reg, params)
# delete image arrays to save memory
del f.image
del f.mask
del f.inv_variance
del reg.data
del reg.image
del reg.mask
del reg.inv_variance
return(files)
def make_ref_image(params):
"""Make a reference image if it doesn't exist.
Requires a list of input images to combine, in the file given by
params.ref_image_list (default "ref_image_list.txt"). Assumes these
images are already registered and trimmed, and can be found in the
params.loc_trim directory.
Returns the ref image as a DIA data_structures Observation object
"""
refimname = params.ref_image
refimpath = os.path.join(params.loc_output, refimname)
if os.path.exists(refimpath):
refim = DS.Observation(refimpath, params)
print("Ref image %s exists. Not clobbering." % refimpath)
return (refim)
# read in a list of input images for creating the ref image
if not os.path.exists(params.ref_image_list):
print("Missing ref image list file %s" % params.ref_image_list)
return (None)
fin = open(params.ref_image_list, 'r')
ref_input_filenames = [f.strip() for f in fin.readlines()]
fin.close()
ref_image_list = get_observation_list(ref_input_filenames, params)
registered_ref_image_list = register_images(ref_image_list, params)
# Make the photometric reference image if we don't have it.
# Find stamp positions if required.
stamp_positions = DIA.make_reference(registered_ref_image_list,
params,
reference_image=refimname)
refim = DS.Observation(refimpath, params)
# Register the newly made reference image #
#TODO: ref image registration is superfluous? maybe a symlink would work?
registered_refimlist = register_images([refim], params)
# TODO : we need to add a header and WCS?
copy_wcs(ref_image_list[0].fullname, refimpath)
copy_wcs(ref_image_list[0].fullname, registered_refimlist[0].fullname)
return (refim)
def get_observation_list(filenamelist, params):
""" From a given list of filenames, make a list of images as
pyDIA Observation objects.
If user has specified a full path to the input image files,
use that full path. If not, then check if each input image
file exists as a trimmed version, and use that. If not, fall
back is to use the original untrimmed image.
"""
observationslist = []
for filename in filenamelist:
if filename.endswith('_trim.fits'):
ftrimname = os.path.basename(filename)
else:
ftrimname = os.path.basename(filename).replace('.fits', '_trim.fits')
trimfile = os.path.join(params.loc_trim, ftrimname)
imfile = os.path.join(params.loc_data, os.path.basename(filename))
for f in [filename, trimfile, imfile]:
if os.path.exists(f):
g = DS.Observation(f, params)
observationslist.append(g)
break
return(observationslist)
def do_photometry(params,
extname='newflux',
star_file='star_positions',
psf_file='psf.fits',
star_positions=None,
reference_image='ref.fits'):
#
# Determine our list of files
#
all_files = os.listdir(params.loc_data)
all_files.sort()
files = []
for f in all_files:
if fnmatch.fnmatch(f, params.name_pattern):
g = DS.Observation(params.loc_data + os.path.sep + f, params)
if g.fw > 0.0:
files.append(g)
ref = DS.Observation(params.loc_output + os.path.sep + reference_image,
params)
ref.register(ref, params)
#
# Detect stars and compute the PSF if necessary
#
psf_file = params.loc_output + os.path.sep + psf_file
star_file = params.loc_output + os.path.sep + star_file
print psf_file
print os.path.exists(psf_file)
print star_file
print os.path.exists(star_file)
if not (os.path.exists(psf_file)) or not (os.path.exists(star_file)):
stars = PH.compute_psf_image(params, ref, psf_image=psf_file)
if star_positions is None:
if os.path.exists(star_file):
star_positions = np.genfromtxt(star_file)[:, :2]
else:
star_positions = stars[:, 0:2]
#
# Group the stars by location
#
star_group_boundaries = None
detector_mean_positions_x = None
detector_mean_positions_y = None
star_sort_index,star_group_boundaries,detector_mean_positions_x,detector_mean_positions_y = \
PH.group_stars_ccd(params,star_positions,params.loc_output+os.path.sep+reference_image)
star_positions = star_positions[star_sort_index]
star_unsort_index = np.argsort(star_sort_index)
#
# Process the reference image
#
print 'Processing', reference_image
ref = DS.Observation(params.loc_output + os.path.sep + reference_image,
params)
#reg = Observation(params.loc_data+os.path.sep+
# params.registration_image,params)
mask, _ = IO.read_fits_file(params.loc_output + os.path.sep + 'mask_' +
reference_image)
variance, _ = IO.read_fits_file(params.loc_output + os.path.sep + 'var_' +
reference_image)
ref.mask = mask
ref.inv_variance = 1.0 / variance + (1 - mask)
ref.register(ref, params)
smask = IM.compute_saturated_pixel_mask(ref.image, params)
ref.inv_variance += (1 - (smask * mask)) * 1.e-12
ktable = params.loc_output + os.path.sep + 'k_' + os.path.basename(
reference_image)
kernelIndex, extendedBasis, c, params = IO.read_kernel_table(
ktable, params)
kernelRadius = np.max(kernelIndex[:, 0]) + 1
if np.sum(extendedBasis) > 0:
kernelRadius += 1
print 'kernelIndex', kernelIndex
print 'extendedBasis', extendedBasis
print 'coeffs', c
print 'kernelRadius', kernelRadius
print 'star_positions', star_positions.shape
phot_target, _ = IO.read_fits_file(params.loc_output + os.path.sep +
'clean_' + reference_image)
ref.flux, ref.dflux = CIF.photom_all_stars_simultaneous(
phot_target, ref.inv_variance, star_positions, psf_file, c,
kernelIndex, extendedBasis, kernelRadius, params,
star_group_boundaries, detector_mean_positions_x,
detector_mean_positions_y)
if isinstance(ref.flux, np.ndarray):
if not (params.use_GPU):
print 'ungrouping fluxes'
ref.flux = ref.flux[star_unsort_index].copy()
ref.dflux = ref.dflux[star_unsort_index].copy()
print ref.flux.shape, star_positions.shape
np.savetxt(
params.loc_output + os.path.sep + reference_image + '.' + extname,
np.vstack((ref.flux, ref.dflux)))
#
# Process difference images
#
for f in files:
if not (os.path.exists(params.loc_output + os.path.sep + f.name + '.' +
extname)):
print 'Processing', f.name
target = f.name
dtarget = params.loc_output + os.path.sep + 'd_' + os.path.basename(
target)
ntarget = params.loc_output + os.path.sep + 'n_' + os.path.basename(
target)
ztarget = params.loc_output + os.path.sep + 'z_' + os.path.basename(
target)
ktable = params.loc_output + os.path.sep + 'k_' + os.path.basename(
target)
if os.path.exists(dtarget) and os.path.exists(
ntarget) and os.path.exists(ktable):
norm, h = IO.read_fits_file(ntarget)
diff, h = IO.read_fits_file(dtarget)
mask, h = IO.read_fits_file(ztarget)
inv_var = (norm / diff)**2 + (1 - mask)
kernelIndex, extendedBasis, c, params = IO.read_kernel_table(
ktable, params)
kernelRadius = np.max(kernelIndex[:, 0]) + 1
if np.sum(extendedBasis) > 0:
kernelRadius += 1
print 'kernelIndex', kernelIndex
print 'extendedBasis', extendedBasis
print 'coeffs', c
print 'kernelRadius', kernelRadius
IO.write_image(diff,
params.loc_output + os.path.sep + 'diff1.fits')
diff = IM.undo_photometric_scale(diff, c, params.pdeg)
IO.write_image(diff,
params.loc_output + os.path.sep + 'diff2.fits')
IO.write_image(
inv_var, params.loc_output + os.path.sep + 'inv_var.fits')
IO.write_kernel_table(
params.loc_output + os.path.sep + 'ktable.fits',
kernelIndex, extendedBasis, c, params)
flux, dflux = CI.photom_all_stars(
diff, inv_var, star_positions, psf_file, c, kernelIndex,
extendedBasis, kernelRadius, params, star_group_boundaries,
detector_mean_positions_x, detector_mean_positions_y)
print 'flux[100:110]:'
print flux[100:110]
if isinstance(flux, np.ndarray):
if not (params.use_GPU):
print 'ungrouping fluxes'
flux = flux[star_unsort_index].copy()
dflux = dflux[star_unsort_index].copy()
print 'unsort flux[100:110]:'
print flux[100:110]
np.savetxt(
params.loc_output + os.path.sep + f.name + '.' +
extname,
np.vstack((flux, dflux)).T)
sys.exit(0)
def imsub_all_fits(params, reference='ref.fits'):
#
# Create the output directory if it doesn't exist
#
if not (os.path.exists(params.loc_output)):
os.mkdir(params.loc_output)
#
# The degree of spatial shape changes has to be at least as
# high as the degree of spatial photometric scale
#
if (params.sdeg < params.pdeg):
print 'Increasing params.sdeg to ', params.pdeg
params.sdeg = params.pdeg
#
# Print out the parameters for this run.
#
print 'Parameters:'
for par in dir(params):
print par, getattr(params, par)
print
#
# Determine our list of images
#
all_files = os.listdir(params.loc_data)
all_files.sort()
files = []
for f in all_files:
print 'file', f
if fnmatch.fnmatch(f, params.name_pattern):
g = DS.Observation(params.loc_data + os.path.sep + f, params)
del g.data
del g.mask
print 'fw', g.fw
if g.fw > 0.0:
files.append(g)
print g.name, 'accepted'
if len(files) < 3:
print 'Only', len(files), 'files found matching', params.name_pattern
print 'Exiting'
sys.exit(0)
#
# Have we specified a registration template?
#
if params.registration_image:
reg = DS.Observation(params.registration_image, params)
else:
reg = DS.EmptyBase()
reg.fw = 999.0
for f in files:
if (f.fw < reg.fw) and (f.fw > params.reference_min_seeing) and (
f.sky < params.registration_max_background):
reg = f
print 'Registration image:', reg.name
#
# Register images
#
print 'Registering images'
files_copy = [f for f in files]
for f in files:
print f.name
if f == reg:
f.image = f.data
rf = params.loc_output + os.path.sep + 'r_' + f.name
IO.write_image(f.image, rf)
else:
if not f.register(reg, params):
files_copy.remove(f)
# delete image arrays to save memory
del f.image
del f.mask
del f.inv_variance
del reg.data
del reg.image
del reg.mask
del reg.inv_variance
files = files_copy
#
# Write image names and dates to a file
#
if params.image_list_file:
try:
with open(params.loc_output + os.path.sep + params.image_list_file,
'w') as fid:
for f in files:
date = None
if params.datekey:
date = IO.get_date(
params.loc_data + os.path.sep + f.name,
key=params.datekey) - 2450000
if date:
fid.write(f.name + ' %10.5f\n' % date)
else:
fid.write(f.name)
except:
raise
#
# Make the photometric reference image if we don't have it.
# Find stamp positions if required.
#
if not (os.path.exists(params.loc_output + os.path.sep + reference)):
print 'Reg = ', reg.name
stamp_positions = make_reference(files,
reg,
params,
reference_image=reference)
ref = DS.Observation(params.loc_output + os.path.sep + reference,
params)
mask, _ = IO.read_fits_file(params.loc_output + os.path.sep + 'mask_' +
reference)
variance, _ = IO.read_fits_file(params.loc_output + os.path.sep +
'var_' + reference)
ref.mask = mask
ref.inv_variance = 1.0 / variance
ref.register(reg, params)
else:
ref = DS.Observation(params.loc_output + os.path.sep + reference,
params)
if os.path.exists(params.loc_output + os.path.sep + 'mask_' +
reference):
mask, _ = IO.read_fits_file(params.loc_output + os.path.sep +
'mask_' + reference)
else:
mask = np.ones_like(ref.data)
ref.mask = mask
ref.register(reg, params)
stamp_positions = None
if params.use_stamps:
stamp_file = params.loc_output + os.path.sep + 'stamp_positions'
if os.path.exists(stamp_file):
stamp_positions = np.genfromtxt(stamp_file)
else:
stars = PF.choose_stamps(ref, params)
stamp_positions = stars[:, 0:2]
np.savetxt(stamp_file, stamp_positions)
pm = params.pixel_max
params.pixel_max *= 0.9
ref.mask *= IM.compute_saturated_pixel_mask(ref.image, params)
params.pixel_max = pm
ref.blur = IM.boxcar_blur(ref.image)
if params.mask_cluster:
ref.mask *= IM.mask_cluster(ref.image, ref.mask, params)
#
# Detect stars and compute the PSF if we are doing photometry
#
star_positions = None
sky = 0.0
if params.do_photometry:
star_file = params.loc_output + os.path.sep + 'star_positions'
psf_file = params.loc_output + os.path.sep + 'psf.fits'
if not (os.path.exists(psf_file)) or not (os.path.exists(star_file)):
stars = PH.compute_psf_image(params, ref, psf_image=psf_file)
star_positions = stars[:, 0:2]
star_sky = stars[:, 4]
if os.path.exists(star_file):
star_positions = np.genfromtxt(star_file)
star_sky = star_positions[:, 0] * 0.0
else:
np.savetxt(star_file, star_positions)
print 'sky =', sky
#
# If we have pre-determined star positions
#
if params.star_file:
stars = np.genfromtxt(params.star_file)
star_positions = stars[:, 1:3]
if params.star_reference_image:
star_ref, h = IO.read_fits_file(params.star_reference_image)
offset, _, _ = register_translation(star_ref, ref.image, 1000)
dy, dx = offset
#dy, dx = IM.positional_shift(ref.image,star_ref)
print 'position shift =', dx, dy
star_positions[:, 0] -= dx
star_positions[:, 1] -= dy
np.savetxt(star_file, star_positions)
#
# If we are using a CPU, group the stars by location
#
print 'Group_check'
print 'params.do_photometry', params.do_photometry
print 'params.use_GPU', params.use_GPU
if params.do_photometry:
star_group_boundaries = None
detector_mean_positions_x = None
detector_mean_positions_y = None
star_unsort_index = None
star_sort_index,star_group_boundaries,detector_mean_positions_x,detector_mean_positions_y = \
PH.group_stars_ccd(params,star_positions,params.loc_output+os.path.sep+reference)
star_positions = star_positions[star_sort_index]
star_sky = star_sky[star_sort_index]
star_unsort_index = np.argsort(star_sort_index)
#
# Do photometry of the reference image
#
if params.do_photometry:
ref_flux_file = params.loc_output + os.path.sep + 'ref.flux'
if not (os.path.exists(ref_flux_file)):
result = difference_image(
ref,
ref,
params,
stamp_positions=stamp_positions,
psf_image=psf_file,
star_positions=star_positions,
star_group_boundaries=star_group_boundaries,
detector_mean_positions_x=detector_mean_positions_x,
detector_mean_positions_y=detector_mean_positions_y,
star_sky=star_sky)
if isinstance(result.flux, np.ndarray):
print 'ungrouping fluxes'
result.flux = result.flux[star_unsort_index].copy()
result.dflux = result.dflux[star_unsort_index].copy()
np.savetxt(ref_flux_file,
np.vstack((result.flux, result.dflux)).T)
#
# Process images
#
if params.make_difference_images:
if not (params.use_GPU) and (params.n_parallel > 1):
pool = Pool(params.n_parallel)
pool.map(
process_image_helper,
itertools.izip(
files,
itertools.repeat(
(ref, params, stamp_positions, star_positions,
star_group_boundaries, star_unsort_index,
detector_mean_positions_x,
detector_mean_positions_y))))
else:
for f in files:
process_image(
f, (ref, params, stamp_positions, star_positions,
star_group_boundaries, star_unsort_index,
detector_mean_positions_x, detector_mean_positions_y))
return files
def do_photometry(params,
extname='newflux',
star_file='star_positions',
psf_file='psf.fits',
star_positions=None,
reference_image='ref.fits'):
#
# Determine our list of files
#
all_files = os.listdir(params.loc_data)
all_files.sort()
files = []
for f in all_files:
if fnmatch.fnmatch(f, params.name_pattern):
g = DS.Observation(params.loc_data + os.path.sep + f, params)
if g.fw > 0.0:
files.append(g)
ref = DS.Observation(params.loc_output + os.path.sep + reference_image,
params)
ref.register(ref, params)
#
# Detect stars and compute the PSF if necessary
#
if params.do_photometry:
psf_file = params.loc_output + os.path.sep + psf_file
if os.path.exists(params.star_file):
star_pos = np.genfromtxt(params.star_file)[:, 1:3]
if not (os.path.exists(psf_file)):
stars = PH.compute_psf_image(params, ref, psf_image=psf_file)
else:
if not (os.path.exists(star_file)):
stars = PH.compute_psf_image(params, ref, psf_image=psf_file)
star_pos = stars[:, 0:2]
np.savetxt(star_file, star_pos)
else:
star_pos = np.genfromtxt(star_file)
if not (os.path.exists(psf_file)):
stars = PH.compute_psf_image(params,
ref,
psf_image=psf_file)
#
# Have we been passed an array of star positions?
#
if star_positions == None:
star_positions = star_pos
#
# If we are using a CPU, group the stars by location
#
star_group_boundaries = None
detector_mean_positions_x = None
detector_mean_positions_y = None
if not (params.use_GPU):
star_sort_index, star_group_boundaries, detector_mean_positions_x, detector_mean_positions_y = PH.group_stars_ccd(
params, star_positions,
params.loc_output + os.path.sep + reference_image)
star_positions = star_positions[star_sort_index]
star_unsort_index = np.argsort(star_sort_index)
#
# Process the reference image
#
print('Processing', reference_image)
ref = DS.Observation(params.loc_output + os.path.sep + reference_image,
params)
# reg = Observation(params.loc_data+os.path.sep+
# params.registration_image,params)
ref.register(ref, params)
smask = IM.compute_saturated_pixel_mask(ref.image, 6, params)
ref.inv_variance += 1 - smask
ktable = params.loc_output + os.path.sep + 'k_' + os.path.basename(
reference_image)
kernelIndex, extendedBasis, c, params = IO.read_kernel_table(
ktable, params)
kernelRadius = np.max(kernelIndex[:, 0]) + 1
if np.sum(extendedBasis) > 0:
kernelRadius += 1
print('kernelIndex', kernelIndex)
print('extendedBasis', extendedBasis)
print('coeffs', c)
print('kernelRadius', kernelRadius)
phot_target = ref.image
ref.flux, ref.dflux = CI.photom_all_stars(
phot_target, ref.inv_variance, star_positions, psf_file, c,
kernelIndex, extendedBasis, kernelRadius, params,
star_group_boundaries, detector_mean_positions_x,
detector_mean_positions_y)
if isinstance(ref.flux, np.ndarray):
if not (params.use_GPU):
print('ungrouping fluxes')
ref.flux = ref.flux[star_unsort_index].copy()
ref.dflux = ref.dflux[star_unsort_index].copy()
np.savetxt(
params.loc_output + os.path.sep + reference_image + '.' + extname,
np.vstack((ref.flux, ref.dflux)).T)
#
# Process difference images
#
for f in files:
if not (os.path.exists(params.loc_output + os.path.sep + f.name + '.' +
extname)):
print('Processing', f.name)
target = f.name
dtarget = params.loc_output + os.path.sep + 'd_' + os.path.basename(
target)
ntarget = params.loc_output + os.path.sep + 'n_' + os.path.basename(
target)
ztarget = params.loc_output + os.path.sep + 'z_' + os.path.basename(
target)
ktable = params.loc_output + os.path.sep + 'k_' + os.path.basename(
target)
if os.path.exists(dtarget) and os.path.exists(
ntarget) and os.path.exists(ktable):
norm, h = IO.read_fits_file(ntarget)
diff, h = IO.read_fits_file(dtarget)
mask, h = IO.read_fits_file(ztarget)
inv_var = (norm / diff)**2 + (1 - mask)
kernelIndex, extendedBasis, c, params = IO.read_kernel_table(
ktable, params)
kernelRadius = np.max(kernelIndex[:, 0]) + 1
if np.sum(extendedBasis) > 0:
kernelRadius += 1
print('kernelIndex', kernelIndex)
print('extendedBasis', extendedBasis)
print('coeffs', c)
print('kernelRadius', kernelRadius)
diff = IM.undo_photometric_scale(diff, c, params.pdeg)
flux, dflux = PH.photom_all_stars(
diff, inv_var, star_positions, psf_file, c, kernelIndex,
extendedBasis, kernelRadius, params, star_group_boundaries,
detector_mean_positions_x, detector_mean_positions_y)
if isinstance(flux, np.ndarray):
if not (params.use_GPU):
print('ungrouping fluxes')
flux = flux[star_unsort_index].copy()
dflux = dflux[star_unsort_index].copy()
np.savetxt(
params.loc_output + os.path.sep + f.name + '.' +
extname,
np.vstack((flux, dflux)).T)
def do_everything(params=None):
if params is None:
params = set_default_parameters()
# Create the output directory if it doesn't exist
if not (os.path.exists(params.loc_output)):
os.mkdir(params.loc_output)
# The degree of spatial shape changes has to be at least as
# high as the degree of spatial photometric scale
if (params.sdeg < params.pdeg):
print('Increasing params.sdeg to ', params.pdeg)
params.sdeg = params.pdeg
# Print out the parameters for this run.
print('Parameters:')
for par in dir(params):
print(par, getattr(params, par))
print('Determining list of input images')
input_file_basenames = os.listdir(params.loc_input)
input_file_paths = []
for f in input_file_basenames:
if fnmatch.fnmatch(f, params.name_pattern):
input_file_paths.append(os.path.join(params.loc_input,f))
if params.dospintrim:
print("Spinning and trimming input images")
if not params.wcs_ref_image:
refimname = params.ref_image
refimpath = os.path.join(params.loc_output, refimname)
if os.path.exists(refimpath):
params.wcs_ref_image = refimpath
if not params.wcs_ref_image:
params.wcs_ref_image = input_file_paths[0]
spin_and_trim(input_file_paths, params.wcs_ref_image, params.trimfrac)
if params.dorefim:
print("Making reference image")
refim = make_ref_image(params)
else:
refimpath = os.path.join(params.loc_output, params.ref_image)
refim = DS.Observation(refimpath, params)
trim_file_basenames = os.listdir(params.loc_trim)
trim_file_paths = []
# read in a list of input images for creating the ref image
ref_input_filenames = []
if os.path.exists(params.ref_image_list):
fin = open(params.ref_image_list, 'r')
ref_input_filenames = [os.path.basename(f.strip())
for f in fin.readlines()]
fin.close()
for f in trim_file_basenames:
if fnmatch.fnmatch(f, params.name_pattern):
if f not in ref_input_filenames:
trim_file_paths.append(os.path.join(params.loc_trim,f))
print("Trimmed files to subtract: %s"%str(trim_file_paths))
if params.dodiffs:
print("Making diff images")
make_diff_images(trim_file_paths, refim, params)
return
def make_diff_images(filenamelist, refim, params):
""" make a diff image for each file in filenamelist: file - refim.
filenamelist : list of filenames for 'target' images
refim : reference image, either a filename or a DIA Observation object
params : DIA parameters object
"""
star_group_boundaries = None
detector_mean_positions_x = None
detector_mean_positions_y = None
star_unsort_index = None
star_positions = None
stamp_positions = None
sky = 0.0
if isinstance(refim, str) and os.path.exists(refim):
refim = DS.Observation(refim, params)
# TODO: investigate what is really being done here:
# Apply saturation mask and boxcar blurring to reference image
mask, _ = IO.read_fits_file(
params.loc_output + os.path.sep + 'mask_' + refim.name)
refim.mask = mask
pm = params.pixel_max
params.pixel_max *= 0.9
refim.mask *= IM.compute_saturated_pixel_mask(refim.image, 4, params)
params.pixel_max = pm
refim.blur = IM.boxcar_blur(refim.image)
if params.mask_cluster:
refim.mask *= IM.mask_cluster(refim.image, refim.mask, params)
# For each given filename, get a pyDIA observation object
image_list = get_observation_list(filenamelist, params)
# Register the images, using the ref image as the registration template,
# unless the user has specified otherwise
if not params.registration_image:
params.registration_image = refim.fullname
registered_image_list = register_images(image_list, params)
# make diff images: im - ref
for im in registered_image_list:
result = DIA.difference_image(
refim, im, params,
stamp_positions=stamp_positions,
psf_image=params.loc_output + os.path.sep + 'psf.fits',
star_positions=star_positions,
star_group_boundaries=star_group_boundaries,
detector_mean_positions_x=detector_mean_positions_x,
detector_mean_positions_y=detector_mean_positions_y)
del im.image
del im.mask
del im.inv_variance
hdr = fits.getheader(im.fullname)
# TODO : use astropy fits to propagate header with WCS from parent image
# Save output images to files
if isinstance(result.diff, np.ndarray):
IO.write_image(result.diff,
params.loc_output + os.path.sep + 'd_' + im.name,
header=hdr)