def xdf_sky_stamp(imroot,
psfname,
world,
wsize,
base=base,
fwhm=3.0,
background=0.0,
filtername="H"):
"""Make a stamp with celestial coordinate information.
"""
from astropy.coordinates import SkyCoord
from astropy import units as u
impath = os.path.join(base, "data", "images")
psfpath = os.path.join(base, "data", "psfs", "mixtures")
position = SkyCoord(world[0], world[1], unit="deg", frame="icrs")
size = wsize * u.arcsec
hdr = fits.getheader(os.path.join(impath, imroot + "sci.fits"))
sci = fits.getdata(os.path.join(impath, imroot + "sci.fits"))
wht = fits.getdata(os.path.join(impath, imroot + "wht.fits"))
wcs = WCS(hdr)
# note size should be (ny, nx)
flipped_size = (np.zeros(2) + np.array(wsize))[::-1] * u.arcsec
image = Cutout2D(sci, position, size, wcs=wcs)
weight = Cutout2D(wht, position, size, wcs=wcs)
im = np.ascontiguousarray(image.data)
ivar = np.ascontiguousarray(weight.data)
# -----------
# --- MAKE STAMP -------
# --- Add image and uncertainty data to Stamp, flipping axis order ----
stamp = PostageStamp()
stamp.pixel_values = np.array(im).T - background
stamp.ierr = np.sqrt(ivar).T
# Clean errors
bad = ~np.isfinite(stamp.ierr)
stamp.pixel_values[bad] = 0.0
stamp.ierr[bad] = 0.0
stamp.ierr = stamp.ierr.flatten()
stamp.nx, stamp.ny = stamp.pixel_values.shape
# note the inversion of x and y order in the meshgrid call here
stamp.ypix, stamp.xpix = np.meshgrid(np.arange(stamp.ny),
np.arange(stamp.nx))
# --- Add WCS info to Stamp ---
psize = np.array(stamp.pixel_values.shape)
stamp.crpix = np.floor(0.5 * psize)
stamp.crval = image.wcs.wcs_pix2world(stamp.crpix[None, :], 0)[0, :2]
CD = image.wcs.wcs.cd
W = np.eye(2)
W[0, 0] = np.cos(np.deg2rad(stamp.crval[-1]))
stamp.dpix_dsky = np.matmul(np.linalg.inv(CD), W)
stamp.scale = np.linalg.inv(CD * 3600.0)
stamp.CD = CD
stamp.W = W
try:
stamp.wcs = wcs
except:
pass
# --- Add the PSF ---
stamp.psf = pointspread.get_psf(os.path.join(psfpath, psfname), fwhm)
# --- Add extra information ---
stamp.full_header = dict(hdr)
if filtername is None:
stamp.filtername = stamp.full_header["FILTER"]
else:
stamp.filtername = filtername
return stamp
def xdf_pixel_stamp(imroot,
psfname,
center,
size,
fwhm=3.0,
background=0.0,
filtername="H",
base=base):
"""Make a stamp with pixel coordinate information.
"""
impath = os.path.join(base, "data", "images")
psfpath = os.path.join(base, "data", "psfs", "mixtures")
# Values used to produce the MMSE catalog
im, wght, rms, cutout, wcs = get_cutout(impath, imroot, mmse_position,
mmse_size)
# transpose to get x coordinate on the first axis
im = im.T
err = rms.T
CD = wcs.wcs.cd
# ---- Extract subarray -----
center = np.array(center)
# --- here is much mystery ---
size = np.array(size)
lo, hi = (center - 0.5 * size).astype(int), (center +
0.5 * size).astype(int)
xinds = slice(int(lo[0]), int(hi[0]))
yinds = slice(int(lo[1]), int(hi[1]))
crpix_stamp = np.floor(0.5 * size)
crval_stamp = crpix_stamp + lo
W = np.eye(2)
# --- MAKE STAMP -------
# --- Add image and uncertainty data to Stamp ----
stamp = PostageStamp()
stamp.pixel_values = im[xinds, yinds] - background
stamp.ierr = 1. / err[xinds, yinds]
bad = ~np.isfinite(stamp.ierr)
stamp.pixel_values[bad] = 0.0
stamp.ierr[bad] = 0.0
stamp.ierr = stamp.ierr.flatten()
stamp.nx, stamp.ny = stamp.pixel_values.shape
# note the inversion of x and y order in the meshgrid call here
stamp.ypix, stamp.xpix = np.meshgrid(np.arange(stamp.ny),
np.arange(stamp.nx))
# --- Add WCS info to Stamp ---
stamp.crpix = crpix_stamp
stamp.crval = crval_stamp
stamp.dpix_dsky = np.eye(2)
stamp.scale = np.linalg.inv(CD * 3600.0) # arcsec per pixel
stamp.pixcenter_in_full = center
stamp.lo = lo
stamp.CD = CD
stamp.W = W
# --- Add the PSF ---
stamp.psf = pointspread.get_psf(os.path.join(psfpath, psfname), fwhm)
stamp.filtername = filtername
return stamp
def make_real_stamp(imname,
center=(None, None),
size=(None, None),
center_type='pixels',
psfname=None,
fwhm=1.0,
psf_realization=2,
fix_header=False,
psf_ngauss=6,
psfcenter=104,
oversample=8):
"""Make a postage stamp around the given position using the given image name
"""
data = fits.getdata(imname)
hdr = fits.getheader(imname)
crpix = np.array([hdr['CRPIX1'], hdr['CRPIX2']])
crval = np.array([hdr['CRVAL1'], hdr['CRVAL2']])
CD = np.array([[hdr['CD1_1'], hdr['CD1_2']], [hdr['CD2_1'], hdr['CD2_2']]])
if fix_header:
# because hdr PC/CD/CDELT is sometimes wrong.
hdr["CDELT1"] = hdr['CD1_1'] / hdr["PC1_1"]
hdr["CDELT2"] = hdr['CD2_2'] / hdr["PC2_2"]
# Pull slices and transpose to get to an axis order that makes sense to me
# and corresponds with the wcs keyword ordering
im = data[0, :, :].T
err = data[1, :, :].T
# ---- Extract subarray -----
center = np.array(center)
# here we get the center coordinates in pixels (accounting for the transpose above)
if center_type == 'celestial':
world = center.copy()
ast = apy_wcs.WCS(hdr, naxis=2)
center = ast.wcs_world2pix(world[None, :], 0)[0, :2]
# --- here is much mystery ---
size = np.array(size)
lo, hi = (center - 0.5 * size).astype(int), (center +
0.5 * size).astype(int)
xinds = slice(int(lo[0]), int(hi[0]))
yinds = slice(int(lo[1]), int(hi[1]))
crpix_stamp = np.floor(0.5 * size)
crval_stamp = crpix_stamp + lo
W = np.eye(2)
if center_type == 'celestial':
crval_stamp = ast.wcs_pix2world(crval_stamp[None, :], 0)[0, :2]
W[0, 0] = np.cos(np.deg2rad(crval_stamp[-1]))
# -----------
# --- MAKE STAMP -------
# --- Add image and uncertainty data to Stamp ----
stamp = PostageStamp()
stamp.pixel_values = im[xinds, yinds]
stamp.ierr = 1. / err[xinds, yinds]
bad = ~np.isfinite(stamp.ierr)
stamp.pixel_values[bad] = 0.0
stamp.ierr[bad] = 0.0
stamp.ierr = stamp.ierr.flatten()
stamp.nx, stamp.ny = stamp.pixel_values.shape
# note the inversion of x and y order in the meshgrid call here
stamp.ypix, stamp.xpix = np.meshgrid(np.arange(stamp.ny),
np.arange(stamp.nx))
# --- Add WCS info to Stamp ---
stamp.crpix = crpix_stamp
stamp.crval = crval_stamp
stamp.dpix_dsky = np.matmul(np.linalg.inv(CD), W)
stamp.scale = np.linalg.inv(CD * 3600.0)
stamp.pixcenter_in_full = center
stamp.lo = lo
stamp.CD = CD
stamp.W = W
try:
stamp.wcs = ast
except:
pass
# --- Add the PSF ---
stamp.psf = get_psf(psfname, fwhm, psf_realization, psf_ngauss, oversample,
psfcenter)
# --- Add extra information ---
stamp.full_header = dict(hdr)
stamp.filtername = stamp.full_header["FILTER"]
return stamp