diff options
Diffstat (limited to 'astro/fits')
| -rwxr-xr-x | astro/fits/fitscube.py | 49 |
1 files changed, 44 insertions, 5 deletions
diff --git a/astro/fits/fitscube.py b/astro/fits/fitscube.py index df72351..3d2d4d0 100755 --- a/astro/fits/fitscube.py +++ b/astro/fits/fitscube.py @@ -39,14 +39,13 @@ class FITSCube: Create a FITS cube from input image slices. """ nslice = len(slices) - with fits.open(slices[0]) as f: - image = f[0].data - header = f[0].header + header, image = self.open_image(slices[0]) shape = (nslice, ) + image.shape data = np.zeros(shape, dtype=image.dtype) for i, s in enumerate(slices): - print("Adding image slice: %s ..." % s) - data[i, :, :] = fits.open(s)[0].data + print("[%d/%d] Adding image slice: %s ..." % (i, nslice, s)) + hdr, img = self.open_image(s) + data[i, :, :] = img self.data = data wcs = self.make_wcs(header, zbegin=zbegin, zstep=zstep) self.header = header.copy(strip=True) @@ -54,6 +53,46 @@ class FITSCube: print("Created FITS cube of dimensions: %dx%dx%d" % (self.width, self.height, self.nslice)) + @staticmethod + def open_image(infile): + """ + Open the slice image and return its header and 2D image data. + + NOTE + ---- + The input slice image may have following dimensions: + * NAXIS=2: [Y, X] + * NAXIS=3: [FREQ=1, Y, X] + * NAXIS=4: [FREQ=1, STOKES=1, Y, X] + + NOTE + ---- + Only open slice image that has only ONE frequency and ONE Stokes + parameter. + + Returns + ------- + header : `~astropy.io.fits.Header` + image : 2D `~numpy.ndarray` + The 2D [Y, X] image part of the slice image. + """ + with fits.open(infile) as f: + header = f[0].header + data = f[0].data + if data.ndim == 2: + # NAXIS=2: [Y, X] + image = data + elif data.ndim == 3 and data.shape[0] == 1: + # NAXIS=3: [FREQ=1, Y, X] + image = data[0, :, :] + elif data.ndim == 4 and data.shape[0] == 1 and data.shape[1] == 1: + # NAXIS=4: [FREQ=1, STOKES=1, Y, X] + image = data[0, 0, :, :] + else: + raise ValueError("Slice '{0}' has invalid dimensions: {1}".format( + infile, data.shape)) + return (header, image) + def make_wcs(self, header, zbegin, zstep): w = WCS(naxis=3) w.wcs.ctype = ["pixel", "pixel", "pixel"] |