diff options
| -rwxr-xr-x | astro/fits/fitscube.py | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/astro/fits/fitscube.py b/astro/fits/fitscube.py index a2ec032..fbdaaf8 100755 --- a/astro/fits/fitscube.py +++ b/astro/fits/fitscube.py @@ -152,6 +152,13 @@ class FITSCube: self.zstep]) return w + def keyword(self, key, value=None, comment=None): + header = self.header + if value is None: + return header[key] + else: + header[key] = (value, comment) + def write(self, outfile, clobber=False): header = self.header header.extend(self.wcs.to_header(), update=True) @@ -220,6 +227,24 @@ class FITSCube: gain = np.asarray(gain) self.data *= gain[:, np.newaxis, np.newaxis] + def pool(self, blocksize, func=np.mean): + """ + Down-sampling the images by pooling + """ + try: + from skimage.measure import block_reduce + except ImportError: + print("scikit-image not installed") + raise + + self.data = block_reduce(self.data, + block_size=(1, blocksize, blocksize), + func=func) + self.keyword(key="POOL_BS", value=blocksize, + comment="down-sampling block size") + self.keyword(key="POOL_FUN", value=func.__name__, + comment="down-sampling function/method") + @property def unit(self): """ @@ -480,6 +505,27 @@ def cmd_corrupt(args): print("Saved corruption information to file: %s" % infofile) +def cmd_pool(args): + """ + Sub-command: "pool", down-sample image cube along the spatial dimension. + """ + if not args.clobber and os.path.exists(args.outfile): + raise OSError("output file already exists: %s" % args.outfile) + + cube = FITSCube(args.infile) + print("Data cube unit: %s" % cube.unit) + print("Image/slice size: %dx%d" % (cube.width, cube.height)) + print("Number of slices: %d" % cube.nslice) + + print("Pooling image cube ...") + print("block size: %d, method: %s" % (args.blocksize, args.method)) + cube.pool(blocksize=args.blocksize, func=getattr(np, args.method)) + print("Pooled image/slice size: %dx%d" % (cube.width, cube.height)) + print("Saving pooled FITS cube ...") + cube.write(args.outfile, clobber=args.clobber) + print("Pooled FITS cube wrote to: %s" % args.outfile) + + def main(): parser = argparse.ArgumentParser( description="FITS image cube manipulation tool") @@ -631,6 +677,25 @@ def main(): "channel/slice to a text file") parser_crp.set_defaults(func=cmd_corrupt) + # sub-command: "pool" + parser_pool = subparsers.add_parser( + "pool", + help="down-sample image cube along the spatial dimensions") + parser_pool.add_argument("-C", "--clobber", dest="clobber", + action="store_true", + help="overwrite existing output file") + parser_pool.add_argument("-i", "--infile", required=True, + help="input FITS cube filename") + parser_pool.add_argument("-o", "--outfile", required=True, + help="output pooled FITS cube") + parser_pool.add_argument("-n", "--block-size", dest="blocksize", + type=int, required=True, + help="down-sampling block size (i.e., factor)") + parser_pool.add_argument("-m", "--method", default="mean", + choices=["mean", "min", "max"], + help="down-sampling method (default: mean)") + parser_pool.set_defaults(func=cmd_pool) + args = parser.parse_args() args.func(args) |