lsst.afw.display._write_fits Namespace Reference

Functions
None	_add_wcs (str wcs_name, PropertyList ps, int x0=0, int y0=0)
None	writeFitsImage (str|int|io.BytesIO file, lsst.afw.image.Image|lsst.afw.image.Mask data, lsst.afw.geom.SkyWcs|None wcs=None, str title="", PropertySet|None metadata=None)

Function Documentation

_add_wcs()

None lsst.afw.display._write_fits._add_wcs ( str wcs_name, PropertyList ps, int x0 = 0, int y0 = 0 )

protected

Definition at line 37 of file _write_fits.py.

def _add_wcs(wcs_name: str, ps: PropertyList, x0: int = 0, y0: int = 0) -> None:
    ps.setInt(f"CRVAL1{wcs_name}", x0, "(output) Column pixel of Reference Pixel")
    ps.setInt(f"CRVAL2{wcs_name}", y0, "(output) Row pixel of Reference Pixel")
    ps.setDouble(f"CRPIX1{wcs_name}", 1.0, "Column Pixel Coordinate of Reference")
    ps.setDouble(f"CRPIX2{wcs_name}", 1.0, "Row Pixel Coordinate of Reference")
    ps.setString(f"CTYPE1{wcs_name}", "LINEAR", "Type of projection")
    ps.setString(f"CTYPE1{wcs_name}", "LINEAR", "Type of projection")
    ps.setString(f"CUNIT1{wcs_name}", "PIXEL", "Column unit")
    ps.setString(f"CUNIT2{wcs_name}", "PIXEL", "Row unit")
 
 

writeFitsImage()

None lsst.afw.display._write_fits.writeFitsImage	(	str | int | io.BytesIO	file,
		lsst.afw.image.Image | lsst.afw.image.Mask	data,
		lsst.afw.geom.SkyWcs | None	wcs = None,
		str	title = "",
		PropertySet | None	metadata = None )

Write a simple FITS file with no extensions.

Parameters
----------
file : `str` or `int`
    Path to a file or a file descriptor.
data : `lsst.afw.Image` or `lsst.afw.Mask`
    Data to be displayed.
wcs : `lsst.afw.geom.SkyWcs` or `None`, optional
    WCS to be written to header to FITS file.
title : `str`, optional
    If defined, the value to be stored in the ``OBJECT`` header.
    Overrides any value found in ``metadata``.
metadata : `lsst.daf.base.PropertySet` or `None`, optional
    Additional information to be written to FITS header.

Definition at line 48 of file _write_fits.py.

) -> None:
    """Write a simple FITS file with no extensions.
 
    Parameters
    ----------
    file : `str` or `int`
        Path to a file or a file descriptor.
    data : `lsst.afw.Image` or `lsst.afw.Mask`
        Data to be displayed.
    wcs : `lsst.afw.geom.SkyWcs` or `None`, optional
        WCS to be written to header to FITS file.
    title : `str`, optional
        If defined, the value to be stored in the ``OBJECT`` header.
        Overrides any value found in ``metadata``.
    metadata : `lsst.daf.base.PropertySet` or `None`, optional
        Additional information to be written to FITS header.
    """
    ps = PropertyList()
 
    # Seed with the external metadata, stripping wcs keywords.
    if metadata:
        lsst.afw.geom.stripWcsMetadata(metadata)
        ps.update(metadata)
 
    # Write WcsB, so that pixel (0,0) is correctly labelled (but ignoring XY0)
    _add_wcs("B", ps)
 
    if not wcs:
        _add_wcs("", ps)  # Works around a ds9 bug that WCSA/B is ignored if no WCS is present.
    else:
        shift = Extent2D(-data.getX0(), -data.getY0())
        if wcs.hasFitsApproximation():
            wcs = wcs.getFitsApproximation()
        new_wcs = wcs.copyAtShiftedPixelOrigin(shift)
        wcs_metadata = new_wcs.getFitsMetadata()
        ps.update(wcs_metadata)
 
    if title:
        ps.set("OBJECT", title, "Image being displayed")
 
    if isinstance(file, str):
        data.writeFits(file, metadata=ps)
    else:
        mem = lsst.afw.fits.MemFileManager()
        data.writeFits(manager=mem, metadata=ps)
        if isinstance(file, int):
            # Duplicate to prevent a double close, assuming the caller
            # will close the file descriptor they passed in.
            with os.fdopen(os.dup(file), "wb") as fh:
                fh.write(mem.getData())
        elif isinstance(file, subprocess.Popen):
            file.communicate(input=mem.getData())
        else:
            # Try the write() method directly.
            file.write(mem.getData())