Source code for

Source type-dependencies.

Helioviewer JPEG2000 files have stretched images compared to the FITS data.

from astropy.visualization import LinearStretch

__author__ = "Jack Ireland"
__email__ = ""

__all__ = ['from_helioviewer_project', 'source_stretch']

[docs] def from_helioviewer_project(meta): """ Test determining if the given metadata contains Helioviewer Project sourced data. Parameters ---------- meta : `~astropy.utils.metadata.MetaData` The metadata to parse. Returns ------- If the data of the map comes from the Helioviewer Project, then True is returned. If not, False is returned. """ return 'helioviewer' in meta.keys()
[docs] def source_stretch(meta, fits_stretch): """ Assign the correct source-dependent image stretching function. Parameters ---------- meta : `~astropy.utils.metadata.MetaData` The metadata to parse. fits_stretch : `~astropy.visualization.BaseStretch` Image stretching function used when the source image data comes from a FITS file. Returns ------- An image stretching function appropriate to the image data source. """ if from_helioviewer_project(meta): # Helioviewer JPEG2000 files already have a stretched data values, so # just use a linear stretch. return LinearStretch() else: # Not a Helioviewer JPEG2000 file, so assume the data has not been # stretched and so use the FITS stretching as defined in the instrument # source. return fits_stretch