FitsCompressionOptions

pydantic model lsst.images.fits.FitsCompressionOptions

Configuration options for FITS compression.

Parameters:

data (Any)

Fields:

• algorithm (lsst.images.fits._common.FitsCompressionAlgorithm)

• quantization (lsst.images.fits._common.FitsQuantizationOptions | None)

• tile_shape (tuple[int, ...] | None)

field algorithm: FitsCompressionAlgorithm = FitsCompressionAlgorithm.GZIP_2

Compression algorithm to use.

field quantization: FitsQuantizationOptions | None = None

Quantization to apply before compression, if any.

field tile_shape: tuple[int, ...] | None = None

Shape (..., y, x) of independently compressed tiles.

The default of None leaves the tile shape up to the tile_shape argument to add_array.

make_hdu(data, name)

Make an astropy.io.fits.CompImageHDU object from these options.

Parameters:

• data (ndarray) – Pixel data to store in the HDU.

• name (str) – EXTNAME of the HDU.

Return type:

CompImageHDU

DEFAULT: ClassVar[FitsCompressionOptions | None] = FitsCompressionOptions(algorithm=<FitsCompressionAlgorithm.GZIP_2: 'GZIP_2'>, tile_shape=None, quantization=None)

Default compression options (lossless GZIP_2).

LOSSY: ClassVar[FitsCompressionOptions] = FitsCompressionOptions(algorithm=<FitsCompressionAlgorithm.RICE_1: 'RICE_1'>, tile_shape=None, quantization=FitsQuantizationOptions(dither=<FitsDitherAlgorithm.SUBTRACTIVE_DITHER_2: 'SUBTRACTIVE_DITHER_2'>, level=16.0, seed=None))

Default lossy compression options.