PLIO1

class astropy.io.fits.hdu.compressed._codecs.PLIO1(*, tilesize: int)

Bases: Codec

The FITS PLIO1 compression and decompression algorithm.

The IRAF PLIO (pixel list) algorithm was developed to store integer-valued image masks in a compressed form. Such masks often have large regions of constant value hence are highly compressible. The compression algorithm used is based on run-length encoding, with the ability to dynamically follow level changes in the image, allowing a 16-bit encoding to be used regardless of the image depth.

Attributes Summary

codec_id

Methods Summary

decode(buf)	Decompress buffer using the PLIO_1 algorithm.
encode(buf)	Compress the data in the buffer using the PLIO_1 algorithm.

Attributes Documentation

codec_id = 'FITS_PLIO1'

Methods Documentation

decode(buf)

Decompress buffer using the PLIO_1 algorithm.

Parameters:

bufbytes or numpy:array_like

The buffer to decompress.

Returns:

bufnp.ndarray

The decompressed buffer.

encode(buf)

Compress the data in the buffer using the PLIO_1 algorithm.

Parameters:

bufbytes or numpy:array_like

The buffer to compress.

Returns:

bytes

The compressed bytes.