Package nom.tam.fits.compression.algorithm.plio

Class PLIOCompress

java.lang.Object

nom.tam.fits.compression.algorithm.plio.PLIOCompress

Direct Known Subclasses:

PLIOCompress.BytePLIOCompressor, PLIOCompress.IntPLIOCompressor, PLIOCompress.ShortPLIOCompressor

public abstract class PLIOCompress
extends Object

(for internal use) The PLIO compression algorithm. The original decompression code was written by Doug Tody, NRAO and included (ported to c and adapted) in cfitsio by William Pence, NASA/GSFC. That code was then ported to Java by R. van Nieuwenhoven. Later it was massively refactored to harmonize the different compression algorithms and reduce the duplicate code pieces without obscuring the algorithm itself as good as possible.

Author:

Doug Tody, William Pence, Richard van Nieuwenhoven

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PLIOCompress.BytePLIOCompressor
static class	PLIOCompress.IntPLIOCompressor	Attention int values are limited to 24 bits!
static class	PLIOCompress.ShortPLIOCompressor

Constructor Summary

Constructors

Constructor	Description
PLIOCompress()

Method Summary

Modifier and Type	Method	Description
protected void	compress(ShortBuffer compressedData, int npix)	PL_P2L -- Convert a pixel tiledImageOperation to a line list.
protected int	decompress(ShortBuffer compressedData, int npix)	PL_L2PI -- Translate a PLIO line list into an integer pixel tiledImageOperation.
protected abstract int	nextPixel()
protected abstract void	put(int index, int pixel)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

PLIOCompress

public PLIOCompress()

Method Details

compress

protected void compress(ShortBuffer compressedData,
 int npix)

PL_P2L -- Convert a pixel tiledImageOperation to a line list. The length of the list is returned as the function value.

Parameters:

compressedData - encoded line list

npix - number of pixels to convert

decompress

protected int decompress(ShortBuffer compressedData,
 int npix)

PL_L2PI -- Translate a PLIO line list into an integer pixel tiledImageOperation. The number of pixels output (always npix) is returned as the function value.

Parameters:

compressedData - encoded line list

npix - number of pixels to convert

Returns:

number of pixels converted

nextPixel

protected abstract int nextPixel()

put

protected abstract void put(int index,
 int pixel)