org.gridfour.lsop

Class LsEncoder08

java.lang.Object

org.gridfour.lsop.LsEncoder08

All Implemented Interfaces:

ICompressionEncoder

public class LsEncoder08
extends Object
implements ICompressionEncoder

Provides methods and data elements used to encode raster data to be compressed using the LSOP format based on the methods of Lewis and Smith's Optimal Predictor with 8 coefficients

The LS decoder and encoder are separated into separate packages and separate modules in order to manage code dependencies. The encoding process requires solving a 9-variable linear system. Doing so requires the use of a 3rd party Java library, so an implementation that uses the LS format introduces an additional dependency to the code base. But the decoding process does not use any operations that would require an external dependency. Thus the decoder is specified as part of the Gridfour core module, but the encoder is not.

Constructor Summary

Constructors

Constructor and Description
LsEncoder08()

Method Summary

Modifier and Type	Method and Description
byte[]	encode(int codecIndex, int nRows, int nCols, int[] values) Encodes the specified tile data in a compressed form.
byte[]	encodeFloats(int codecIndex, int nRows, int nCols, float[] values) Encodes the specified tile data in a compressed form.
boolean	implementsFloatingPointEncoding() Indicates whether the implementation can encode floating-point values
boolean	implementsIntegerEncoding() Indicates whether the implementation can encode integral data types

Methods inherited from class java.lang.Object

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

Constructor Detail

LsEncoder08

public LsEncoder08()

Method Detail

encode

public byte[] encode(int codecIndex,
                     int nRows,
                     int nCols,
                     int[] values)

Description copied from interface: ICompressionEncoder

Encodes the specified tile data in a compressed form.

Specified by:

encode in interface ICompressionEncoder

Parameters:

codecIndex - the index assigned by the application to associate a codec with an entry in the raster file.

nRows - a value of 1 or greater giving the number of rows in the tile

nCols - a value of 1 or greater giving the number of columns in the tile

values - the values of the tile in row-major order

Returns:

if successful, an array of bytes of length greater than 1; if unsuccessful, a null.

encodeFloats

public byte[] encodeFloats(int codecIndex,
                           int nRows,
                           int nCols,
                           float[] values)

Description copied from interface: ICompressionEncoder

Encodes the specified tile data in a compressed form.

Specified by:

encodeFloats in interface ICompressionEncoder

Parameters:

codecIndex - the index assigned by the application to associate a codec with an entry in the raster file.

nRows - a value of 1 or greater giving the number of rows in the tile

nCols - a value of 1 or greater giving the number of columns in the tile

values - the values of the tile in row-major order

Returns:

if successful, an array of bytes of length greater than 1; if unsuccessful, a null.

implementsFloatingPointEncoding

public boolean implementsFloatingPointEncoding()

Description copied from interface: ICompressionEncoder

Indicates whether the implementation can encode floating-point values

Specified by:

implementsFloatingPointEncoding in interface ICompressionEncoder

Returns:

true if direct encoding of floats is supported, otherwise false.

implementsIntegerEncoding

public boolean implementsIntegerEncoding()

Description copied from interface: ICompressionEncoder

Indicates whether the implementation can encode integral data types

Specified by:

implementsIntegerEncoding in interface ICompressionEncoder

Returns:

true if the encoding of integral data types is supported, otherwise false.