SoJpegDataCompressor Class Reference

Jpeg data compression More...

#include <LDM/compressors/SoJpegDataCompressor.h>

Inheritance diagram for SoJpegDataCompressor:

Public Member Functions
	SoJpegDataCompressor ()
	Constructor.
virtual	~SoJpegDataCompressor ()
	Destructor.
virtual size_t	compress (void *src, size_t srcLen, const TileInfo &tileInfo)
	Compresses the given buffer into the internal buffer.
virtual size_t	uncompress (void *dest, size_t destLen, const TileInfo &tileInfo)
	Uncompresses data from the internal buffer to the given buffer.
virtual SbString	getCompressionFormatName () const
	Returns the name of the compression algorithm used by this class.
virtual bool	isLossless ()
	This compression is lossy.
Public Member Functions inherited from SoDataCompressor
	SoDataCompressor ()
	Constructor.
virtual	~SoDataCompressor ()
	Destructor.
virtual void	setCompressionLevel (size_t level)
	Sets the compression level.
virtual void *	allocateCompressedBuffer (size_t size)
	Allocates the internal buffer to hold the compressed data.
virtual void *	getCompressedBuffer ()
	Returns the compressed data.
virtual size_t	getCompressionLevel ()
	Returns the compression level.
Public Member Functions inherited from SoTypedObject
virtual SoType	getTypeId () const =0
	Returns the type identifier for a specific instance.
SbBool	isOfType (const SoType &type) const
	Returns TRUE if this object is of the type specified in type or is derived from that type.
template<typename TypedObjectClass >
SbBool	isOfType () const
	Returns TRUE if this object is of the type of class TypedObjectClass or is derived from that class.

Additional Inherited Members
Static Public Member Functions inherited from SoDataCompressor
static SoDataCompressor *	getAppropriateCompressor (const SbString &name)
	Create and return an instance of a compressor of the given type.
static SbStringList	getAvailableCompressors ()
	Return a list of all available compressors.
static size_t	crc32 (const void *buf, size_t len)
	Utility function to get the CRC32 of a buffer.
Static Public Member Functions inherited from SoTypedObject
static SoType	getClassTypeId ()
	Returns the type identifier for this class.

Detailed Description

Jpeg data compression

This class implements a compression scheme based on libjpeg. It is a lossy compression.

The setCompressionLevel method (SoDataCompressor or SoConverterParameters) accepts values between 0 and 100. 0 gives best compression but most loss of data. 100 gives minimum compression and minimum data alteration. Default is 85.

Limitations:

• JPEG compression can only be used on 8-bit data sets.

SEE ALSO

SoGzipDataCompressor, SoDataCompressor, SoConverterParameters

Definition at line 65 of file SoJpegDataCompressor.h.

Constructor & Destructor Documentation

SoJpegDataCompressor()

SoJpegDataCompressor::SoJpegDataCompressor

(

)

Constructor.

~SoJpegDataCompressor()

virtual SoJpegDataCompressor::~SoJpegDataCompressor ( )

virtual

Destructor.

Member Function Documentation

compress()

virtual size_t SoJpegDataCompressor::compress ( void *  src, size_t  srcLen, const TileInfo &  tileInfo  )

virtual

Compresses the given buffer into the internal buffer.

Parameters

src	a pointer to the data to compress.
srcLen	the size of the source buffer in bytes.
tileInfo	contains information about the tile being processed.

Returns

The size in bytes of the compressed buffer.

Implements SoDataCompressor.

getCompressionFormatName()

virtual SbString SoJpegDataCompressor::getCompressionFormatName ( ) const

inlinevirtual

Returns the name of the compression algorithm used by this class.

This is the name the user must pass to the "-c" option of the converter to use this compression ("jpeg" here).

Returns

An SbString containing "jpeg".

Implements SoDataCompressor.

Definition at line 103 of file SoJpegDataCompressor.h.

isLossless()

virtual bool SoJpegDataCompressor::isLossless ( )

inlinevirtual

This compression is lossy.

Returns

false, the compression is lossy.

Implements SoDataCompressor.

Definition at line 109 of file SoJpegDataCompressor.h.

uncompress()

virtual size_t SoJpegDataCompressor::uncompress ( void *  dest, size_t  destLen, const TileInfo &  tileInfo  )

virtual

Uncompresses data from the internal buffer to the given buffer.

Parameters

dest	a pointer to the destination buffer.
destLen	the size of the destination buffer in bytes.
tileInfo	contains information about the tile being processed.

Returns

The number of uncompressed bytes.

Implements SoDataCompressor.

---

The documentation for this class was generated from the following file:

• LDM/compressors/SoJpegDataCompressor.h