JPEGCompressor Class Reference

Wrapper class to the IJG JPEG library. More...

#include <JPEGCompressor.h>

Inheritance diagram for JPEGCompressor:

Public Member Functions
	JPEGCompressor (int quality)
	Constructor.
void	setQuality (int factor)
	Set the compression quality.
int	getQuality () const
	Get the current quality level.
void	InitCompression (const RawTile &rawtile, unsigned int strip_height)
	Initialise strip based compression.
unsigned int	CompressStrip (unsigned char *s, unsigned char *o, unsigned int tile_height)
	Compress a strip of image data.
unsigned int	Finish (unsigned char *output)
	Finish the strip based compression and free memory.
unsigned int	Compress (RawTile &t)
	Compress an entire buffer of image data at once in one command.
unsigned int	getHeaderSize () const
	Return the JPEG header size.
unsigned char *	getHeader ()
	Return a pointer to the header itself.
const char *	getMimeType () const
	Return the JPEG mime type.
const char *	getSuffix () const
	Return the image filename suffix.
CompressionType	getCompressionType () const
	Get compression type.
Public Member Functions inherited from Compressor
	Compressor (int compressionLevel)
	Constructor.
int	getQuality () const
	Get the current quality level.
void	setResolution (float x, float y, int units)
	Set the physical output resolution.
void	setICCProfile (const std::string &profile)
	Set the ICC profile.
void	setXMPMetadata (const std::string &x)
	Set XMP metadata.
virtual unsigned int	getHeaderSize () const
	Return the image header size.
virtual unsigned char *	getHeader ()
	Return a pointer to the image header itself.
virtual void	InitCompression (const RawTile &rawtile, unsigned int strip_height)
	Initialise strip based compression.
virtual unsigned int	CompressStrip (unsigned char *s, unsigned char *o, unsigned int tile_height)
	Compress a strip of image data.
virtual unsigned int	Finish (unsigned char *output)
	Finish the strip based compression and free memory.
virtual unsigned int	Compress (RawTile &t)
	Compress an entire buffer of image data at once in one command.
virtual void	addXMPMetadata (const std::string &m)
	Add metadata to the image header.
virtual const char *	getMimeType () const
	Get mime type.
virtual const char *	getSuffix () const
	Get file suffix.
virtual CompressionType	getCompressionType () const
	Get compression type.

Additional Inherited Members
virtual void	writeICCProfile ()
	Write ICC profile.
virtual void	writeXMPMetadata ()
	Write XMP metadata.
Protected Attributes inherited from Compressor
int	Q
	Quality or compression level for all image types.
unsigned char *	header
	Pointer to the header data for the output image.
unsigned int	header_size
	Size of the header data.
float	dpi_x
	Physical resolution for X and Y directions.
float	dpi_y
int	dpi_units
	Resolution units.
std::string	icc
	ICC Profile.
std::string	xmp
	XMP metadata.

Detailed Description

Wrapper class to the IJG JPEG library.

Constructor & Destructor Documentation

JPEGCompressor()

JPEGCompressor::JPEGCompressor ( int  quality )

inline

Constructor.

Parameters

quality

JPEG Quality factor (0-100)

Member Function Documentation

Compress()

unsigned int JPEGCompressor::Compress ( RawTile &  t )

virtual

Compress an entire buffer of image data at once in one command.

Parameters

t	tile of image data

Reimplemented from Compressor.

CompressStrip()

unsigned int JPEGCompressor::CompressStrip ( unsigned char *  s, unsigned char *  o, unsigned int  tile_height  )

virtual

Compress a strip of image data.

Parameters

s	source image data
o	output buffer
tile_height	pixel height of the tile we are compressing

Reimplemented from Compressor.

Finish()

unsigned int JPEGCompressor::Finish ( unsigned char *  output )

virtual

Finish the strip based compression and free memory.

Parameters

output

output buffer

Returns

size of output generated

Reimplemented from Compressor.

getCompressionType()

CompressionType JPEGCompressor::getCompressionType ( ) const

inlinevirtual

Get compression type.

Reimplemented from Compressor.

getHeader()

unsigned char * JPEGCompressor::getHeader ( )

inlinevirtual

Return a pointer to the header itself.

Reimplemented from Compressor.

References Compressor::header.

getHeaderSize()

unsigned int JPEGCompressor::getHeaderSize ( ) const

inlinevirtual

Return the JPEG header size.

Reimplemented from Compressor.

References Compressor::header_size.

getMimeType()

const char * JPEGCompressor::getMimeType ( ) const

inlinevirtual

Return the JPEG mime type.

Reimplemented from Compressor.

getSuffix()

const char * JPEGCompressor::getSuffix ( ) const

inlinevirtual

Return the image filename suffix.

Reimplemented from Compressor.

InitCompression()

void JPEGCompressor::InitCompression ( const RawTile &  rawtile, unsigned int  strip_height  )

virtual

Initialise strip based compression.

If we are doing a strip based encoding, we need to first initialise with InitCompression, then compress a single strip at a time using CompressStrip and finally clean up using Finish

Parameters

rawtile	tile containing the image to be compressed
strip_height	pixel height of the strip we want to compress

Returns

header size

Reimplemented from Compressor.

setQuality()

void JPEGCompressor::setQuality ( int  factor )

inline

Set the compression quality.

Parameters

factor

Quality factor (0-100)

References Compressor::Q.

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

• JPEGCompressor.h