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.
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.
const char *	getMimeType () const
	Return the JPEG mime type.
const char *	getSuffix () const
	Return the image filename suffix.
ImageEncoding	getImageEncoding () const
	Get compression type.
void	injectMetadata (RawTile &r)
	Inject metadata into raw JPEG bitstream.
Public Member Functions inherited from Compressor
	Compressor (int compressionLevel)
	Constructor.
unsigned int	getHeaderSize () const
	Return the image header size.
unsigned char *	getHeader ()
	Return a pointer to the image header itself.
int	getQuality () const
	Get the current quality level.
bool	defaultQuality () const
	Check whether we are using the default or whether user has requested a specific quality level.
void	setResolution (float x, float y, int units)
	Set the physical output resolution.
void	embedICCProfile (const bool embed)
	Embed ICC profile.
void	embedXMPMetadata (const bool embed)
	Embed XMP metadata.
void	embedExifMetadata (const bool embed)
	Embed EXIF metadata.
void	setMetadata (const std::map< const std::string, const std::string > &metadata)
	Set general metadata.

Additional Inherited Members
Protected Member Functions inherited from Compressor
virtual void	writeMetadata ()
	Write metadata.
Protected Attributes inherited from Compressor
int	Q
	Quality or compression level for all image types.
bool	default_quality
	Whether compression level is default or has been set manually.
unsigned char *	header
	Pointer to the header data for the output image.
unsigned int	header_size
	Size of the header data.
int	dpi_units
	Physical resolution units: 0 for unknown, 1 for dots/inch or 2 for dots/cm.
float	dpi_x
	Physical resolution (pixels per physical unit) for X direction.
float	dpi_y
	Physical resolution (pixels per phyisical unit) in Y direction.
std::map< const std::string, const std::string >	metadata
	Metadata.
std::string	icc
	ICC Profile.
bool	embedICC
	Whether ICC profile should be embedded.
std::string	xmp
	XMP metadata.
bool	embedXMP
	Whether XMP metadata should be embedded.
std::string	exif
	EXIF metadata.
bool	embedEXIF
	Whether EXIF metadata should be embedded.

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.

References RawTile::bpc, RawTile::capacity, RawTile::channels, RawTile::compressionType, RawTile::data, RawTile::dataLength, Compressor::exif, RawTile::height, Compressor::icc, RawTile::memoryManaged, iip_destination_mgr::pub, Compressor::Q, RawTile::quality, iip_destination_mgr::source, iip_destination_mgr::source_size, iip_destination_mgr::strip_height, RawTile::width, iip_destination_mgr::written, and Compressor::xmp.

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.

References Compressor::header, Compressor::header_size, iip_destination_mgr::pub, iip_destination_mgr::source, and iip_destination_mgr::source_size.

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.

References iip_destination_mgr::pub, iip_destination_mgr::source, iip_destination_mgr::source_size, and iip_destination_mgr::strip_height.

getImageEncoding()

ImageEncoding JPEGCompressor::getImageEncoding ( ) const

inlinevirtual

Get compression type.

Reimplemented from Compressor.

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

Reimplemented from Compressor.

References RawTile::bpc, RawTile::channels, RawTile::compressionType, Compressor::exif, Compressor::header, Compressor::header_size, RawTile::height, Compressor::icc, iip_destination_mgr::pub, Compressor::Q, iip_destination_mgr::source, iip_destination_mgr::source_size, iip_destination_mgr::strip_height, RawTile::width, and Compressor::xmp.

Referenced by injectMetadata().

injectMetadata()

void JPEGCompressor::injectMetadata ( RawTile &  r )

virtual

Inject metadata into raw JPEG bitstream.

Parameters

r	image tile

Reimplemented from Compressor.

References RawTile::capacity, RawTile::data, RawTile::dataLength, Compressor::embedEXIF, Compressor::embedICC, Compressor::embedXMP, Compressor::exif, Compressor::getHeader(), Compressor::getHeaderSize(), Compressor::icc, InitCompression(), RawTile::memoryManaged, and Compressor::xmp.

setQuality()

void JPEGCompressor::setQuality ( int  factor )

inlinevirtual

Set the compression quality.

Parameters

factor

Quality factor (0-100)

Reimplemented from Compressor.

References Compressor::default_quality, and Compressor::Q.

Referenced by QLT::run().

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

• JPEGCompressor.h
• JPEGCompressor.cc