Reads / writes Joint Photographic Experts Group (JPEG) files. More...

#include <iJPEG.h>

Inheritance diagram for imagen::iJPEG:

Public Types
enum	JpegDCTMethod { DCTInteger, DCTFastInteger, DCTFloat }
	JPEG DCT Method. More...
enum	JpegSubsampling { SubSample444, SubSample422, SubSample411 }
	JPEG Subsampling. More...
Public Member Functions
	iJPEG ()
	Constructs a null image.
	iJPEG (const iJPEG &img)
	Copy constructor.
	iJPEG (const iAbstractImage &img)
	iAbstractImage copy constructor.
	iJPEG (int w, int h, iImageFormat f)
	Constructs an image with the given size and format.
	iJPEG (Iubyte *d, int w, int h, iImageFormat f, int b)
	Constructs an image using an existing memory buffer.
	iJPEG (const char *filename)
	Loads a JPEG image file from disk.
	iJPEG (Iubyte *buf, int len)
	Loads a JPEG image from an existing memory buffer.
	iJPEG (iDataStream *s)
	Loads a JPEG image using an existing data stream.
	~iJPEG ()
	Destructor.
void	clear ()
	Detaches this image from the image data and resets all data members to their initial values.
bool	isFormatSupported (iImageFormat fmt) const
	Checks whether or not a given image color format is supported by this image type.
void	setQuality (int q)
	Sets the quality to use when writing JPEG images.
int	getQuality () const
	Gets the quality used when writing JPEG images.
void	setSmoothing (int sm)
	Sets the amount of smoothing to use when writing JPEG images.
int	getSmoothing () const
	Gets the amount of smoothing used when writing JPEG images.
void	setDCTMethod (JpegDCTMethod dct)
	Sets the algorithm to use for the DCT step when writing JPEG images.
JpegDCTMethod	getDCTMethod () const
	Gets the algorithm used for the DCT step when writing JPEG images.
void	setSubsampling (JpegSubsampling ss)
	Sets the subsampling to use when writing JPEG images.
JpegSubsampling	getSubsampling () const
	Gets the subsampling used when writing JPEG images.
void	enableProgression (bool bprg)
	Enables progression when writing a JPEG image.
void	enableOptimization (bool bopt)
	Enables optimization when writing a JPEG image.
void	enableChromaDownsampling (bool bdown)
	Enables chroma downsampling when writing a JPEG image.
void	saveExif (bool bexif)
	Saves Exif metadata when writing a JPEG image.
void	saveThumbnail (bool bthumb)
	Saves an embedded thumbnail image when writing a JPEG image.
iJPEG &	operator= (const iJPEG &img)
iJPEG &	operator= (const iAbstractImage &img)
Static Public Member Functions
static bool	isValid (iDataStream *s)
Protected Member Functions
void	init ()
bool	loadImage ()
bool	saveImage ()

Detailed Description

Reads / writes Joint Photographic Experts Group (JPEG) files.

Extensions:
jpg, jpeg, jpe, jif, jfif, and jfi

Image types:
Grayscale and truecolor

Pixel Depths:
8-bit and 24-bit

TODO:
Exif metadata
Thumbnail
Comments
Restart markers

Member Enumeration Documentation

enum imagen::iJPEG::JpegDCTMethod

JPEG DCT Method.

Enumerator:

DCTInteger
DCTFastInteger
DCTFloat

enum imagen::iJPEG::JpegSubsampling

JPEG Subsampling.

Enumerator:

SubSample444	Best quality.
SubSample422	Intermediate.
SubSample411	Smallest size.

Constructor & Destructor Documentation

imagen::iJPEG::iJPEG ( )

Constructs a null image.

imagen::iJPEG::iJPEG ( const iJPEG & img )

Copy constructor.

This copies all image attributes, and attaches itself to img's shared data.

imagen::iJPEG::iJPEG ( const iAbstractImage & img )

iAbstractImage copy constructor.

imagen::iJPEG::iJPEG	(	int	w,
		int	h,
		iImageFormat	f
	)

Constructs an image with the given size and format.

The image data will be allocated, but not initialized.

Parameters:

w	: Image width.
h	: Image height.
f	: Image format.

imagen::iJPEG::iJPEG	(	Iubyte *	d,
		int	w,
		int	h,
		iImageFormat	f,
		int	b
	)

Constructs an image using an existing memory buffer.

The memory buffer will not be deleted at destruction.

See also:: loadData()

imagen::iJPEG::iJPEG ( const char * filename )

Loads a JPEG image file from disk.

See also:: load( const char *filename )

imagen::iJPEG::iJPEG	(	Iubyte *	buf,
		int	len
	)

Loads a JPEG image from an existing memory buffer.

See also:: load( Iubyte *buf, int len )

imagen::iJPEG::iJPEG ( iDataStream * s )

Loads a JPEG image using an existing data stream.

See also:: load( iDataStream *s )

imagen::iJPEG::~iJPEG ( )

Destructor.

Member Function Documentation

void imagen::iJPEG::clear ( ) [virtual]

Detaches this image from the image data and resets all data members to their initial values.

Reimplemented from imagen::iAbstractImage.

bool imagen::iJPEG::isFormatSupported ( iImageFormat fmt ) const [virtual]

Checks whether or not a given image color format is supported by this image type.

Returns:: True if the format is supported, else false.

Implements imagen::iAbstractImage.

static bool imagen::iJPEG::isValid ( iDataStream * s ) [static]

void imagen::iJPEG::setQuality ( int q )

Sets the quality to use when writing JPEG images.

Must be in the range of 0 to 100.
It is set to a reasonable default: 85.

int imagen::iJPEG::getQuality ( ) const [inline]

Gets the quality used when writing JPEG images.

void imagen::iJPEG::setSmoothing ( int sm )

Sets the amount of smoothing to use when writing JPEG images.

Must be in the range of 0 to 100.
It is set to 0 (no smoothing) by default.

int imagen::iJPEG::getSmoothing ( ) const [inline]

Gets the amount of smoothing used when writing JPEG images.

void imagen::iJPEG::setDCTMethod ( JpegDCTMethod dct ) [inline]

Sets the algorithm to use for the DCT step when writing JPEG images.

It is set to iJPEG::DCTInteger by default.

JpegDCTMethod imagen::iJPEG::getDCTMethod ( ) const [inline]

Gets the algorithm used for the DCT step when writing JPEG images.

void imagen::iJPEG::setSubsampling ( JpegSubsampling ss ) [inline]

Sets the subsampling to use when writing JPEG images.

It is set to iJPEG::SubSample411 by default.

JpegSubsampling imagen::iJPEG::getSubsampling ( ) const [inline]

Gets the subsampling used when writing JPEG images.

void imagen::iJPEG::enableProgression ( bool bprg ) [inline]

Enables progression when writing a JPEG image.

Progression is disabled by default.

void imagen::iJPEG::enableOptimization ( bool bopt ) [inline]

Enables optimization when writing a JPEG image.

Optimization uses more time and memory, but yields slightly smaller image sizes.
Optimization is enabled by default.

void imagen::iJPEG::enableChromaDownsampling ( bool bdown ) [inline]

Enables chroma downsampling when writing a JPEG image.

Disabling chroma downsampling can slightly improve image quality, but enlarge the image size.
Chroma downsampling is enabled by default.

void imagen::iJPEG::saveExif ( bool bexif ) [inline]

Saves Exif metadata when writing a JPEG image.

void imagen::iJPEG::saveThumbnail ( bool bthumb ) [inline]

Saves an embedded thumbnail image when writing a JPEG image.

iJPEG& imagen::iJPEG::operator= ( const iJPEG & img )

iJPEG& imagen::iJPEG::operator= ( const iAbstractImage & img )

Reimplemented from imagen::iAbstractImage.

void imagen::iJPEG::init ( ) [protected]

Reimplemented from imagen::iAbstractImage.

bool imagen::iJPEG::loadImage ( ) [protected, virtual]

Implements imagen::iAbstractImage.

bool imagen::iJPEG::saveImage ( ) [protected, virtual]

Implements imagen::iAbstractImage.

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

iJPEG.h

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation