lti::loadJPEG Class Reference

Functor to read a JPEG file It is NOT thread save, this means, the SAME instance can not be used from different threads or processes at the same time. More...

#include <ltiJPEGFunctor.h>

Inheritance diagram for lti::loadJPEG:

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Collaboration diagram for lti::loadJPEG:

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List of all members.

Public Member Functions
	loadJPEG ()
	~loadJPEG ()
virtual const char *	getTypeName () const
bool	apply (image &theImage)
bool	apply (image &theImage, bool &isGray)
bool	load (const std::string &filename, image &theImage)
bool	load (const std::string &filename, image &theImage, bool &isGray)
bool	load (std::ifstream &file, image &theImage)
bool	checkHeader (const std::string &filename, point &imageSize, std::string &comment, bool &isGray)
virtual functor *	clone () const

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Detailed Description

Functor to read a JPEG file It is NOT thread save, this means, the SAME instance can not be used from different threads or processes at the same time.

If this occurs an unpredictible behaviour must be expected!. If this is required, just use a different instance of the functor for each thread! Example:

 lti::image anImg;                      // an image
 ...
 lti::loadJPEG myImg;                    // the load functor
 lti::loadJPEG::parameters param;        // functor parameters
 param.filename = "~/tmp/theFile.jpeg";  // name of the JPEG file
 myImg.setParameters(param);            // set the functor parameters
 myImg.apply(anImg);                    // load the file

You can also use the more confortable shortcut:

 lti::image anImg;                      // an image
 ...
 lti::loadJPEG loadImg;                  // the load functor
 loadImg.load("~/tmp/theFile.jpeg",img); // load the image.

Exceptions:

BadJpegStream

is thrown when the Stream is corrupted.

See also:

saveJPEG

image

loadJPEG::parameters

For more information on implementation issues see ioJPEG

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Constructor & Destructor Documentation

lti::loadJPEG::loadJPEG

(

)

default constructor

lti::loadJPEG::~loadJPEG

(

)

destructor

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Member Function Documentation

bool lti::loadJPEG::apply	(	image &	theImage,
		bool &	isGray
	)

load JPEG image

Parameters:

	theImage	variable where the image is to be stored
	isGray	returns true when the image is gray scale

bool lti::loadJPEG::apply

(

image &

theImage

)

[virtual]

loads a JPEG image

Parameters:

theImage

variable where the image is to be stored

Reimplemented from lti::ioFunctor.

bool lti::loadJPEG::checkHeader	(	const std::string &	filename,
		point &	imageSize,
		std::string &	comment,
		bool &	isGray
	)

Returns the essential image information.

This function will search the file for all chunks with essential picture information. Scanning stops before the first StartOfScan-Block. That is, all comments that follow the image data are not read!

Parameters:

	filename	name of the file to check
	imageSize	size of the image
	comment	file comments (author, ...)
	isGray	returns true, if grayscale jpeg

Returns:

true if file is ok

virtual functor* lti::loadJPEG::clone

(

)

const [virtual]

returns a pointer to a clone of the functor.

Implements lti::functor.

virtual const char* lti::loadJPEG::getTypeName

(

)

const [virtual]

returns the name of this type

Reimplemented from lti::ioJPEG.

bool lti::loadJPEG::load	(	std::ifstream &	file,
		image &	theImage
	)

method for loading a JPEG image from an already opened stream.

bool lti::loadJPEG::load	(	const std::string &	filename,
		image &	theImage,
		bool &	isGray
	)

shortcut for loading a JPEG

Parameters:

	filename	name of the file to read
	theImage	variable where the image is stored
	isGray	will be set with true if the image contains only gray values.

bool lti::loadJPEG::load	(	const std::string &	filename,
		image &	theImage
	)			[virtual]

shortcut for loading a JPEG

Parameters:

	filename	name of the file to read
	theImage	variable where the image is stored

Reimplemented from lti::ioFunctor.

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

• ltiJPEGFunctor.h