DJCodecEncoder Class Reference

abstract codec class for JPEG encoders. More...

Inheritance diagram for DJCodecEncoder:

List of all members.

Public Member Functions
	DJCodecEncoder ()
	default constructor
virtual	~DJCodecEncoder ()
	destructor
virtual OFCondition	decode (const DcmRepresentationParameter *fromRepParam, DcmPixelSequence *pixSeq, DcmPolymorphOBOW &uncompressedPixelData, const DcmCodecParameter *cp, const DcmStack &objStack) const
	decompresses the given pixel sequence and stores the result in the given uncompressedPixelData element.
virtual OFCondition	decodeFrame (const DcmRepresentationParameter *fromParam, DcmPixelSequence *fromPixSeq, const DcmCodecParameter *cp, DcmItem *dataset, Uint32 frameNo, Uint32 &startFragment, void *buffer, Uint32 bufSize, OFString &decompressedColorModel) const
	decompresses a single frame from the given pixel sequence and stores the result in the given buffer.
virtual OFCondition	encode (const Uint16 *pixelData, const Uint32 length, const DcmRepresentationParameter *toRepParam, DcmPixelSequence *&pixSeq, const DcmCodecParameter *cp, DcmStack &objStack) const
	compresses the given uncompressed DICOM image and stores the result in the given pixSeq element.
virtual OFCondition	encode (const E_TransferSyntax fromRepType, const DcmRepresentationParameter *fromRepParam, DcmPixelSequence *fromPixSeq, const DcmRepresentationParameter *toRepParam, DcmPixelSequence *&toPixSeq, const DcmCodecParameter *cp, DcmStack &objStack) const
	transcodes (re-compresses) the given compressed DICOM image and stores the result in the given toPixSeq element.
virtual OFBool	canChangeCoding (const E_TransferSyntax oldRepType, const E_TransferSyntax newRepType) const
	checks if this codec is able to convert from the given current transfer syntax to the given new transfer syntax
virtual OFCondition	determineDecompressedColorModel (const DcmRepresentationParameter *fromParam, DcmPixelSequence *fromPixSeq, const DcmCodecParameter *cp, DcmItem *dataset, OFString &decompressedColorModel) const
	determine color model of the decompressed image
virtual E_TransferSyntax	supportedTransferSyntax () const =0
	returns the transfer syntax that this particular codec is able to encode and decode.
Static Protected Member Functions
static void	appendCompressionRatio (OFString &arg, double ratio)
	format compression ratio as string and append to given string object.
static OFCondition	togglePlanarConfiguration8 (Uint8 *pixelData, const unsigned long numValues, const Uint16 samplesPerPixel, const Uint16 oldPlanarConfig)
	toggles Planar Configuration of 8-bit pixel data from "by pixel" to "by plane" and vice versa.
static OFCondition	togglePlanarConfiguration16 (Uint16 *pixelData, const unsigned long numValues, const Uint16 samplesPerPixel, const Uint16 oldPlanarConfig)
	toggles Planar Configuration of 16-bit pixel data from "by pixel" to "by plane" and vice versa.
Private Member Functions
virtual OFCondition	encodeColorImage (OFBool YBRmode, DcmItem *dataset, const DcmRepresentationParameter *toRepParam, DcmPixelSequence *&pixSeq, const DJCodecParameter *cp, double &compressionRatio) const
	compresses the given uncompressed DICOM color image and stores the result in the given pixSeq element.
virtual OFCondition	encodeMonochromeImage (DcmItem *dataset, const DcmRepresentationParameter *toRepParam, DcmPixelSequence *&pixSeq, const DJCodecParameter *cp, double &compressionRatio) const
	compresses the given uncompressed monochrome DICOM image and stores the result in the given pixSeq element.
virtual OFCondition	encodeTrueLossless (const DcmRepresentationParameter *toRepParam, DcmPixelSequence *&pixSeq, const DcmCodecParameter *cp, DcmStack &objStack) const
	compresses the given uncompressed DICOM image and stores the result in the given pixSeq element.
virtual OFCondition	updateLossyCompressionRatio (DcmItem *dataset, double ratio) const
	create Lossy Image Compression and Lossy Image Compression Ratio.
virtual OFCondition	updateDerivationDescription (DcmItem *dataset, const DcmRepresentationParameter *toRepParam, const DJCodecParameter *cp, Uint8 bitsPerSample, double ratio) const
	create Derivation Description.
virtual OFCondition	adjustOverlays (DcmItem *dataset, DicomImage &image) const
	for all overlay groups create (60xx,3000) Overlay Data.
virtual OFBool	isLosslessProcess () const =0
	returns true if the transfer syntax supported by this codec is lossless.
virtual void	createDerivationDescription (const DcmRepresentationParameter *toRepParam, const DJCodecParameter *cp, Uint8 bitsPerSample, double ratio, OFString &derivationDescription) const =0
	creates 'derivation description' string after encoding.
virtual DJEncoder *	createEncoderInstance (const DcmRepresentationParameter *toRepParam, const DJCodecParameter *cp, Uint8 bitsPerSample) const =0
	creates an instance of the compression library to be used for encoding/decoding.
OFCondition	updatePlanarConfiguration (DcmItem *item, const Uint16 newPlanConf) const
Static Private Member Functions
static OFCondition	correctVOIWindows (DcmItem *dataset, double voiOffset, double voiFactor)
	modifies all VOI window center/width settings in the image.

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Detailed Description

abstract codec class for JPEG encoders.

This abstract class contains most of the application logic needed for a dcmdata codec object that implements a JPEG encoder using the DJEncoder interface to the underlying JPEG implementation. This class only supports compression, it neither implements decoding nor transcoding.

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Member Function Documentation

virtual OFCondition DJCodecEncoder::adjustOverlays	(	DcmItem *	dataset,
		DicomImage &	image
	)		const [private, virtual]

for all overlay groups create (60xx,3000) Overlay Data.

Parameters:

dataset	dataset to be modified
image	DicomImage object for this dataset

Returns:

EC_Normal if successful, an error code otherwise

static void DJCodecEncoder::appendCompressionRatio	(	OFString &	arg,
		double	ratio
	)		[static, protected]

format compression ratio as string and append to given string object.

Parameters:

arg	string to append to
ratio	compression ratio

virtual OFBool DJCodecEncoder::canChangeCoding	(	const E_TransferSyntax	oldRepType,
		const E_TransferSyntax	newRepType
	)		const [virtual]

checks if this codec is able to convert from the given current transfer syntax to the given new transfer syntax

Parameters:

oldRepType	current transfer syntax
newRepType	desired new transfer syntax

Returns:

true if transformation is supported by this codec, false otherwise.

Implements DcmCodec.

static OFCondition DJCodecEncoder::correctVOIWindows	(	DcmItem *	dataset,
		double	voiOffset,
		double	voiFactor
	)		[static, private]

modifies all VOI window center/width settings in the image.

Modifications are based on the pixel value mapping f(x) = (x+voiOffset)*voiFactor

Parameters:

dataset	dataset to be updated
voiOffset	offset to be added to each pixel
voiFactor	factor to be multiplied

Returns:

EC_Normal if successful, an error code otherwise

virtual void DJCodecEncoder::createDerivationDescription	(	const DcmRepresentationParameter *	toRepParam,
		const DJCodecParameter *	cp,
		Uint8	bitsPerSample,
		double	ratio,
		OFString &	derivationDescription
	)		const [private, pure virtual]

creates 'derivation description' string after encoding.

Parameters:

toRepParam	representation parameter passed to encode()
cp	codec parameter passed to encode()
bitsPerSample	bits per sample of the original image data prior to compression
ratio	image compression ratio. This is not the "quality factor" but the real effective ratio between compressed and uncompressed image, i. e. 30 means a 30:1 lossy compression.
derivation	description returned in this parameter which is initially empty

Implemented in DJEncoderBaseline, DJEncoderExtended, DJEncoderLossless, DJEncoderProgressive, DJEncoderSpectralSelection, and DJEncoderP14SV1.

virtual DJEncoder* DJCodecEncoder::createEncoderInstance	(	const DcmRepresentationParameter *	toRepParam,
		const DJCodecParameter *	cp,
		Uint8	bitsPerSample
	)		const [private, pure virtual]

creates an instance of the compression library to be used for encoding/decoding.

Parameters:

toRepParam	representation parameter passed to encode()
cp	codec parameter passed to encode()
bitsPerSample	bits per sample for the image data

Returns:

pointer to newly allocated codec object

Implemented in DJEncoderBaseline, DJEncoderExtended, DJEncoderLossless, DJEncoderProgressive, DJEncoderSpectralSelection, and DJEncoderP14SV1.

virtual OFCondition DJCodecEncoder::decode	(	const DcmRepresentationParameter *	fromRepParam,
		DcmPixelSequence *	pixSeq,
		DcmPolymorphOBOW &	uncompressedPixelData,
		const DcmCodecParameter *	cp,
		const DcmStack &	objStack
	)		const [virtual]

decompresses the given pixel sequence and stores the result in the given uncompressedPixelData element.

Parameters:

fromRepParam	current representation parameter of compressed data, may be NULL
pixSeq	compressed pixel sequence
uncompressedPixelData	uncompressed pixel data stored in this element
cp	codec parameters for this codec
objStack	stack pointing to the location of the pixel data element in the current dataset.

Returns:

EC_Normal if successful, an error code otherwise.

Implements DcmCodec.

virtual OFCondition DJCodecEncoder::decodeFrame	(	const DcmRepresentationParameter *	fromParam,
		DcmPixelSequence *	fromPixSeq,
		const DcmCodecParameter *	cp,
		DcmItem *	dataset,
		Uint32	frameNo,
		Uint32 &	startFragment,
		void *	buffer,
		Uint32	bufSize,
		OFString &	decompressedColorModel
	)		const [virtual]

decompresses a single frame from the given pixel sequence and stores the result in the given buffer.

Parameters:

fromParam	representation parameter of current compressed representation, may be NULL.
fromPixSeq	compressed pixel sequence
cp	codec parameters for this codec
dataset	pointer to dataset in which pixel data element is contained
frameNo	number of frame, starting with 0 for the first frame
startFragment	index of the compressed fragment that contains all or the first part of the compressed bitstream for the given frameNo. Upon successful return this parameter is updated to contain the index of the first compressed fragment of the next frame. When unknown, zero should be passed. In this case the decompression algorithm will try to determine the index by itself, which will always work if frames are decompressed in increasing order from first to last, but may fail if frames are decompressed in random order, multiple fragments per frame and multiple frames are present in the dataset, and the offset table is empty.
buffer	pointer to buffer where frame is to be stored
bufSize	size of buffer in bytes
decompressedColorModel	upon successful return, the color model of the decompressed image (which may be different from the one used in the compressed images) is returned in this parameter.

Returns:

EC_Normal if successful, an error code otherwise.

Implements DcmCodec.

virtual OFCondition DJCodecEncoder::determineDecompressedColorModel	(	const DcmRepresentationParameter *	fromParam,
		DcmPixelSequence *	fromPixSeq,
		const DcmCodecParameter *	cp,
		DcmItem *	dataset,
		OFString &	decompressedColorModel
	)		const [virtual]

determine color model of the decompressed image

Parameters:

fromParam	representation parameter of current compressed representation, may be NULL
fromPixSeq	compressed pixel sequence
cp	codec parameters for this codec
dataset	pointer to dataset in which pixel data element is contained
dataset	pointer to DICOM dataset in which this pixel data object is located. Used to access photometric interpretation.
decompressedColorModel	upon successful return, the color model of the decompressed image (which may be different from the one used in the compressed images) is returned in this parameter

Returns:

EC_Normal if successful, an error code otherwise

Implements DcmCodec.

virtual OFCondition DJCodecEncoder::encode	(	const Uint16 *	pixelData,
		const Uint32	length,
		const DcmRepresentationParameter *	toRepParam,
		DcmPixelSequence *&	pixSeq,
		const DcmCodecParameter *	cp,
		DcmStack &	objStack
	)		const [virtual]

compresses the given uncompressed DICOM image and stores the result in the given pixSeq element.

Parameters:

pixelData	pointer to the uncompressed image data in OW format and local byte order
length	of the pixel data field in bytes
toRepParam	representation parameter describing the desired compressed representation (e.g. JPEG quality)
pixSeq	compressed pixel sequence (pointer to new DcmPixelSequence object allocated on heap) returned in this parameter upon success.
cp	codec parameters for this codec
objStack	stack pointing to the location of the pixel data element in the current dataset.

Returns:

EC_Normal if successful, an error code otherwise.

Implements DcmCodec.

virtual OFCondition DJCodecEncoder::encode	(	const E_TransferSyntax	fromRepType,
		const DcmRepresentationParameter *	fromRepParam,
		DcmPixelSequence *	fromPixSeq,
		const DcmRepresentationParameter *	toRepParam,
		DcmPixelSequence *&	toPixSeq,
		const DcmCodecParameter *	cp,
		DcmStack &	objStack
	)		const [virtual]

transcodes (re-compresses) the given compressed DICOM image and stores the result in the given toPixSeq element.

Parameters:

fromRepType	current transfer syntax of the compressed image
fromRepParam	current representation parameter of compressed data, may be NULL
fromPixSeq	compressed pixel sequence
toRepParam	representation parameter describing the desired new compressed representation (e.g. JPEG quality)
toPixSeq	compressed pixel sequence (pointer to new DcmPixelSequence object allocated on heap) returned in this parameter upon success.
cp	codec parameters for this codec
objStack	stack pointing to the location of the pixel data element in the current dataset.

Returns:

EC_Normal if successful, an error code otherwise.

Implements DcmCodec.

virtual OFCondition DJCodecEncoder::encodeColorImage	(	OFBool	YBRmode,
		DcmItem *	dataset,
		const DcmRepresentationParameter *	toRepParam,
		DcmPixelSequence *&	pixSeq,
		const DJCodecParameter *	cp,
		double &	compressionRatio
	)		const [private, virtual]

compresses the given uncompressed DICOM color image and stores the result in the given pixSeq element.

Parameters:

YBRmode	true if the source image has YBR_FULL or YBR_FULL_422 photometric interpretation and can thus be compressed without color space conversion.
dataset	DICOM dataset containing the pixel data as well as descriptive attributes
toRepParam	representation parameter describing the desired compressed representation (e.g. JPEG quality)
pixSeq	compressed pixel sequence (pointer to new DcmPixelSequence object allocated on heap) returned in this parameter upon success.
cp	codec parameters for this codec
compressionRatio	compression ratio returned in this parameter if successful.

Returns:

EC_Normal if successful, an error code otherwise.

virtual OFCondition DJCodecEncoder::encodeMonochromeImage	(	DcmItem *	dataset,
		const DcmRepresentationParameter *	toRepParam,
		DcmPixelSequence *&	pixSeq,
		const DJCodecParameter *	cp,
		double &	compressionRatio
	)		const [private, virtual]

compresses the given uncompressed monochrome DICOM image and stores the result in the given pixSeq element.

Parameters:

dataset	DICOM dataset containing the pixel data as well as descriptive attributes
toRepParam	representation parameter describing the desired compressed representation (e.g. JPEG quality)
pixSeq	compressed pixel sequence (pointer to new DcmPixelSequence object allocated on heap) returned in this parameter upon success.
cp	codec parameters for this codec
compressionRatio	compression ratio returned in this parameter if successful.

Returns:

EC_Normal if successful, an error code otherwise.

virtual OFCondition DJCodecEncoder::encodeTrueLossless	(	const DcmRepresentationParameter *	toRepParam,
		DcmPixelSequence *&	pixSeq,
		const DcmCodecParameter *	cp,
		DcmStack &	objStack
	)		const [private, virtual]

compresses the given uncompressed DICOM image and stores the result in the given pixSeq element.

No colorspace conversions, modality or windowing transformations are applied to guarantee, that the quality of the source image is fully preserved.

Parameters:

toRepParam	- [in] representation parameter describing the desired
pixSeq	- [out] compressed pixel sequence (pointer to new DcmPixelSequence object allocated on heap) returned in this parameter upon success
cp	- [in] codec parameters for this codec
objStack	- [in/out] stack pointing to the location of the pixel data element in the current dataset.

Returns:

EC_Normal if successful, an error code otherwise.

virtual OFBool DJCodecEncoder::isLosslessProcess

(

)

const [private, pure virtual]

returns true if the transfer syntax supported by this codec is lossless.

Returns:

lossless flag

Implemented in DJEncoderBaseline, DJEncoderExtended, DJEncoderLossless, DJEncoderProgressive, DJEncoderSpectralSelection, and DJEncoderP14SV1.

virtual E_TransferSyntax DJCodecEncoder::supportedTransferSyntax

(

)

const [pure virtual]

returns the transfer syntax that this particular codec is able to encode and decode.

Returns:

supported transfer syntax

Implemented in DJEncoderBaseline, DJEncoderExtended, DJEncoderLossless, DJEncoderProgressive, DJEncoderSpectralSelection, and DJEncoderP14SV1.

static OFCondition DJCodecEncoder::togglePlanarConfiguration16	(	Uint16 *	pixelData,
		const unsigned long	numValues,
		const Uint16	samplesPerPixel,
		const Uint16	oldPlanarConfig
	)		[static, protected]

toggles Planar Configuration of 16-bit pixel data from "by pixel" to "by plane" and vice versa.

Parameters:

pixelData	- [in/out] Original pixel data (input), contains pixel data with toggled Planar configuration after returning (output).
numValues	- [in] The number of 16 bit values in pixelData
samplesPerPixel	- [in] Number of components for one pixel
oldPlanarConfig	- [in] The old Planar Configuration, that should be toggled. 0 means "by pixel", 1 "by color"

Returns:

EC_Normal, if conversion was successful; error else

static OFCondition DJCodecEncoder::togglePlanarConfiguration8	(	Uint8 *	pixelData,
		const unsigned long	numValues,
		const Uint16	samplesPerPixel,
		const Uint16	oldPlanarConfig
	)		[static, protected]

toggles Planar Configuration of 8-bit pixel data from "by pixel" to "by plane" and vice versa.

Parameters:

pixelData	- [in/out] Original pixel data (input), contains pixel data with toggled Planar configuration after returning (output).
numValues	- [in] The number of 8 bit values in pixelData
samplesPerPixel	- [in] Number of components for one pixel
oldPlanarConfig	- [in] The old Planar Configuration, that should be toggled. 0 means "by pixel", 1 "by color"

Returns:

EC_Normal, if conversion was successful; error else

virtual OFCondition DJCodecEncoder::updateDerivationDescription	(	DcmItem *	dataset,
		const DcmRepresentationParameter *	toRepParam,
		const DJCodecParameter *	cp,
		Uint8	bitsPerSample,
		double	ratio
	)		const [private, virtual]

create Derivation Description.

Parameters:

dataset	dataset to be modified
toRepParam	representation parameter passed to encode()
cp	codec parameter passed to encode()
bitsPerSample	bits per sample of the original image data prior to compression
ratio	image compression ratio. This is not the "quality factor" but the real effective ratio between compressed and uncompressed image, i. e. 30 means a 30:1 lossy compression.

Returns:

EC_Normal if successful, an error code otherwise

virtual OFCondition DJCodecEncoder::updateLossyCompressionRatio	(	DcmItem *	dataset,
		double	ratio
	)		const [private, virtual]

create Lossy Image Compression and Lossy Image Compression Ratio.

Parameters:

dataset	dataset to be modified
ratio	image compression ratio > 1. This is not the "quality factor" but the real effective ratio between compressed and uncompressed image, i. e. 30 means a 30:1 lossy compression.

Returns:

EC_Normal if successful, an error code otherwise

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

• dcmjpeg/include/dcmtk/dcmjpeg/djcodece.h