DcmCodec Class Reference

abstract base class for a codec object that can be registered in dcmdata and performs transfer syntax transformation (i.e. More...

Inheritance diagram for DcmCodec:

DcmRLECodecDecoder DcmRLECodecEncoder DJCodecDecoder DJCodecEncoder DJLSDecoderBase DJLSEncoderBase DJDecoderBaseline DJDecoderExtended DJDecoderLossless DJDecoderP14SV1 DJDecoderProgressive DJDecoderSpectralSelection DJEncoderBaseline DJEncoderExtended DJEncoderLossless DJEncoderP14SV1 DJEncoderProgressive DJEncoderSpectralSelection DJLSLosslessDecoder DJLSNearLosslessDecoder DJLSLosslessEncoder DJLSNearLosslessEncoder List of all members.

Public Member Functions

 DcmCodec ()
 default constructor
virtual ~DcmCodec ()
 destructor
virtual OFCondition decode (const DcmRepresentationParameter *fromRepParam, DcmPixelSequence *pixSeq, DcmPolymorphOBOW &uncompressedPixelData, const DcmCodecParameter *cp, const DcmStack &objStack) const=0
 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 =0
 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=0
 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=0
 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 =0
 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=0
 determine color model of the decompressed image

Static Public Member Functions

static OFCondition insertStringIfMissing (DcmItem *dataset, const DcmTagKey &tag, const char *val)
 helper function that inserts a string attribute with a given value into a dataset if missing in the dataset.
static OFCondition convertToSecondaryCapture (DcmItem *dataset)
 helper function that converts a dataset containing a DICOM image into a valid (standard extended) Secondary Capture object by inserting all attributes that are type 1/2 in Secondary Capture and missing in the source dataset.
static OFCondition newInstance (DcmItem *dataset, const char *purposeOfReferenceCodingScheme=NULL, const char *purposeOfReferenceCodeValue=NULL, const char *purposeOfReferenceCodeMeaning=NULL)
 create new SOP instance UID and Source Image Sequence referencing the old SOP instance (if present)
static OFCondition updateImageType (DcmItem *dataset)
 set first value of Image Type to DERIVED.
static OFCondition insertCodeSequence (DcmItem *dataset, const DcmTagKey &tagKey, const char *codingSchemeDesignator, const char *codeValue, const char *codeMeaning)
 insert code sequence into the given dataset
static OFCondition determineStartFragment (Uint32 frameNo, Sint32 numberOfFrames, DcmPixelSequence *fromPixSeq, Uint32 &currentItem)
 determine the index number (starting with zero) of the compressed pixel data fragment corresponding to the given frame (also starting with zero)

Detailed Description

abstract base class for a codec object that can be registered in dcmdata and performs transfer syntax transformation (i.e.

compressing, decompressing or transcoding between different compressed transfer syntaxes). When dcmdata is requested to write a transfer syntax that differs from the current one (i.e. the one in which the object was read), dcmdata dynamically searches for a DcmCodec object that is able to create the desired transfer syntax. If no suitable codec is found, the write operation fails.

Definition at line 85 of file dccodec.h.

Member Function Documentation

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

Implemented in DcmRLECodecDecoder, DcmRLECodecEncoder, DJCodecDecoder, DJCodecEncoder, DJLSDecoderBase, and DJLSEncoderBase.

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

Implemented in DcmRLECodecDecoder, DcmRLECodecEncoder, DJCodecDecoder, DJCodecEncoder, DJLSDecoderBase, and DJLSEncoderBase.

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

Implemented in DcmRLECodecDecoder, DcmRLECodecEncoder, DJCodecDecoder, DJCodecEncoder, DJLSDecoderBase, and DJLSEncoderBase.

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

Implemented in DcmRLECodecDecoder, DcmRLECodecEncoder, DJCodecDecoder, DJCodecEncoder, DJLSDecoderBase, and DJLSEncoderBase.

virtual OFBool DcmCodec::canChangeCoding ( const E_TransferSyntax  oldRepType,
const E_TransferSyntax  newRepType 
) const [pure 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.

Implemented in DcmRLECodecDecoder, DcmRLECodecEncoder, DJCodecDecoder, DJCodecEncoder, DJLSDecoderBase, and DJLSEncoderBase.

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

Implemented in DcmRLECodecDecoder, DcmRLECodecEncoder, DJCodecDecoder, DJCodecEncoder, DJLSDecoderBase, and DJLSEncoderBase.

static OFCondition DcmCodec::insertStringIfMissing ( DcmItem *  dataset,
const DcmTagKey &  tag,
const char *  val 
) [static]

helper function that inserts a string attribute with a given value into a dataset if missing in the dataset.

Parameters:
dataset dataset to insert to, must not be NULL.
tag tag key of attribute to check/insert
val string value, may be NULL.
Returns:
EC_Normal if successful, an error code otherwise

static OFCondition DcmCodec::convertToSecondaryCapture ( DcmItem *  dataset  )  [static]

helper function that converts a dataset containing a DICOM image into a valid (standard extended) Secondary Capture object by inserting all attributes that are type 1/2 in Secondary Capture and missing in the source dataset.

Replaces SOP Class UID by Secondary Capture. It does not, however, change an existing SOP Instance UID.

Parameters:
dataset dataset to insert to, must not be NULL.
Returns:
EC_Normal if successful, an error code otherwise

static OFCondition DcmCodec::newInstance ( DcmItem *  dataset,
const char *  purposeOfReferenceCodingScheme = NULL,
const char *  purposeOfReferenceCodeValue = NULL,
const char *  purposeOfReferenceCodeMeaning = NULL 
) [static]

create new SOP instance UID and Source Image Sequence referencing the old SOP instance (if present)

Parameters:
dataset dataset to be modified
purposeOfReferenceCodingScheme coding scheme designator for purpose of reference code sequence
purposeOfReferenceCodeValue code value for purpose of reference code sequence
purposeOfReferenceCodeMeaning code meaning for purpose of reference code sequence
Returns:
EC_Normal if successful, an error code otherwise

static OFCondition DcmCodec::updateImageType ( DcmItem *  dataset  )  [static]

set first value of Image Type to DERIVED.

Parameters:
dataset dataset to be modified
Returns:
EC_Normal if successful, an error code otherwise

static OFCondition DcmCodec::insertCodeSequence ( DcmItem *  dataset,
const DcmTagKey &  tagKey,
const char *  codingSchemeDesignator,
const char *  codeValue,
const char *  codeMeaning 
) [static]

insert code sequence into the given dataset

Parameters:
dataset dataset to insert into
tagKey tag of the code sequence
codingSchemeDesignator coding scheme designator for the sequence item
codeValue code value for the sequence item
codeMeaning code meaning for the sequence item
Returns:
EC_Normal if successul, an error code otherwise

static OFCondition DcmCodec::determineStartFragment ( Uint32  frameNo,
Sint32  numberOfFrames,
DcmPixelSequence *  fromPixSeq,
Uint32 &  currentItem 
) [static]

determine the index number (starting with zero) of the compressed pixel data fragment corresponding to the given frame (also starting with zero)

Parameters:
frameNo frame number
numberOfFrames number of frames of this image
fromPixSeq compressed pixel sequence
currentItem index of compressed pixel data fragment returned in this parameter on success
Returns:
EC_Normal if successful, an error code otherwise

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

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