DcmVR Class Reference

a class representing a DICOM Value Representation More...

Public Member Functions
	DcmVR ()
	default constructor
	DcmVR (DcmEVR evr)
	constructor More...
	DcmVR (const char *vrName)
	constructor. More...
	DcmVR (const DcmVR &avr)
	copy constructor More...
void	setVR (DcmEVR evr)
	assign new VR value More...
void	setVR (const char *vrName)
	assign new VR value by name. More...
void	setVR (const DcmVR &avr)
	assign new VR value More...
DcmVR &	operator= (const DcmVR &arg)
	copy assignment operator More...
DcmEVR	getEVR () const
	get enumerated VR managed by this object More...
DcmEVR	getValidEVR () const
	get enumerated standard VR managed by this object. More...
const char *	getVRName () const
	get symbolic VR name for this object More...
const char *	getValidVRName () const
	get symbolic standard VR name for this object. More...
size_t	getValueWidth () const
	compute the size for non-empty values of this VR. More...
OFBool	isInvalid () const
	returns true if VR is invalid, i.e. EVR_invalid More...
OFBool	isUnknown () const
	returns true if VR is unknown, i.e. EVR_UNKNOWN or EVR_UNKNOWN2B More...
OFBool	isStandard () const
	returns true if VR is a standard DICOM VR More...
OFBool	isForInternalUseOnly () const
	returns true if VR is for internal use only More...
OFBool	isaString () const
	returns true if VR represents a string. More...
OFBool	isaNumber () const
	returns true if VR represents a number (either encoded as a string or in binary format). More...
OFBool	isInteger () const
	returns true if VR represents an integer number (either encoded as a string or in binary format). More...
OFBool	isUnsigned () const
	returns true if VR represents an unsigned number (either encoded as a string or in binary format). More...
OFBool	usesExtendedLengthEncoding () const
	returns true if VR uses an extended length encoding for explicit transfer syntaxes More...
OFBool	supportsUndefinedLength () const
	returns true if VR supports undefined length for the value length field and a sequence delimitation item marks the end of the value field More...
OFBool	isEquivalent (const DcmVR &avr) const
	check if VRs are equivalent. More...
Uint32	getMinValueLength () const
	return minimum length of a single value with this VR. More...
Uint32	getMaxValueLength () const
	return maximum length of a single value with this VR. More...
OFBool	isAffectedBySpecificCharacterSet () const
	return whether elements of this VR are affected by SpecificCharacterSet More...
const OFString &	getDelimiterChars () const
	retrieve delimiter characters to be used for character set conversion (to switch back to the default character set in case code extension techniques like ISO 2022 are used). More...
OFBool	isLengthInChar () const
	check whether the maximum or minimum length of a value with this VR is in bytes or characters. More...

Private Attributes
DcmEVR	vr
	the enumerated VR value

Detailed Description

a class representing a DICOM Value Representation

Constructor & Destructor Documentation

DcmVR() [1/3]

DcmVR::DcmVR ( DcmEVR  evr )

inline

constructor

Parameters

evr	enumerated VR value

DcmVR() [2/3]

DcmVR::DcmVR ( const char *  vrName )

inline

constructor.

Please note that only the first two characters of the passed string are actually checked. Value Representations that are labeled for internal use only are mapped to an unknown VR. See setVR() for more details.

Parameters

vrName

symbolic name of value representation

DcmVR() [3/3]

DcmVR::DcmVR ( const DcmVR &  avr )

inline

copy constructor

Parameters

avr

VR value

Member Function Documentation

getDelimiterChars()

const OFString& DcmVR::getDelimiterChars

(

)

const

retrieve delimiter characters to be used for character set conversion (to switch back to the default character set in case code extension techniques like ISO 2022 are used).

Returns

a reference to an OFString containing the delimiter characters for this VR or a reference to an empty OFString.

getEVR()

DcmEVR DcmVR::getEVR ( ) const

inline

get enumerated VR managed by this object

Returns

enumerated VR

getMaxValueLength()

Uint32 DcmVR::getMaxValueLength

(

)

const

return maximum length of a single value with this VR.

Whether the returned length is in bytes or characters can be determined by isLengthInChar().

Returns

maximum length of a value

getMinValueLength()

Uint32 DcmVR::getMinValueLength

(

)

const

return minimum length of a single value with this VR.

Whether the returned length is in bytes or characters can be determined by isLengthInChar().

Returns

minimum length of a value

getValidEVR()

DcmEVR DcmVR::getValidEVR

(

)

const

get enumerated standard VR managed by this object.

If this object manages a non-standard, internal VR such as EVR_ox, this method returns the enumerated VR to which the internal VR will be mapped when writing the DICOM object.

Please note that some VR, e.g. EVR_pixelItem, won't be written as EVR_UNKNOWN, although this method will return that value for them. This means that e.g. usesExtendedLengthEncoding() for the returned VR might not be correct.

Also note that DcmItem::checkAndUpdateVR() will in some cases influence the VR that is written out.

Returns

enumerated VR

getValidVRName()

const char* DcmVR::getValidVRName

(

)

const

get symbolic standard VR name for this object.

If this object manages a non-standard, internal VR such as EVR_ox, this method returns the name of the VR to which the internal VR will be mapped when writing the DICOM object.

Returns

VR name string, never NULL

getValueWidth()

size_t DcmVR::getValueWidth

(

)

const

compute the size for non-empty values of this VR.

For fixed size VRs such as OW, US, SL, the method returns the size of each value, in bytes. For variable length VRs (strings), it returns 1. For internal VRs it returns 0.

Returns

size of values of this VR

getVRName()

const char* DcmVR::getVRName

(

)

const

get symbolic VR name for this object

Returns

VR name string, never NULL

isAffectedBySpecificCharacterSet()

OFBool DcmVR::isAffectedBySpecificCharacterSet

(

)

const

return whether elements of this VR are affected by SpecificCharacterSet

Returns

true for the following VRs: PN, LO, LT, SH, ST, UC and UT, false for all others.

isaNumber()

OFBool DcmVR::isaNumber

(

)

const

returns true if VR represents a number (either encoded as a string or in binary format).

Note

This method is only applicable to standard DICOM VRs.

Returns

true if VR represents a number, false otherwise

isaString()

OFBool DcmVR::isaString

(

)

const

returns true if VR represents a string.

Note

This method is only applicable to standard DICOM VRs.

Returns

true if VR represents a string, false otherwise

isEquivalent()

OFBool DcmVR::isEquivalent

(

const DcmVR &

avr

)

const

check if VRs are equivalent.

VRs are considered equivalent if equal or if one of them is an internal VR and the other one is a possible standard VR to which the internal one maps.

Parameters

avr	VR to compare with

Returns

true if VRs are equivalent, false otherwise

isForInternalUseOnly()

OFBool DcmVR::isForInternalUseOnly

(

)

const

returns true if VR is for internal use only

Returns

true if VR is for internal use only, false otherwise

isInteger()

OFBool DcmVR::isInteger

(

)

const

returns true if VR represents an integer number (either encoded as a string or in binary format).

Note

This method is only applicable to standard DICOM VRs.

Returns

true if VR represents an integer number, false otherwise

isInvalid()

OFBool DcmVR::isInvalid

(

)

const

returns true if VR is invalid, i.e. EVR_invalid

Returns

true if VR is invalid, false otherwise

isLengthInChar()

OFBool DcmVR::isLengthInChar

(

)

const

check whether the maximum or minimum length of a value with this VR is in bytes or characters.

See getMinValueLength() and getMaxValueLength().

Returns

true if length is stated in characters, false if in bytes

isStandard()

OFBool DcmVR::isStandard

(

)

const

returns true if VR is a standard DICOM VR

Returns

true if VR is a standard DICOM VR, false otherwise

isUnknown()

OFBool DcmVR::isUnknown

(

)

const

returns true if VR is unknown, i.e. EVR_UNKNOWN or EVR_UNKNOWN2B

Returns

true if VR is unknown, false otherwise

isUnsigned()

OFBool DcmVR::isUnsigned

(

)

const

returns true if VR represents an unsigned number (either encoded as a string or in binary format).

Note

This method is only applicable to standard DICOM VRs.

Returns

true if VR represents an unsigned number, false otherwise

operator=()

DcmVR& DcmVR::operator= ( const DcmVR &  arg )

inline

copy assignment operator

Parameters

arg	vr to assign from

Returns

reference to this object

References vr.

setVR() [1/3]

void DcmVR::setVR

(

const char *

vrName

)

assign new VR value by name.

Please note that only the first two characters of the passed string are actually checked. Value Representations that are labeled for internal use only are ignored, so they are mapped to an unknown VR. For unknown VRs consisting of two uppercase letters, extended length (4 bytes) is assumed, since it could be a new DICOM VR that is not yet supported. For other unknown VRs consisting of characters in the range of 32 to 127, a 2-byte length field is assumed. This also applies to a VR string of "??", which has been observed in the wild not to use extended length. All other VR strings are considered invalid.

Parameters

vrName

symbolic name of value representation

setVR() [2/3]

void DcmVR::setVR ( const DcmVR &  avr )

inline

assign new VR value

Parameters

avr

VR value

References vr.

setVR() [3/3]

void DcmVR::setVR

(

DcmEVR

evr

)

assign new VR value

Parameters

evr	enumerated VR value

supportsUndefinedLength()

OFBool DcmVR::supportsUndefinedLength

(

)

const

returns true if VR supports undefined length for the value length field and a sequence delimitation item marks the end of the value field

Returns

true if VR supports undefined length, false otherwise

usesExtendedLengthEncoding()

OFBool DcmVR::usesExtendedLengthEncoding

(

)

const

returns true if VR uses an extended length encoding for explicit transfer syntaxes

Returns

true if VR uses an extended length encoding for explicit transfer syntaxes, false otherwise

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

• dcmdata/include/dcmtk/dcmdata/dcvr.h