A class for managing and converting between different DICOM character sets. More...

Public Member Functions
	DcmSpecificCharacterSet ()
	constructor. More...

	~DcmSpecificCharacterSet ()
	destructor

void	clear ()
	clear the internal state. More...

	operator OFBool () const
	query whether selectCharacterSet() has successfully been called for this object, i.e. whether convertString() may be called. More...

OFBool	operator! () const
	query whether selectCharacterSet() has not been called before, i.e. convertString() would fail. More...

const OFString &	getSourceCharacterSet () const
	get currently selected source DICOM character set(s). More...

const OFString &	getDestinationCharacterSet () const
	get currently selected destination DICOM character set. More...

const OFString &	getDestinationEncoding () const
	get currently selected destination encoding, i.e. the name of the character set as used by the underlying character encoding library for the conversion. More...

unsigned	getConversionFlags () const
	get flags controlling converter behavior, e.g. specifying how illegal character sequences should be handled during conversion. More...

OFCondition	setConversionFlags (const unsigned flags)
	set flags controlling converter behavior, e.g. illegal character sequences should be handled during conversion. More...

OFCondition	selectCharacterSet (const OFString &fromCharset, const OFString &toCharset="ISO_IR 192")
	select DICOM character sets for the input and output string, between which subsequent calls of convertString() convert. More...

OFCondition	selectCharacterSet (DcmItem &dataset, const OFString &toCharset="ISO_IR 192")
	select DICOM character sets for the input and output string, between which subsequent calls of convertString() convert. More...

OFCondition	convertString (const OFString &fromString, OFString &toString, const OFString &delimiters="")
	convert the given string from the selected source character set(s) to the selected destination character set. More...

OFCondition	convertString (const char *fromString, const size_t fromLength, OFString &toString, const OFString &delimiters="")
	convert the given string from the selected source character set(s) to the selected destination character set. More...

Static Public Member Functions
static OFBool	isConversionAvailable ()
	check whether the underlying character set conversion library is available. More...

static size_t	countCharactersInUTF8String (const OFString &utf8String)
	count characters in given UTF-8 string and return the resulting number of so-called "code points". More...

Protected Member Functions
OFCondition	determineDestinationEncoding (const OFString &toCharset)
	determine the destination character encoding (as used by the underlying character encoding library) from the given DICOM defined term (specific character set), and set the member variables accordingly. More...

OFCondition	selectCharacterSetWithoutCodeExtensions ()
	select a particular DICOM character set without code extensions for subsequent conversions. More...

OFCondition	selectCharacterSetWithCodeExtensions (const unsigned long sourceVM)
	select a particular DICOM character set with code extensions for subsequent conversions. More...

OFBool	checkForEscapeCharacter (const char *strValue, const size_t strLength) const
	check whether the given string contains at least one escape character (ESC), because it is used for code extension techniques like ISO 2022 More...

OFString	convertToLengthLimitedOctalString (const char *strValue, const size_t strLength) const
	convert given string to octal format, i.e. all non-ASCII and control characters are converted to their octal representation. More...

Private Types
typedef OFMap< OFString, OFCharacterEncoding >	T_EncodingConvertersMap
	type definition of a map storing the identifier (key) of a character set and the associated character set converter

Private Attributes
OFString	SourceCharacterSet
	selected source character set(s) based on one or more DICOM defined terms

OFString	DestinationCharacterSet
	selected destination character set based on a single DICOM defined term

OFString	DestinationEncoding
	selected destination encoding based on names supported by the underlying character encoding library

OFCharacterEncoding	DefaultEncodingConverter
	character encoding converter

T_EncodingConvertersMap	EncodingConverters
	map of character set conversion descriptors (only used if multiple character sets are needed)

Detailed Description

A class for managing and converting between different DICOM character sets.

The conversion relies on the OFCharacterEncoding class, which again relies on an underlying character encoding library (e.g. libiconv or ICU).

Note: Please note that a current limitation is that only a single value is allowed for the destination character set (i.e. no code extensions). Of course, for the source character set, also multiple values are supported.

Constructor & Destructor Documentation

◆ DcmSpecificCharacterSet()

DcmSpecificCharacterSet::DcmSpecificCharacterSet ( )

constructor.

Initializes the member variables.

Member Function Documentation

◆ checkForEscapeCharacter()

OFBool DcmSpecificCharacterSet::checkForEscapeCharacter	(	const char *	strValue,
		const size_t	strLength
	)		const

protected

check whether the given string contains at least one escape character (ESC), because it is used for code extension techniques like ISO 2022

Parameters

strValue	input string to be checked for any escape character
strLength	length of the input string

Returns: OFTrue if an escape character has been found, OFFalse otherwise

◆ clear()

void DcmSpecificCharacterSet::clear ( )

clear the internal state.

This also forgets about the currently selected character sets, so selectCharacterSet() has to be called again before a string can be converted with convertString().

◆ convertString() [1/2]

OFCondition DcmSpecificCharacterSet::convertString	(	const OFString &	fromString,
		OFString &	toString,
		const OFString &	delimiters = `""`
	)

convert the given string from the selected source character set(s) to the selected destination character set.

That means selectCharacterSet() has to be called prior to this method.

Parameters

fromString	input string to be converted (using the currently selected source character set)
toString	reference to variable where the converted string (using the currently selected destination character set) is stored
delimiters	optional string of characters that are regarded as delimiters, i.e. when found the character set is switched back to the default. CR, LF, FF and HT are always regarded as delimiters (see DICOM PS 3.5).

Returns: status, EC_Normal if successful, an error code otherwise

◆ convertString() [2/2]

OFCondition DcmSpecificCharacterSet::convertString	(	const char *	fromString,
		const size_t	fromLength,
		OFString &	toString,
		const OFString &	delimiters = `""`
	)

convert the given string from the selected source character set(s) to the selected destination character set.

That means selectCharacterSet() has to be called prior to this method. Since the length of the input string has to be specified explicitly, the string can contain more than one NULL byte.

Parameters

fromString	input string to be converted (using the currently selected character set)
fromLength	length of the input string (number of bytes without the trailing NULL byte)
toString	reference to variable where the converted string (using the currently selected destination character set) is stored
delimiters	optional string of characters that are regarded as delimiters, i.e. when found the character set is switched back to the default. CR, LF, FF and HT are always regarded as delimiters (see DICOM PS 3.5).

Returns: status, EC_Normal if successful, an error code otherwise

◆ convertToLengthLimitedOctalString()

OFString DcmSpecificCharacterSet::convertToLengthLimitedOctalString	(	const char *	strValue,
		const size_t	strLength
	)		const

protected

convert given string to octal format, i.e. all non-ASCII and control characters are converted to their octal representation.

The total length of the string is always limited to a particular maximum (see implementation). If the converted string would be longer, it is cropped and "..." is appended to indicate this cropping.

Parameters

strValue	input string to be converted and possibly cropped
strLength	length of the input string

Returns: resulting string in octal format

◆ countCharactersInUTF8String()

static size_t DcmSpecificCharacterSet::countCharactersInUTF8String ( const OFString & utf8String )

static

count characters in given UTF-8 string and return the resulting number of so-called "code points".

Please note that invalid UTF-8 encodings are not handled properly. ASCII strings (7-bit) are also supported, although OFString::length() is probably much faster.

Parameters

utf8String valid character string with UTF-8 encoding

Returns: number of characters (code points) in given UTF-8 string

◆ determineDestinationEncoding()

OFCondition DcmSpecificCharacterSet::determineDestinationEncoding ( const OFString & toCharset )

protected

determine the destination character encoding (as used by the underlying character encoding library) from the given DICOM defined term (specific character set), and set the member variables accordingly.

Parameters

toCharset name of the destination character set used for the output string

Returns: status, EC_Normal if successful, an error code otherwise

◆ getConversionFlags()

unsigned DcmSpecificCharacterSet::getConversionFlags ( ) const

get flags controlling converter behavior, e.g. specifying how illegal character sequences should be handled during conversion.

Note: This method will always return 0 if no encoder was selected using selectEncoding() before calling it.

Returns: a combination the IllegalSequenceMode constants (bitwise or) that is currently set or 0 if the current mode cannot be determined.

◆ getDestinationCharacterSet()

const OFString& DcmSpecificCharacterSet::getDestinationCharacterSet ( ) const

get currently selected destination DICOM character set.

Please note that the returned string, which contains a defined term, is always normalized, i.e. leading and trailing spaces have been removed.

Returns: currently selected destination DICOM character set or an empty string if none is selected (identical to ASCII, which is the default)

◆ getDestinationEncoding()

const OFString& DcmSpecificCharacterSet::getDestinationEncoding ( ) const

get currently selected destination encoding, i.e. the name of the character set as used by the underlying character encoding library for the conversion.

If code extension techniques are used to switch between different character encodings, the main/default encoding is returned.

Returns: currently selected destination encoding or an empty string if none is selected

◆ getSourceCharacterSet()

const OFString& DcmSpecificCharacterSet::getSourceCharacterSet ( ) const

get currently selected source DICOM character set(s).

Please note that the returned string can contain multiple values (defined terms separated by a backslash) if code extension techniques are used. Furthermore, the returned string is always normalized, i.e. leading and trailing spaces have been removed.

Returns: currently selected source DICOM character set(s) or an empty string if none is selected (identical to ASCII, which is the default)

◆ isConversionAvailable()

static OFBool DcmSpecificCharacterSet::isConversionAvailable ( )

static

check whether the underlying character set conversion library is available.

If not, no conversion between different character sets will be possible.

Returns: OFTrue if the character set conversion is available, OFFalse otherwise

◆ operator OFBool()

DcmSpecificCharacterSet::operator OFBool ( ) const

query whether selectCharacterSet() has successfully been called for this object, i.e. whether convertString() may be called.

Returns: OFTrue if selectCharacterSet() was successfully called before, OFFalse if not (or clear() has been called in the meantime).

◆ operator!()

OFBool DcmSpecificCharacterSet::operator! ( ) const

query whether selectCharacterSet() has not been called before, i.e. convertString() would fail.

Returns: OFTrue if selectCharacterSet() must be called before using convertString(), OFFalse if it has already been called.

◆ selectCharacterSet() [1/2]

OFCondition DcmSpecificCharacterSet::selectCharacterSet	(	const OFString &	fromCharset,
		const OFString &	toCharset = `"ISO_IR 192"`
	)

select DICOM character sets for the input and output string, between which subsequent calls of convertString() convert.

The defined terms for a particular character set can be found in the DICOM standard, e.g. "ISO_IR 100" for ISO 8859-1 (Latin 1) or "ISO_IR 192" for Unicode in UTF-8. An empty string denotes the default character repertoire, which is ASCII (7-bit). If multiple values are given for 'fromCharset' (separated by a backslash) code extension techniques are used and escape sequences may be encountered in the source string to switch between the specified character sets.

Parameters

fromCharset	name of the source character set(s) used for the input string as given in the DICOM attribute Specific Character Set (0008,0005). Leading and trailing spaces are removed automatically (if present).
toCharset	name of the destination character set used for the output string. Only a single value is permitted (no code extensions). Leading and trailing spaces are removed automatically (if present). The default value is "ISO_IR 192" (Unicode in UTF-8).

Returns: status, EC_Normal if successful, an error code otherwise

◆ selectCharacterSet() [2/2]

OFCondition DcmSpecificCharacterSet::selectCharacterSet	(	DcmItem &	dataset,
		const OFString &	toCharset = `"ISO_IR 192"`
	)

select DICOM character sets for the input and output string, between which subsequent calls of convertString() convert.

The source character set is determined from the DICOM element Specific Character Set (0008,0005) stored in the given dataset/item. The defined terms for the destination character set can be found in the DICOM standard, e.g. "ISO_IR 100" for ISO 8859-1 (Latin 1) or "ISO_IR 192" for Unicode in UTF-8. An empty string denotes the default character repertoire, which is ASCII (7-bit). If multiple values are found in the Specific Character Set element of the given 'dataset' (separated by a backslash) code extension techniques are used and escape sequences may be encountered in the source string to switch between the specified character sets.

Parameters

dataset	DICOM dataset or item from which the source character set should be retrieved. If the data element Specific Character Set (0008,0005) is empty or missing, the default character set (i.e. ASCII) is used.
toCharset	name of the destination character set used for the the output string. Only a single value is permitted (no code extensions). Leading and trailing spaces are removed automatically (if present). The default value is "ISO_IR 192" (Unicode in UTF-8).

Returns: status, EC_Normal if successful, an error code otherwise

◆ selectCharacterSetWithCodeExtensions()

OFCondition DcmSpecificCharacterSet::selectCharacterSetWithCodeExtensions ( const unsigned long sourceVM )

protected

select a particular DICOM character set with code extensions for subsequent conversions.

The corresponding DICOM defined terms for the source character set are determined from the member variable 'SourceCharacterSet'.

Parameters

sourceVM value multiplicity of the member variable 'SourceCharacterSet'. Usually, this value has already been determined by the calling method.

Returns: status, EC_Normal if successful, an error code otherwise

◆ selectCharacterSetWithoutCodeExtensions()

OFCondition DcmSpecificCharacterSet::selectCharacterSetWithoutCodeExtensions ( )

protected

select a particular DICOM character set without code extensions for subsequent conversions.

The corresponding DICOM defined term for the source character set is determined from the member variable 'SourceCharacterSet'.

Returns: status, EC_Normal if successful, an error code otherwise

◆ setConversionFlags()

OFCondition DcmSpecificCharacterSet::setConversionFlags ( const unsigned flags )

set flags controlling converter behavior, e.g. illegal character sequences should be handled during conversion.

Precondition: An encoding has been selected by successfully calling OFCharacterEncoding::selectEncoding(), i.e. OFCharacterEncoding::isLibraryAvailable() and *this evaluate to OFTrue.

Parameters

flags the conversion flags that shall be used, a combination of the OFCharacterEncoding::ConversionFlags constants, e.g. TransliterateIllegalSequences | DiscardIllegalSequences.

Returns: EC_Normal if the flags were set, an error code otherwise, i.e. if the flags are not supported by the underlying implementation.

See also: OFCharacterEncoding::supportsConversionFlags()

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

dcmdata/include/dcmtk/dcmdata/dcspchrs.h

Public Member Functions

Static Public Member Functions

Protected Member Functions

Private Types

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ DcmSpecificCharacterSet()

Member Function Documentation

◆ checkForEscapeCharacter()

◆ clear()

◆ convertString() [1/2]

◆ convertString() [2/2]

◆ convertToLengthLimitedOctalString()

◆ countCharactersInUTF8String()

◆ determineDestinationEncoding()

◆ getConversionFlags()

◆ getDestinationCharacterSet()

◆ getDestinationEncoding()

◆ getSourceCharacterSet()

◆ isConversionAvailable()

◆ operator OFBool()

◆ operator!()

◆ selectCharacterSet() [1/2]

◆ selectCharacterSet() [2/2]

◆ selectCharacterSetWithCodeExtensions()

◆ selectCharacterSetWithoutCodeExtensions()

◆ setConversionFlags()