API documentation

DCM_CAPACITY_AE

Maximum number of characters in values with Value Representation AE.

DCM_CAPACITY_AS

Maximum number of characters in values with Value Representation AS.

DCM_CAPACITY_AT

Maximum number of characters in values with Value Representation AT.

DCM_CAPACITY_CS

Maximum number of characters in values with Value Representation CS.

DCM_CAPACITY_DA

Maximum number of characters in values with Value Representation DA.

DCM_CAPACITY_DS

Maximum number of characters in values with Value Representation DS.

DCM_CAPACITY_DT

Maximum number of characters in values with Value Representation DT.

DCM_CAPACITY_IS

Maximum number of characters in values with Value Representation IS.

DCM_CAPACITY_LO

Maximum number of characters in values with Value Representation LO.

DCM_CAPACITY_LT

Maximum number of characters in values with Value Representation LT.

DCM_CAPACITY_PN

Maximum number of characters in values with Value Representation PN.

DCM_CAPACITY_SH

Maximum number of characters in values with Value Representation SH.

DCM_CAPACITY_ST

Maximum number of characters in values with Value Representation ST.

DCM_CAPACITY_TM

Maximum number of characters in values with Value Representation TM.

DCM_CAPACITY_UC

Maximum number of characters in values with Value Representation UC.

DCM_CAPACITY_UI

Maximum number of characters in values with Value Representation UI.

DCM_CAPACITY_UR

Maximum number of characters in values with Value Representation UR.

DCM_CAPACITY_UT

Maximum number of characters in values with Value Representation UT.

void dcm_init(void)

Start up libdicom.

Call this from the main thread during program startup for libdicom to be threadsafe.

If you don’t do this, libdicom will attempt to call it for you in a safe way, but cannot guarantee this on all platforms and with all compilers, and therefore cannot guarantee thread safety.

This function can be called many times.

type DcmError

Error return object.

enum _DcmErrorCode

Enumeration of error codes.

enumerator DCM_ERROR_CODE_NOMEM = 1

Out of memory

enumerator DCM_ERROR_CODE_INVALID = 2

Invalid parameter

enumerator DCM_ERROR_CODE_PARSE = 3

Parse error

enumerator DCM_ERROR_CODE_IO = 4

IO error

enumerator DCM_ERROR_CODE_MISSING_FRAME = 5

Missing frame

const char *dcm_error_code_str(DcmErrorCode code)

Convert an error code to a human-readable string.

Parameters:
  • code – The error code

Returns:

A string that can be displayed to users

const char *dcm_error_code_name(DcmErrorCode code)

Get a symbolic name for a DcmErrorCode.

Parameters:
  • code – The error code

Returns:

A symbolic name for the code.

void dcm_error_set(DcmError **error, DcmErrorCode code, const char *summary, const char *format, ...)

Set an error.

Create a new DcmError object and store the pointer in error.

You can’t set error twice – always check the error state and return immediately if set.

Parameters:
  • error – Pointer to store the new error object in

  • code – Numeric error code

  • summary – Summary of error

  • format – printf-style format string

  • ... – Format string arguments

void dcm_error_clear(DcmError **error)

Clear an error, if set.

Parameters:
  • error – Pointer holding the error object

const char *dcm_error_get_summary(DcmError *error)

Get a summary of the error.

Do not free this result. The pointer will be valid as long as error is valid.

Parameters:
  • error – DcmError to read the error from

Returns:

Short description of the error

const char *dcm_error_get_message(DcmError *error)

Get the error message.

Do not free this result. The pointer will be valid as long as error is valid.

Parameters:
  • error – Error object

Returns:

Message stored in a error object

DcmErrorCode dcm_error_get_code(DcmError *error)

Get the error code.

Parameters:
  • error – Error object

Returns:

Error code

void dcm_error_log(DcmError *error)

Log an error message using information stored on the error object.

Parameters:
  • error – Error object

void dcm_error_print(DcmError *error)

Print an error message to stderr.

Parameters:
  • error – Error object

void dcm_free(void *pointer)

Free an allocated memory area.

Any memory allocated by libdicom and returned to the calling program should be freed with this.

Parameters:
  • pointer – Memory area to free

void *dcm_calloc(DcmError **error, int n, int size)

Allocate and zero an area of memory.

Any memory which you pass to libdicom and which you ask libdicom to manage with a “steal” flag should be allcoatyed with one of the libdicom memory allocators.

Parameters:
  • error – Pointer to error object

  • n – Number of items to allocate

  • size – Size of each item in bytes

Returns:

Pointer to memory area

enum _DcmLogLevel

Enumeration of log levels

enumerator DCM_LOG_CRITICAL = 50

Critical

enumerator DCM_LOG_ERROR = 40

Error

enumerator DCM_LOG_WARNING = 30

Warning

enumerator DCM_LOG_INFO = 20

Info

enumerator DCM_LOG_DEBUG = 10

Debug

enumerator DCM_LOG_NOTSET = 0

Not set (no logging)

DcmLogLevel dcm_log_set_level(DcmLogLevel log_level)

Set the log level.

Parameters:
  • log_level – New log level.

Returns:

previous log level

type DcmLogf

Log function. See dcm_log_set_logf().

DcmLogf dcm_log_set_logf(DcmLogf logf)

Set the log function.

This function will be used to log any error or warning messages from the library. The default DcmLogf function prints messages to stderr. Set to NULL to disable all logging.

Parameters:
  • logf – New log function.

Returns:

previous log function

void dcm_log_critical(const char *format, ...)

Write critical log message to stderr stream.

Parameters:
  • format – printf-style format string

  • ... – Format string arguments

void dcm_log_error(const char *format, ...)

Write error log message to stderr stream.

Parameters:
  • format – printf-style format string

  • ... – Format string arguments

void dcm_log_warning(const char *format, ...)

Write warning log message to stderr stream.

Parameters:
  • format – printf-style format string

  • ... – Format string arguments

void dcm_log_info(const char *format, ...)

Write info log message to stderr stream.

Parameters:
  • format – printf-style format string

  • ... – Format string arguments

void dcm_log_debug(const char *format, ...)

Write debug log message to stderr stream.

Parameters:
  • format – printf-style format string

  • ... – Format string arguments

const char *dcm_get_version(void)

Get the version of the library.

Returns:

semantic version string

enum _DcmVR

An enum of Value Representations.

Value Representations which are not known to libdicom will be coded as DCM_VR_ERROR (unknown Value Representation).

Note to maintainers: this enum must match the table in dicom-dict.c, and the DcmVRTag enum. As the DICOM standard evolves, numbering must be maintained for ABI compatibility.

enum _DcmVRClass

The general class of the value associated with a Value Representation.

DCM_VR_CLASS_STRING_MULTI – one or more null-terminated strings, cannot contain backslash

DCM_VR_CLASS_STRING_SINGLE – a single null-terminated string, backslash allowed

DCM_VR_CLASS_NUMERIC_DECIMAL – one or more binary floating point numeric values, other fields give sizeof(type)

DCM_VR_CLASS_NUMERIC_INTEGER – one or more binary integer numeric values, other fields give sizeof(type)

DCM_VR_CLASS_BINARY – an uninterpreted array of bytes, length in the element header

DCM_VR_CLASS_SEQUENCE – Value Representation is a sequence

DcmVRClass dcm_dict_vr_class(DcmVR vr)

Find the general class for a particular Value Representation.

Parameters:
  • vr – The Value Representation

Returns:

The general class of that Value Representation

DcmVR dcm_dict_vr_from_str(const char *vr)

Turn a string Value Representation into an enum value.

Parameters:
  • vr – The Value Representation as a two character string.

Returns:

the enum for that Value Representation

const char *dcm_dict_str_from_vr(DcmVR vr)

Turn an enum Value Representation into a character string.

Parameters:
  • vr – The Value Representation as an enum value.

Returns:

the string representation of that Value Representation, or NULL

const char *dcm_dict_keyword_from_tag(int tag)

Look up the Keyword of an Attribute in the Dictionary.

Returns NULL if the tag is not recognised.

Parameters:
  • tag – Attribute Tag

Returns:

attribute Keyword

int dcm_dict_tag_from_keyword(void)

Look up the tag of an Attribute in the Dictionary.

Returns 0xffffffff if the keyword is not recognised.

Parameters:
  • tag – Attribute keyword

Returns:

attribute tag

DcmVR dcm_vr_from_tag(int tag)

Find the Value Representation for a tag.

This will return DCM_VR_ERROR if the tag is unknown, or does not have a unique Value Representation.

Parameters:
  • tag – Attribute Tag

Returns:

the unique Value Representation for this tag, or DCM_VR_ERROR

_Bool dcm_is_public_tag(int tag)

Determine whether a Tag is public.

A Tag is public if it is defined in the Dictionary.

Parameters:
  • tag – Attribute Tag

Returns:

Yes/no answer

_Bool dcm_is_private_tag(int tag)

Determine whether a Tag is private.

Parameters:
  • tag – Attribute Tag

Returns:

Yes/no answer

_Bool dcm_is_valid_tag(int tag)

Determine whether a Tag is valid.

Parameters:
  • tag – Attribute Tag

Returns:

Yes/no answer

_Bool dcm_is_valid_vr(const char *vr)

Determine whether a Value Representation is valid.

Parameters:
  • vr – Attribute Value Representation

Returns:

Yes/no answer

_Bool dcm_is_valid_vr_for_tag(DcmVR vr, int tag)

Determine whether a Value Representation is valid.

Parameters:
  • vr – Attribute Value Representation

Returns:

Yes/no answer

_Bool dcm_is_encapsulated_transfer_syntax(const char *transfer_syntax_uid)

Determine whether a Transfer Syntax is encapsulated.

Parameters:
  • transfer_syntax_uid – Transfer Syntax UID

Returns:

Yes/no answer

type DcmElement

Data Element.

DcmElement *dcm_element_create(DcmError **error, int tag, DcmVR vr)

Create a Data Element for a tag.

After creating a Data Element, you must attach an appropriate value using one of the setting functions. See for example dcm_element_set_value_string().

Parameters:
  • error – Pointer to error object

  • tag – Tag

  • vr – The Value Representation for this Data Element

Returns:

Pointer to Data Element

int dcm_element_get_group_number(void)

Get group number (first part of Tag) of a Data Element.

Parameters:
  • element – Pointer to Data Element

Returns:

Tag group number

int dcm_element_get_element_number(void)

Get Element Number (second part of Tag) of a Data Element.

Parameters:
  • element – Pointer to Data Element

Returns:

Tag Element Number

int dcm_element_get_tag(void)

Get Tag of a Data Element.

Parameters:
  • element – Pointer to Data Element

Returns:

Tag

DcmVR dcm_element_get_vr(const DcmElement *element)

Get the Value Representation of a Data Element.

Parameters:
  • element – Pointer to Data Element

Returns:

Value Representation

int dcm_element_get_length(void)

Get length of the entire value of a Data Element.

Parameters:
  • element – Pointer to Data Element

Returns:

Length of value of Data Element

int dcm_element_get_vm(void)

Get Value Multiplicity of a Data Element.

Parameters:
  • element – Pointer to Data Element

Returns:

Value Multiplicity

_Bool dcm_element_is_multivalued(const DcmElement *element)

Determine whether a Data Element has a Value Multiplicity greater than one.

Parameters:
  • element – Pointer to Data Element

Returns:

Yes/no answer

DcmElement *dcm_element_clone(DcmError **error, const DcmElement *element)

Clone (i.e., create a deep copy of) a Data Element.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

Returns:

Pointer to clone of Data Element

_Bool dcm_element_get_value_string(DcmError **error, const DcmElement *element, int index, const char **value)

Get a string from a string-valued Data Element.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • index – Zero-based index of value within the Data Element

  • value – Pointer to return location for value

Returns:

true on success

_Bool dcm_element_set_value_string(DcmError **error, DcmElement *element, char *value, _Bool steal)

Set the value of a Data Element to a character string.

The Data Element must have a Tag that allows for a character string Value Representation. If that is not the case, the function will fail.

On success, if steal is true, ownership of value passes to element, i.e. it will be freed when element is destroyed. If steal is false, then a copy is made of value and ownership is not transferred.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • value – String value

  • steal – if true, ownership of value passes to element

Returns:

true on success

_Bool dcm_element_set_value_string_multi(DcmError **error, DcmElement *element, char **values, int vm, _Bool steal)

Set the value of a Data Element to an array of character strings.

The Data Element must have a Tag that allows for a character string Value Representation and for a Value Multiplicity greater than one. If that is not the case, the function will fail.

On success, if steal is true, ownership of value passes to element, i.e. it will be freed when element is destroyed. If steal is false, then a copy is made of value and ownership is not transferred.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • values – Pointer to memory location where values are written to

  • vm – Number of values

  • steal – if true, ownership of values passes to element

Returns:

true on success

_Bool dcm_element_get_value_integer(DcmError **error, const DcmElement *element, int index, int *value)

Get an integer from a 16, 32 or 64-bit integer-valued Data Element.

The integer held in the Element will be cast to int64_t for return.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • index – Zero-based index of value within the Data Element

  • value – Pointer to return location for value

Returns:

true on success

_Bool dcm_element_set_value_integer(DcmError **error, DcmElement *element, int value)

Set the value of a Data Element to an integer.

The Data Element must have a Tag that allows for a integer Value Representation. If that is not the case, the function will fail.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • value – Integer value

Returns:

true on success

_Bool dcm_element_set_value_numeric_multi(DcmError **error, DcmElement *element, void *values, int vm, _Bool steal)

Set the value of a Data Element to a number.

The Data Element must have a Tag that allows for a numeric Value Representation. If that is not the case, the function will fail.

Although the value passed is void*, it should be a pointer to an array of 16- to 64-bit numeric values of the appropriate type for the Data Element Value Representation.

On success, if steal is true, ownership of values passes to element, i.e. it will be freed when element is destroyed. If steal is false, then a copy is made of values and ownership is not transferred.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • values – Array of values

  • vm – Number of values

  • steal – if true, ownership of values passes to element

Returns:

true on success

_Bool dcm_element_get_value_decimal(DcmError **error, const DcmElement *element, int index, double *value)

Get a floating-point value from a Data Element.

The Data Element Value Reepresentation may be either single- or double-precision floating point.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • index – Zero-based index of value within the Data Element

  • value – Pointer to return location for value

Returns:

true on success

_Bool dcm_element_set_value_decimal(DcmError **error, DcmElement *element, double value)

Set the value of a Data Element to a floating-point.

The Data Element must have a Tag that allows for a floating-point Value Representation. If that is not the case, the function will fail.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • value – Floating point value

Returns:

true on success

_Bool dcm_element_get_value_binary(DcmError **error, const DcmElement *element, const void **value)

Get a binary value from a Data Element.

Use dcm_element_length() to get the length of the binary value.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • value – Pointer to return location for value

Returns:

true on success

_Bool dcm_element_set_value_binary(DcmError **error, DcmElement *element, void *value, int length, _Bool steal)

Set the value of a Data Element to binary data.

The Data Element must have a Tag that allows for a binary Value Representation. If that is not the case, the function will fail.

On success, if steal is true, ownership of value passes to element, i.e. it will be freed when element is destroyed. If steal is false, then a copy is made of value and ownership is not transferred.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • value – Pointer to binary value

  • length – Length in bytes of the binary value

  • steal – if true, ownership of the value passes to element

Returns:

true on success

_Bool dcm_element_get_value_sequence(DcmError **error, const DcmElement *element, DcmSequence **value)

Get a sequence value from a Data Element.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • value – Pointer to return location for value

Returns:

true on success

_Bool dcm_element_set_value_sequence(DcmError **error, DcmElement *element, DcmSequence *value)

Set the value of a Data Element to a Sequence.

The Data Element must have a Tag that allows for Value Representation "SQ". If that is not the case, the function will fail.

The Data Element takes ownership of the value pointer on success.

Parameters:
  • error – Pointer to error object

  • element – Pointer to Data Element

  • value – Pointer to Sequence

Returns:

true on success

char *dcm_element_value_to_string(const DcmElement *element)

Make a string suitable for display to a user from the value of an element.

The return result must be freed with free(). The result may be NULL.

Returns:

string to display

void dcm_element_print(const DcmElement *element, int indentation)

Print a Data Element.

Parameters:
  • element – Pointer to Data Element

  • indentation – Number of white spaces before text

void dcm_element_destroy(DcmElement *element)

Destroy a Data Element.

Parameters:
  • element – Pointer to Data Element

type DcmDataSet

Data Set

DcmDataSet *dcm_dataset_create(DcmError **error)

Create an empty Data Set.

Parameters:
  • error – Pointer to error object

DcmDataSet *dcm_dataset_clone(DcmError **error, const DcmDataSet *dataset)

Clone (i.e., create a deep copy of) a Data Set.

Parameters:
  • error – Pointer to error object

  • dataset – Pointer to Data Set

Returns:

Pointer to clone of Data Set

_Bool dcm_dataset_insert(DcmError **error, DcmDataSet *dataset, DcmElement *element)

Insert a Data Element into a Data Set.

Parameters:
  • error – Pointer to error object

  • dataset – Pointer to Data Set

  • element – Pointer to Data Element

The object takes over ownership of the memory referenced by element and frees it when the object is destroyed or if the insert operation fails.

Returns:

Whether insert operation was successful

_Bool dcm_dataset_remove(DcmError **error, DcmDataSet *dataset, int tag)

Remove a Data Element from a Data Set.

Parameters:
  • error – Pointer to error object

  • dataset – Pointer to Data Set

  • tag – Attribute Tag of a Data Element

Returns:

Whether remove operation was successful

DcmElement *dcm_dataset_get(DcmError **error, const DcmDataSet *dataset, int tag)

Get a Data Element from a Data Set.

Parameters:
  • error – Pointer to error object

  • dataset – Pointer to Data Set

  • tag – Attribute Tag of a Data Element

Returns:

Pointer to Data Element

DcmElement *dcm_dataset_get_clone(DcmError **error, const DcmDataSet *dataset, int tag)

Get a clone (deep copy) of a Data Element from a Data Set.

Parameters:
  • error – Pointer to error object

  • dataset – Pointer to Data Set

  • tag – Attribute Tag of a Data Element

Returns:

Pointer to clone of Data Element

_Bool dcm_dataset_foreach(const DcmDataSet *dataset, _Bool (*fn)(const DcmElement *element, void *client), void *client)

Iterate over Data Elements in a Data Set.

The user function should return true to continue looping, or false to terminate the loop early.

The result is true if the whole Data Set returned true, or false if one call requested early termination.

The function must not modify the Data Set.

Parameters:
  • seq – Pointer to Data Set

  • fn – Pointer to function that should be called for each Data Element

  • client – Client data for function

Returns:

true if all functions return true

DcmElement *dcm_dataset_contains(const DcmDataSet *dataset, int tag)

Fetch a Data Element from a Data Set, or NULL if not present.

Parameters:
  • dataset – Pointer to Data Set

  • tag – Attribute Tag of a Data Element

Returns:

Data Element, or NULL if not present

int dcm_dataset_count(void)

Count the number of Data Elements in a Data Set.

Parameters:
  • dataset – Pointer to Data Set

Returns:

Number of Data Elements

void dcm_dataset_copy_tags(const DcmDataSet *dataset, int *tags, int n)

Obtain a copy of the Tag of each Data Element in a Data Set.

The tags will be sorted in ascending order.

Parameters:
  • dataset – Pointer to Data Set

  • tags – Pointer to memory location to of the array into which to copy tags. Number of items in the array must match the number of Data Elements in the Data Set as determined by dcm_dataset_count().

  • n – Number of items in the array.

Ownership of the memory allocated for tags remains with the caller. Specifically, the function does not free the memory allocated for tags if the copy operation fails.

void dcm_dataset_lock(DcmDataSet *dataset)

Lock a Data Set to prevent modification.

Parameters:
  • dataset – Pointer to Data Set

_Bool dcm_dataset_is_locked(const DcmDataSet *dataset)

Check whether a Data Set is locked.

Parameters:
  • dataset – Pointer to Data Set

Returns:

Yes/no answer

void dcm_dataset_print(const DcmDataSet *dataset, int indentation)

Print a Data Set.

Parameters:
  • error – Pointer to error object

  • dataset – Pointer to Data Set

  • indentation – Number of white spaces before text

void dcm_dataset_destroy(DcmDataSet *dataset)

Destroy a Data Set.

Parameters:
  • dataset – Pointer to Data Set

Sequence

DcmSequence *dcm_sequence_create(DcmError **error)

Create a Sequence, i.e., an ordered list of Data Set items that represent the value of a Data Element with Value Representation SQ (Sequence).

Note that created object represents the value of a Data Element rather than a Data Element itself.

Parameters:
  • error – Pointer to error object

Returns:

Pointer to Sequence

_Bool dcm_sequence_append(DcmError **error, DcmSequence *seq, DcmDataSet *item)

Append a Data Set item to a Sequence.

Parameters:
  • error – Pointer to error object

  • seq – Pointer to Sequence

  • item – Data Set item

The object takes over ownership of the memory referenced by item and frees it when the object is destroyed or if the append operation fails.

Returns:

Whether append operation was successful

DcmDataSet *dcm_sequence_get(DcmError **error, const DcmSequence *seq, int index)

Get a Data Set item from a Sequence.

Parameters:
  • error – Pointer to error object

  • seq – Pointer to Sequence

  • index – Zero-based index of the Data Set item in the Sequence

Returns:

Pointer to Data Set item

_Bool dcm_sequence_foreach(const DcmSequence *seq, _Bool (*fn)(const DcmDataSet *dataset, int index, void *client), void *client)

Iterate over Data Sets in a Sequence.

The user function should return true to continue looping, or false to terminate the loop early.

The result is true if the whole sequence returned true, or false if one call requested early termination.

The function must not modify the seqeucence.

Parameters:
  • seq – Pointer to Sequence

  • fn – Pointer to function that should be called for each Data Set

  • client – Client data for function

Returns:

Pointer to Data Set item

_Bool dcm_sequence_remove(DcmError **error, DcmSequence *seq, int index)

Remove a Data Set item from a Sequence.

Parameters:
  • error – Pointer to error object

  • seq – Pointer to Sequence

  • index – Zero-based index of the Data Set item in the Sequence

Returns:

Whether remove operation was successful

int dcm_sequence_count(void)

Count the number of Data Set items in a Sequence.

Parameters:
  • seq – Pointer to Sequence

Returns:

number of Data Set items

void dcm_sequence_lock(DcmSequence *seq)

Lock a Sequence to prevent modification.

Parameters:
  • seq – Pointer to Sequence

_Bool dcm_sequence_is_locked(const DcmSequence *seq)

Check whether a Sequence is locked.

Parameters:
  • seq – Pointer to Sequence

Returns:

Yes/no answer

void dcm_sequence_destroy(DcmSequence *seq)

Destroy a Sequence.

Parameters:
  • seq – Pointer to Sequence

type DcmFrame

Frame Item of Pixel Data Element

Encoded pixels of an individual pixel matrix and associated descriptive metadata.

DcmFrame *dcm_frame_create(DcmError **error, int number, const char *data, int length, int rows, int columns, int samples_per_pixel, int bits_allocated, int bits_stored, int pixel_representation, int planar_configuration, const char *photometric_interpretation, const char *transfer_syntax_uid)

Create a Frame.

Parameters:
  • error – Pointer to error object

  • index – Index of the Frame within the Pixel Data Element

  • data – Pixel data of the Frame

  • length – Size of the Frame (number of bytes)

  • rows – Number of rows in pixel matrix

  • columns – Number of columns in pixel matrix

  • samples_per_pixel – Number of samples per pixel

  • bits_allocated – Number of bits allocated per pixel

  • bits_stored – Number of bits stored per pixel

  • pixel_representation – Representation of pixels (unsigned integers or 2’s complement)

  • planar_configuration – Configuration of samples (color-by-plane or color-by-pixel)

  • photometric_interpretation – Interpretation of pixels (monochrome, RGB, etc.)

  • transfer_syntax_uid – UID of transfer syntax in which data is encoded

The object takes over ownership of the memory referenced by data, photometric_interpretation, and transfer_syntax_uid and frees it when the object is destroyed or if the creation fails.

Returns:

Frame Item

int dcm_frame_get_number(void)

Get number of a Frame Item within the Pixel Data Element.

Parameters:
  • frame – Frame

Returns:

number (one-based index)

int dcm_frame_get_length(void)

Get length of a Frame Item.

Parameters:
  • frame – Frame

Returns:

number of bytes

int dcm_frame_get_rows(void)

Get Rows of a Frame.

Parameters:
  • frame – Frame

Returns:

number of rows in pixel matrix

int dcm_frame_get_columns(void)

Get Columns of a Frame.

Parameters:
  • frame – Frame

Returns:

number of columns in pixel matrix

int dcm_frame_get_samples_per_pixel(void)

Get Samples per Pixel of a Frame.

Parameters:
  • frame – Frame

Returns:

number of samples (color channels) per pixel

int dcm_frame_get_bits_allocated(void)

Get Bits Allocated of a Frame.

Parameters:
  • frame – Frame

Returns:

number of bits allocated per pixel

int dcm_frame_get_bits_stored(void)

Get Bits Stored of a Frame.

Parameters:
  • frame – Frame

Returns:

number of bits stored per pixel

int dcm_frame_get_high_bit(void)

Get High Bit of a Frame.

Parameters:
  • frame – Frame

Returns:

most significant bit of pixels

int dcm_frame_get_pixel_representation(void)

Get Pixel Representation of a Frame.

Parameters:
  • frame – Frame

Returns:

representation of pixels (unsigned integers or 2’s complement)

int dcm_frame_get_planar_configuration(void)

Get Planar Configuration of a Frame.

Parameters:
  • frame – Frame

Returns:

configuration of samples (color-by-plane or color-by-pixel)

const char *dcm_frame_get_photometric_interpretation(const DcmFrame *frame)

Get Photometric Interpretation of a Frame.

Parameters:
  • frame – Frame

Returns:

interpretation of pixels (monochrome, RGB, etc.)

const char *dcm_frame_get_transfer_syntax_uid(const DcmFrame *frame)

Get Transfer Syntax UID for a Frame.

Parameters:
  • frame – Frame

Returns:

UID of the transfer syntax in which frame is encoded

const char *dcm_frame_get_value(const DcmFrame *frame)

Get pixel data of a Frame.

Parameters:
  • frame – Frame

Returns:

pixel data

void dcm_frame_destroy(DcmFrame *frame)

Destroy a Frame.

Parameters:
  • frame – Frame

type DcmFilehandle

Part 10 File

struct _DcmIO

An object we can read from.

struct _DcmIOMethods

Seek an IO object, semantics as POSIX seek()

DcmIO *(*open)(DcmError **error, void *client)

Open an IO object

void (*close)(DcmIO *io)

Close an IO object

DcmIO *dcm_io_create(DcmError **error, const DcmIOMethods *methods, void *client)

Create an IO object using a set of IO methods.

Parameters:
  • error – Error structure pointer

  • io – Set of read methods

  • client – Client data for read methods

Returns:

IO object

DcmIO *dcm_io_create_from_file(DcmError **error, const char *filename)

Open a file on disk for IO.

Parameters:
  • error – Error structure pointer

  • filename – Path to the file on disk

Returns:

IO object

DcmIO *dcm_io_create_from_memory(DcmError **error, const char *buffer, int length)

Open an area of memory for IO.

Parameters:
  • error – Error structure pointer

  • buffer – Pointer to memory area

  • length – Length of memory area in bytes

Returns:

IO object

void dcm_io_close(DcmIO *io)

Close an IO object.

Parameters:
  • io – Pointer to IO object

int dcm_io_read(void)

Read from an IO object.

Read up to length bytes from the IO object. Returns the number of bytes read, or -1 for an error. A return of 0 indicates end of file.

Parameters:
  • error – Pointer to error object

  • io – Pointer to IO object

  • buffer – Memory area to read to

  • length – Size of memory area

Returns:

Number of bytes read

int dcm_io_seek(void)

Seek an IO object.

Set whence to SEEK_CUR to seek relative to the current file position, SEEK_END to seek relative to the end of the file, or SEEK_SET to seek relative to the start.

Returns the new absolute read position, or -1 for IO error.

Parameters:
  • error – Error structure pointer

  • io – Pointer to IO object

  • offset – Seek offset

  • whence – Seek mode

Returns:

New read position

DcmFilehandle *dcm_filehandle_create(DcmError **error, DcmIO *io)

Create a representation of a DICOM File using an IO object.

The File object tracks information like the transfer syntax and the byte ordering.

Parameters:
  • error – Error structure pointer

  • io – IO object to read from

Returns:

filehandle

DcmFilehandle *dcm_filehandle_create_from_file(DcmError **error, const char *filepath)

Open a file on disk as a DcmFilehandle.

Parameters:
  • error – Error structure pointer

  • filepath – Path to the file on disk

Returns:

filehandle

DcmFilehandle *dcm_filehandle_create_from_memory(DcmError **error, const char *buffer, int length)

Open an area of memory as a DcmFilehandle.

Parameters:
  • error – Error structure pointer

  • buffer – Pointer to memory area

  • length – Length of memory area in bytes

Returns:

filehandle

void dcm_filehandle_destroy(DcmFilehandle *filehandle)

Destroy a Filehandle.

Parameters:
  • filehandle – File

const DcmDataSet *dcm_filehandle_get_file_meta(DcmError **error, DcmFilehandle *filehandle)

Get File Meta Information from a File.

Reads the File Meta Information and saves it in the File handle. Returns a reference to this internal copy of the File Meta Information.

The return result must not be destroyed. Make a clone of it with dcm_dataset_clone() if you need it to remain valid after closing the File handle.

After calling this function, the filehandle read point is always positioned at the start of the File metadata.

It is safe to call this function many times.

Parameters:
  • error – Pointer to error object

  • filehandle – Pointer to file handle

Returns:

File Meta Information

const char *dcm_filehandle_get_transfer_syntax_uid(const DcmFilehandle *filehandle)

Get Transfer Syntax UID for a fileahndle.

Parameters:
  • filehandle – File

Returns:

UID of the transfer syntax for this File.

DcmDataSet *dcm_filehandle_read_metadata(DcmError **error, DcmFilehandle *filehandle, const int *stop_tags)

Read metadata from a File.

Read slide metadata, stopping when one of the tags in the stop list is seen. If the stop list pointer is NULL, it will stop on any of the pixel data tags.

The return result must be destroyed with dcm_dataset_destroy().

After calling this function, the filehandle read point is always positioned at the tag that stopped the read. You can call this function again with a different stop set to read more of the metadata.

Parameters:
  • error – Pointer to error object

  • filehandle – File

  • stop_tags – NULL, or Zero-terminated array of tags to stop on

Returns:

metadata

const DcmDataSet *dcm_filehandle_get_metadata_subset(DcmError **error, DcmFilehandle *filehandle)

Get a fast subset of metadata from a File.

Gets a subset of the File’s metadata and saves it in the File handle. Returns a reference to this internal copy of the File metadata.

The subset is the part of the DICOM metadata that can be read quickly. It is missing tags such as PerFrameFunctionalGroupSequence. Use dcm_filehandle_read_metadata() if you need all file metadata.

The return result must not be destroyed. Make a clone of it with dcm_dataset_clone() if you need it to remain valid after closing the File handle.

After calling this function, the filehandle read point is always positioned at the tag that stopped the read.

It is safe to call this function many times.

Parameters:
  • error – Pointer to error object

  • filehandle – File

Returns:

metadata

_Bool dcm_filehandle_prepare_read_frame(DcmError **error, DcmFilehandle *filehandle)

Read everything necessary to fetch frames from the file.

Scans the PixelData sequence and loads the PerFrameFunctionalGroupSequence, if present.

This function will be called automatically on the first call to dcm_filehandle_read_frame_position() or dcm_filehandle_read_frame(). It can take some time to execute, so it is available as a separate function call in case this delay needs to be managed.

After calling this function, the filehandle read point is always positioned at the PixelData tag.

It is safe to call this function many times.

Parameters:
  • error – Pointer to error object

  • filehandle – File

Returns:

true on success

DcmFrame *dcm_filehandle_read_frame(DcmError **error, DcmFilehandle *filehandle, int frame_number)

Read an individual Frame from a File.

Frames are numbered from 1 in the order they appear in the PixelData element.

Parameters:
  • error – Pointer to error object

  • filehandle – File

  • index – One-based frame number

Returns:

Frame

DcmFrame *dcm_filehandle_read_frame_position(DcmError **error, DcmFilehandle *filehandle, int column, int row)

Read the frame at a position in a File.

Read a frame from a File at a specified (column, row), numbered from zero. This takes account of any frame positioning given in PerFrameFunctionalGroupSequence.

If the frame is missing, perhaps because this is a sparse file, this function returns NULL and sets the error DCM_ERROR_CODE_MISSING_FRAME. Applications can detect this and render a background image.

Parameters:
  • error – Pointer to error object

  • filehandle – File

  • column – Column number, from 0

  • row – Row number, from 0

Returns:

Frame

_Bool dcm_filehandle_print(DcmError **error, DcmFilehandle *filehandle)

Scan a file and print the entire structure to stdout.

Parameters:
  • error – Pointer to error object

  • filehandle – File

Returns:

true on successful parse, false otherwise.