celantur::ExifMetadata Struct Reference

Structure to manage EXIF metadata for images. This structure encapsulates EXIF data and provides methods to manipulate and retrieve information from it. It is used in conjunction with JPEG encoding and decoding functions to preserve image metadata. More...

#include <ImageEncoding.h>

Public Member Functions
	ExifMetadata (ExifData *data)
	Constructor that takes ownership of an ExifData pointer. More...
	~ExifMetadata ()
	ExifMetadata (const ExifMetadata &)=delete
ExifMetadata &	operator= (const ExifMetadata &)=delete
	ExifMetadata (ExifMetadata &&other) noexcept
	Move constructor. More...
ExifMetadata &	operator= (ExifMetadata &&other) noexcept
	Move assignment operator. More...
void	print_exif_entry (ExifEntry *entry, std::ostream &oss) const
	Print the EXIF metadata to the provided output stream. This function outputs the EXIF metadata in a human-readable format, useful for debugging and. More...
void	print_exif_content (ExifContent *content, std::ostream &oss) const
	Print the contents of an ExifContent structure to the provided output stream. This function iterates through all entries in the ExifContent and prints their details. More...
int	get_orientation () const
	Retrieve the orientation value from the EXIF metadata. This function extracts the orientation tag from the EXIF data, which indicates how the image should be rotated for correct display. More...

Public Attributes
ExifData *	metadata {nullptr}
	Pointer to the underlying ExifData structure. This pointer is managed by the ExifMetadata instance and should not be accessed directly. More...

Detailed Description

Structure to manage EXIF metadata for images. This structure encapsulates EXIF data and provides methods to manipulate and retrieve information from it. It is used in conjunction with JPEG encoding and decoding functions to preserve image metadata.

Remarks

Note that ExifMetadata does not have a copy constructor. This is because ExifData is a C struct and never heard of memory management and RAII. When calling this function, use move semantics, e.g.

std::vector<unsigned char> encoded_image = celantur::jpeg_encode(image, 95, std::move(metadata));

The destruction of the metadata is taken care in the jpeg_encode.

Constructor & Destructor Documentation

ExifMetadata() [1/3]

celantur::ExifMetadata::ExifMetadata

(

ExifData *

data

)

Constructor that takes ownership of an ExifData pointer.

Parameters

data	Pointer to ExifData from libexif. The ExifMetadata instance takes ownership and will free it upon destruction.

~ExifMetadata()

celantur::ExifMetadata::~ExifMetadata

(

)

ExifMetadata() [2/3]

celantur::ExifMetadata::ExifMetadata ( const ExifMetadata &  )

delete

ExifMetadata() [3/3]

celantur::ExifMetadata::ExifMetadata ( ExifMetadata &&  other )

noexcept

Move constructor.

Member Function Documentation

get_orientation()

int celantur::ExifMetadata::get_orientation

(

)

const

Retrieve the orientation value from the EXIF metadata. This function extracts the orientation tag from the EXIF data, which indicates how the image should be rotated for correct display.

Returns

An integer representing the orientation value. Common values are 1 (normal), 3 (180 degrees), 6 (90 degrees clockwise), and 8 (90 degrees counter-clockwise).

operator=() [1/2]

ExifMetadata& celantur::ExifMetadata::operator= ( const ExifMetadata &  )

delete

operator=() [2/2]

ExifMetadata & celantur::ExifMetadata::operator= ( ExifMetadata &&  other )

noexcept

Move assignment operator.

print_exif_content()

void celantur::ExifMetadata::print_exif_content	(	ExifContent *	content,
		std::ostream &	oss
	)		const

Print the contents of an ExifContent structure to the provided output stream. This function iterates through all entries in the ExifContent and prints their details.

Parameters

content	Pointer to the ExifContent structure to be printed.
oss	Output stream where the EXIF content will be printed.

print_exif_entry()

void celantur::ExifMetadata::print_exif_entry	(	ExifEntry *	entry,
		std::ostream &	oss
	)		const

Print the EXIF metadata to the provided output stream. This function outputs the EXIF metadata in a human-readable format, useful for debugging and.

Member Data Documentation

metadata

ExifData* celantur::ExifMetadata::metadata {nullptr}

Pointer to the underlying ExifData structure. This pointer is managed by the ExifMetadata instance and should not be accessed directly.

Returns

Pointer to ExifData.