PictureMetaData Class Reference

Reads Exif metadata from a picture using libexiv2. More...

Inheritance diagram for PictureMetaData:

Collaboration diagram for PictureMetaData:

Public Member Functions
	PictureMetaData (const QString &filePath)
	Constructor. Reads metadata from image. More...
	~PictureMetaData () override=default
bool	IsValid () override
QStringList	GetAllTags () override
	Returns all metadata tags. More...
int	GetOrientation (bool *exists=nullptr) override
	Read Exif orientation. More...
QDateTime	GetOriginalDateTime (bool *exists=nullptr) override
	Read Exif timestamp of image capture. More...
QString	GetComment (bool *exists=nullptr) override
	Read Exif comments from metadata. More...
Public Member Functions inherited from ImageMetaData
virtual	~ImageMetaData ()=default

Protected Member Functions
std::string	GetTag (const QString &key, bool *exists=nullptr)
	Read a single Exif metadata tag. More...
Protected Member Functions inherited from ImageMetaData
	ImageMetaData (QString filePath)

Static Protected Member Functions
static QString	DecodeComment (std::string rawValue)
	Decodes charset of UserComment. More...

Protected Attributes
Exiv2::Image::UniquePtr	m_image
Exiv2::ExifData	m_exifData
Protected Attributes inherited from ImageMetaData
QString	m_filePath
	Image filepath. More...

Additional Inherited Members
Public Types inherited from ImageMetaData
using	TagMap = QMultiMap< QString, QStringList >
Static Public Member Functions inherited from ImageMetaData
static ImageMetaData *	FromPicture (const QString &filePath)
	Factory to retrieve metadata from pictures. More...
static ImageMetaData *	FromVideo (const QString &filePath)
	Factory to retrieve metadata from videos. More...
static QString	ToString (const QString &name, const QString &label, const QString &value)
	Encodes metadata into a string as <tag name><tag label><tag value> More...
static QStringList	FromString (const QString &str)
	Decodes metadata name, label, value from a string. More...
static TagMap	ToMap (const QStringList &tags)
	Creates a map of metadata tags as. More...
Static Public Attributes inherited from ImageMetaData
static const QString	kSeparator = "|-|"
	Unique separator to delimit fields within a string. More...

Detailed Description

Reads Exif metadata from a picture using libexiv2.

Definition at line 258 of file imagemetadata.cpp.

Constructor & Destructor Documentation

PictureMetaData()

PictureMetaData::PictureMetaData ( const QString &  filePath )

explicit

Constructor. Reads metadata from image.

Parameters

filePath

Absolute image path

Definition at line 285 of file imagemetadata.cpp.

~PictureMetaData()

PictureMetaData::~PictureMetaData ( )

overridedefault

Member Function Documentation

IsValid()

bool PictureMetaData::IsValid ( )

inlineoverridevirtual

Implements ImageMetaData.

Definition at line 264 of file imagemetadata.cpp.

Referenced by GetAllTags(), GetTag(), and PictureMetaData().

GetAllTags()

QStringList PictureMetaData::GetAllTags ( )

overridevirtual

Returns all metadata tags.

Ignores "Exif.Image.PrintImageMatching" and lengthy tag values, which are probably proprietary/binary

Returns

List of encoded strings

See also

ImageMetaData::FromString()

Implements ImageMetaData.

Definition at line 315 of file imagemetadata.cpp.

GetOrientation()

int PictureMetaData::GetOrientation ( bool *  exists = nullptr )

overridevirtual

Read Exif orientation.

Parameters

[out]

exists

(Optional) True if orientation is defined by metadata

Returns

Exif orientation code

Implements ImageMetaData.

Definition at line 416 of file imagemetadata.cpp.

GetOriginalDateTime()

QDateTime PictureMetaData::GetOriginalDateTime ( bool *  exists = nullptr )

overridevirtual

Read Exif timestamp of image capture.

Parameters

[out]

exists

(Optional) True if date exists in metadata

Returns

Timestamp (possibly invalid) in camera timezone

Implements ImageMetaData.

Definition at line 428 of file imagemetadata.cpp.

GetComment()

QString PictureMetaData::GetComment ( bool *  exists = nullptr )

overridevirtual

Read Exif comments from metadata.

Returns UserComment, if not empty. Otherwise returns ImageDescription

Parameters

[out]

exists

(Optional) True if either comment is found in metadata

Returns

Comment as a string

Implements ImageMetaData.

Definition at line 444 of file imagemetadata.cpp.

DecodeComment()

QString PictureMetaData::DecodeComment ( std::string  rawValue )

staticprotected

Decodes charset of UserComment.

Parameters

rawValue

Metadata value with optional "[charset=...]" prefix

Returns

Decoded comment

Definition at line 467 of file imagemetadata.cpp.

Referenced by GetAllTags(), and GetComment().

GetTag()

std::string PictureMetaData::GetTag ( const QString &  key, bool *  exists = nullptr  )

protected

Read a single Exif metadata tag.

Parameters

[in]	key	Exif tag key, as per http://www.exiv2.org/tags.html
[out]	exists	(Optional) True if key is found in metadata

Returns

Encoded tag

See also

ImageMetaData::FromString()

Definition at line 388 of file imagemetadata.cpp.

Referenced by GetComment(), GetOrientation(), and GetOriginalDateTime().

Member Data Documentation

m_image

Exiv2::Image::UniquePtr PictureMetaData::m_image

protected

Definition at line 276 of file imagemetadata.cpp.

Referenced by IsValid(), and PictureMetaData().

m_exifData

Exiv2::ExifData PictureMetaData::m_exifData

protected

Definition at line 277 of file imagemetadata.cpp.

Referenced by GetAllTags(), GetTag(), and PictureMetaData().

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

• imagemetadata.cpp