GExiv2.Metadata

Subclasses:None

Methods

Inherited:GObject.Object (37) Structs:GObject.ObjectClass (5)

class	get_tag_description (tag)
class	get_tag_label (tag)
class	get_tag_type (tag)
class	is_exif_tag (tag)
class	is_iptc_tag (tag)
class	is_xmp_tag (tag)
class	new ()
class	register_xmp_namespace (name, prefix)
class	unregister_all_xmp_namespaces ()
class	unregister_xmp_namespace (name)
	clear ()
	clear_comment ()
	clear_exif ()
	clear_iptc ()
	clear_tag (tag)
	clear_xmp ()
	delete_gps_info ()
	erase_exif_thumbnail ()
	free ()
	from_app1_segment (data)
	from_stream (stream)
	generate_xmp_packet (xmp_format_flags, padding)
	get_comment ()
	get_exif_tag_rational (tag)
	get_exif_tags ()
	get_exif_thumbnail ()
	get_exposure_time ()
	get_fnumber ()
	get_focal_length ()
	get_gps_altitude ()
	get_gps_info ()
	get_gps_latitude ()
	get_gps_longitude ()
	get_iptc_tags ()
	get_iso_speed ()
	get_metadata_pixel_height ()
	get_metadata_pixel_width ()
	get_mime_type ()
	get_orientation ()
	get_pixel_height ()
	get_pixel_width ()
	get_preview_image (props)
	get_preview_properties ()
	get_supports_exif ()
	get_supports_iptc ()
	get_supports_xmp ()
	get_tag_interpreted_string (tag)
	get_tag_long (tag)
	get_tag_multiple (tag)
	get_tag_raw (tag)
	get_tag_string (tag)
	get_xmp_packet ()
	get_xmp_tags ()
	has_exif ()
	has_iptc ()
	has_tag (tag)
	has_xmp ()
	open_buf (data)
	open_path (path)
	save_external (path)
	save_file (path)
	set_comment (comment)
	set_exif_tag_rational (tag, nom, den)
	set_exif_thumbnail_from_buffer (buffer)
	set_exif_thumbnail_from_file (path)
	set_gps_info (longitude, latitude, altitude)
	set_metadata_pixel_height (height)
	set_metadata_pixel_width (width)
	set_orientation (orientation)
	set_tag_long (tag, value)
	set_tag_multiple (tag, values)
	set_tag_string (tag, value)
	set_xmp_tag_struct (tag, type)
	update_gps_info (longitude, latitude, altitude)

Virtual Methods

Inherited:GObject.Object (7)

Properties

None

Signals

Inherited:GObject.Object (1)

Fields

Inherited:GObject.Object (1)

Name	Type	Access	Description
parent_instance	GObject.Object	r

Class Details

class GExiv2.Metadata(**kwargs)

Bases:GObject.Object Abstract:No Structure:GExiv2.MetadataClass

An object holding all the Exiv2 metadata. Previews, if present, are also available.

As gexiv2 is only a wrapper around Exiv2, it’s better to read its documentation to understand the full scope of what it offers: ` <http://www.exiv2.org/>`__

In particular, rather than providing a getter/setter method pair for every metadata value available for images (of which there are thousands), Exiv2 uses a dotted addressing scheme. For example, to access a photo’s EXIF Orientation field, the caller passes to Exiv2 “Exif.Photo.Orientation”. These tags (in Exiv2 parlance) are key to using Exiv2 (and therefore gexiv2) to its fullest.

A full reference for all supported Exiv2 tags can be found at

` <http://www.exiv2.org/metadata.html>`__

classmethod get_tag_description(tag)

Parameters:tag (str) – An Exiv2 tag Returns:The tag’s description Return type:str or None

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

classmethod get_tag_label(tag)

Parameters:tag (str) – An Exiv2 tag Returns:The tag’s label Return type:str or None

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

classmethod get_tag_type(tag)

Parameters:tag (str) – An Exiv2 tag Returns:The tag’s type name. Return type:str or None

The names of the various Exiv2 tag types can be found at Exiv2::TypeId,

` <http://exiv2.org/doc/namespaceExiv2.html#5153319711f35fe81cbc13f4b852450c>`__ The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

classmethod is_exif_tag(tag)

Parameters:tag (str) – An Exiv2 tag Returns:True if the Exiv2 tag is for the EXIF domain. Return type:bool

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

classmethod is_iptc_tag(tag)

Parameters:tag (str) – An Exiv2 tag Returns:True if the Exiv2 tag is for the IPTC domain. Return type:bool

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

classmethod is_xmp_tag(tag)

Parameters:tag (str) – An Exiv2 tag Returns:True if the Exiv2 tag is for the XMP domain. Return type:bool

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

classmethod new()

Returns:A fully constructed GExiv2.Metadata ready to be used Return type:GExiv2.Metadata

classmethod register_xmp_namespace(name, prefix)

Parameters:

• name (str) – XMP URI name (should end in /)
• prefix (str) – XMP namespace prefix

Returns:

Boolean success value

Return type:

bool

classmethod unregister_all_xmp_namespaces()

classmethod unregister_xmp_namespace(name)

Parameters:name (str) – XMP URI name (should end in /) Returns:Boolean success value Return type:bool

clear()

Removes all tags for all domains (EXIF, IPTC, and XMP).

clear_comment()

This is a composite clear method that will clear a number of fields. See GExiv2.Metadata.get_comment for more information.

clear_exif()

Clears all EXIF metadata from the loaded image.

clear_iptc()

Clears all IPTC metadata from the loaded image.

clear_tag(tag)

Parameters:tag (str) – Exiv2 tag Returns:True if the tag was present. Return type:bool

Removes the Exiv2 tag from the metadata object.

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

clear_xmp()

Clears all XMP metadata from the loaded image.

delete_gps_info()

Removes all GPS metadata from the loaded image

erase_exif_thumbnail()

Removes the EXIF thumbnail from the loaded image.

free()

Destroys the GExiv2.Metadata object and frees all associated memory.

Deprecated since version 0.10.3: Use GObject.Object.unref() instead.

from_app1_segment(data)

Parameters:data (bytes) – A buffer containing the data to be read Raises:GLib.Error Returns:Boolean success indicator. Return type:bool

Load only an EXIF buffer, typically stored in a JPEG’s APP1 segment.

from_stream(stream)

Parameters:stream (Gio.InputStream) – A Gio.InputStream to get meta-data from Raises:GLib.Error Returns:Boolean success indicator Return type:bool

Read meta-data from a GIO stream

generate_xmp_packet(xmp_format_flags, padding)

Parameters:

• xmp_format_flags (GExiv2.XmpFormatFlags) – One of GExiv2.XmpFormatFlags
• padding (int) – The padding (FIXME: Add documentation)

Returns:

Encode the XMP packet and return as a None-terminated string.

Return type:

str or None

Encode the XMP packet as a None-terminated string.

get_comment()

Returns:The photo’s comment field. Return type:str or None

A composite accessor that uses the first available metadata field from a list of well-known locations to find the photo’s comment (or description).

MWG guidelines refer to these as Description: a textual description of a resource’s content.

These fields are:

• Exif.Image.ImageDescription (MWG Guidelines)
• Exif.Photo.UserComment
• Exif.Image.XPComment
• Iptc.Application2.Caption (MWG Guidelines)
• Xmp.dc.description (MWG Guidelines)
• Xmp.acdsee.notes (Commonly requested, read only)

Note that in the EXIF specification Exif.Image.ImageDescription is described as “the title of the image”. Also, it does not support two-byte character codes for encoding. However, it’s still used here for legacy reasons.

For fine-grained control, it’s recommended to use Exiv2 tags directly rather than this method, which is more useful for quick or casual use.

get_exif_tag_rational(tag)

Parameters:tag (str) – The tag you want the rational value for Returns:Boolean success value

nom:The numerator den:The denominator

Return type:(bool, nom: int, den: int)

Fetch EXIF tag represented by a fraction. nom will contain the numerator, den the denominator of the fraction on successful return.

get_exif_tags()

Returns:A list of the available EXIF tags in the loaded image Return type:[str]

Query self for a list of available EXIF tags

get_exif_thumbnail()

Returns:Boolean success value

buffer:Where to store the thumbnail data

Return type:(bool, buffer: bytes)

Get the thumbnail stored in the EXIF data of self

get_exposure_time()

Returns:Boolean success value

nom:The numerator den:The denominator

Return type:(bool, nom: int, den: int)

Returns the exposure time in seconds (shutter speed, not date-time of exposure) as a rational. See ` <https://en.wikipedia.org/wiki/Shutter_speed>`__ for more information.

get_fnumber()

Returns:The exposure Fnumber as a float, or -1.0 if tag is not present or invalid. Return type:float

See ` <https://en.wikipedia.org/wiki/F-number>`__ for more information. If Exif.Photo.FNumber does not exist, it will fall back to calculating the FNumber from Exif.Photo.ApertureValue (if available);

get_focal_length()

Returns:The focal length as a float, or -1.0 if tag is not present or invalid. Return type:float

See ` <https://en.wikipedia.org/wiki/Flange_focal_distance>`__ for more information.

get_gps_altitude()

Returns:Boolean success value

altitude:Variable to store the altitude value

Return type:(bool, altitude: float)

Convenience function to query the altitude stored in the GPS tags of the image

get_gps_info()

Returns:Boolean success value.

longitude:Storage for longitude value latitude:Storage for latitude value altitude:Storage for altitude value

Return type:(bool, longitude: float, latitude: float, altitude: float)

Convenience function to query all available GPS information at once.

get_gps_latitude()

Returns:Boolean success value

latitude:Variable to store the latitude value

Return type:(bool, latitude: float)

Query the latitude stored in the GPS tags of self

get_gps_longitude()

Returns:Boolean success value

longitude:Variable to store the longitude value

Return type:(bool, longitude: float)

Query the longitude stored in the GPS tags of self

get_iptc_tags()

Returns:A list of the available IPTC tags Return type:[str]

Query self for a list of available IPTC tags

get_iso_speed()

Returns:The ISO speed rating as a int, or 0 if tag is not present or invalid. Return type:int

See ` <https://en.wikipedia.org/wiki/Iso_speed>`__ for more information.

get_metadata_pixel_height()

Returns:Height of images in pixels as stored in the metadata Return type:int

Composite accessor to query the pixel with stored in the metadata. This might differ from the height of image that is available through GExiv2.Metadata.get_pixel_height()

get_metadata_pixel_width()

Returns:Width of images in pixels as stored in the metadata Return type:int

Composite accessor to query the pixel with stored in the metadata. This might differ from the width of image that is available through GExiv2.Metadata.get_pixel_width()

get_mime_type()

Returns:The MIME type of the loaded image, None if not loaded or unknown. Return type:str

Query mime type of currently loaded image.

get_orientation()

Returns:A GExiv2.Orientation value representing the EXIF orientation value. Return type:GExiv2.Orientation

The EXIF Orientation field

get_pixel_height()

Returns:Pixel height of current image Return type:int

Get the actual unoriented display height in pixels of the loaded image. This may be different than the height reported by various metadata tags, i.e. “Exif.Photo.PixelYDimension”.

get_pixel_width()

Returns:Pixel width of current image Return type:int

Get the actual unoriented display width in pixels of the loaded image. May be different than the width reported by various metadata tags, i.e. “Exif.Photo.PixelXDimension”.

get_preview_image(props)

Parameters:props (GExiv2.PreviewProperties) – A GExiv2.PreviewProperties instance Returns:A GExiv2.PreviewImage instance for the particular GExiv2.PreviewProperties. Return type:GExiv2.PreviewImage

get_preview_properties()

Returns:An array of GExiv2.PreviewProperties instances, one for each preview present in the loaded image. Return type:[GExiv2.PreviewProperties] or None

An image may have stored one or more previews, often of different qualities, sometimes of different image formats than the containing image. This call returns the properties of all previews Exiv2 finds within the loaded image. Use GExiv2.Metadata.get_preview_image to load a particular preview into memory.

get_supports_exif()

Returns:True if the loaded image type supports writing EXIF metadata. Return type:bool

Query self whether it supports writing EXIF metadata.

get_supports_iptc()

Returns:True if the loaded image type supports writing IPTC metadata. Return type:bool

Query self whether it supports writing IPTC metadata.

get_supports_xmp()

Returns:True if the loaded image type supports writing XMP metadata. Return type:bool

Query self whether it supports writing XMP metadata.

get_tag_interpreted_string(tag)

Parameters:tag (str) – Exiv2 tag name Returns:The tag’s interpreted value as a string Return type:str or None

An interpreted string is one fit for user display. It may display units or use formatting appropriate to the type of data the tag holds.

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

get_tag_long(tag)

Parameters:tag (str) – Exiv2 tag name Returns:The tag’s value as a int Return type:int

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

get_tag_multiple(tag)

Parameters:tag (str) – Exiv2 tag name Returns:The multiple string values of the tag Return type:[str] or None

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

get_tag_raw(tag)

Parameters:tag (str) – Exiv2 tag name Returns:The tag’s raw value as a byte array Return type:GLib.Bytes or None

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

get_tag_string(tag)

Parameters:tag (str) – Exiv2 tag name Returns:The tag’s value as a string Return type:str or None

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

get_xmp_packet()

Returns:The currently-encoded XMP packet (see GExiv2.Metadata.generate_xmp_packet). Return type:str or None

get_xmp_tags()

Returns:A list of the available XMP tags Return type:[str]

has_exif()

Returns:True if EXIF metadata is present in the loaded image Return type:bool

has_iptc()

Returns:True if IPTC metadata is present in the loaded image Return type:bool

has_tag(tag)

Parameters:tag (str) – Exiv2 tag Returns:True if the tag is present. Return type:bool

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

has_xmp()

Returns:True if XMP metadata is present in the loaded image Return type:bool

open_buf(data)

Parameters:data (bytes) – A buffer containing the data to be read Raises:GLib.Error Returns:Boolean success indicator Return type:bool

The buffer must be an image format supported by Exiv2.

open_path(path)

Parameters:path (str) – Path to the file you want to open Raises:GLib.Error Returns:Boolean success indicator Return type:bool

The file must be an image format supported by Exiv2.

save_external(path)

Parameters:path (str) – Path to the file you want to save to. Raises:GLib.Error Returns:Boolean success indicator. Return type:bool

Saves the metadata to the specified using an XMP sidecar file.

New in version 0.10.6.

save_file(path)

Parameters:path (str) – Path to the file you want to save to. Raises:GLib.Error Returns:Boolean success indicator. Return type:bool

Saves the metadata to the specified file by reading the file into memory,copying this object’s metadata into the image, then writing the image back out.

set_comment(comment)

Parameters:comment (str) – Comment string to set. Must not be None

This is a composite setter that will set a number of fields to the supplied value. See GExiv2.Metadata.get_comment for more information.

set_exif_tag_rational(tag, nom, den)

Parameters:

• tag (str) – The Exiv2 tag
• nom (int) – Rational numerator
• den (int) – Rational denominator

Returns:

Boolean success value

Return type:

bool

Set EXIF tag represented by a fraction, with nom being the numerator, den the denominator of the fraction.

set_exif_thumbnail_from_buffer(buffer)

Parameters:buffer (bytes) – A buffer containing thumbnail data

set_exif_thumbnail_from_file(path)

Parameters:path (str) – Path of image file Raises:GLib.Error Returns:Boolean success value Return type:bool

Sets or replaces the EXIF thumbnail with the image in the file

set_gps_info(longitude, latitude, altitude)

Parameters:

• longitude (float) – Longitude value to set or replace current value
• latitude (float) – Latitude value to set or replace current value
• altitude (float) – Altitude value to set or replace current value

Returns:

Boolean success value.

Return type:

bool

Convenience function to create a new set of simple GPS data. Warning: Will remove any other GPS information that is currently set. See GExiv2.Metadata.update_gps_info() for just modifying the GPS data.

set_metadata_pixel_height(height)

Parameters:height (int) – The width of the image as it should be put into the metadata.

Update the image’s metadata with height

set_metadata_pixel_width(width)

Parameters:width (int) – The width of the image as it should be put into the metadata.

Composite setter to update the image’s metadata with width

set_orientation(orientation)

Parameters:orientation (GExiv2.Orientation) – The new GExiv2.Orientation for the image.

The orientation must be valid and cannot be GExiv2.Orientation.UNSPECIFIED.

set_tag_long(tag, value)

Parameters:

• tag (str) – Exiv2 tag name
• value (int) – The value to set or replace the existing value

Returns:

True on success

Return type:

bool

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

set_tag_multiple(tag, values)

Parameters:

• tag (str) – Exiv2 tag name
• values ([str]) – An array of values to set or replace the existing value(s)

Returns:

Boolean success value

Return type:

bool

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

set_tag_string(tag, value)

Parameters:

• tag (str) – Exiv2 tag name
• value (str) – The value to set or replace the existing value

Returns:

True on success

Return type:

bool

The Exiv2 Tag Reference can be found at ` <http://exiv2.org/metadata.html>`__

set_xmp_tag_struct(tag, type)

Parameters:

• tag (str) –
• type (GExiv2.StructureType) –

Return type:

bool

update_gps_info(longitude, latitude, altitude)

Parameters:

• longitude (float) – Longitude value to set or replace current value
• latitude (float) – Latitude value to set or replace current value
• altitude (float) – Altitude value to set or replace current value

Returns:

Boolean success value.

Return type:

bool

Convenience function to update longitute, latitude and altitude at once.

New in version 0.12.1.