The language specification attribute

Unrestricted text string

An integer

A positive integer (including zero)

A real number

A rational number, expressed either as a decimal fraction or in numerator/denominator form

A fraction, expressed either as a real number, or as the quotient of two integer or real numbers

A string of hexadecimal digits

A date string without the day

A date

A time

A date and time

A time interval

An email address

A phone number

A compass direction

An elevation angle

A latitude value

A longitude value

The root element contains optional default settings, photograph description elements roll (for roll film), sheet (for sheet film), and digital (for photographs taken using a digital camera), and digimage elements describing specific digital images, either direct from a camera or scanner, or derived via editing, composition etc.

Elements contained within a defaults element provide default values for the corresponding elements in which the relevant information has not been specified. A full description of the semantics of this element is rather lengthy, and may be found in the accompanying documentation.

The details of a roll of film (e.g. 35mm, APS, 120). Optional film and processing descriptions are followed by a sequence of optional loading details, optional defaults (to be applied to the following frames), frame descriptions, and optional unloading details. A defaults element must always precede at least one frame element, and load and unload elements, if present, must respectively precede and follow some group of frame elements. The id attribute specifies an identity/name assigned to the roll.

The details of a single sheet of film (e.g. 4x5, 8x10). Optional film, processing and loading descriptions precede the single frame description, which is followed by an optional unloading description. The id attribute specifies an identity/name assigned to the sheet.

The details of a sequence of digital photographs. Each group of frame descriptions may be preceded by a defaults element. The id attribute specifies an identity/name assigned to the digital sequence.

A collection of photograph descriptions that should be grouped together. Particularly useful for sheet film, since each sheet element describes a single photo, but also useful, for example, for a number of roll film descriptions for the same day, event, trip etc. The id attribute allows an identity/name to be assigned to the collection, the cgid attribute provides a collection based id for the group (roll, digital, or sheet), and the optional fstfid and lstfid specify initial and final frame ids for a subset of the frames in the group.

A brief description of the parent element. Provides a description of the scene or location for a specific frame when a child of the scene or location elements, or of an entire collection, roll, or digital photography session, providing information relevant to all of the frames within the grouping, when a child of the collection, roll, or digital elements.

A note for miscellaneous details of the parent element.

A description of the film used.

The manufacturer of the product, e.g. Fuji (when the parent element is film).

The name of a person, business, or product, e.g. Velvia (when the parent element is film).

The ISO film speed, e.g. 50.

The appropriate film developing process. Recommended values are C41 (standard negative film), E6 (standard slide film), K14 (Kodachrome) and B&W (black and white). A custom designation should be used for processes not listed here. As a child of the film element, this indicates the designated process of the film. In the case of cross-processing, a different process may be specified as a child of the developing element.

The type of a film (recommended values for film type are colour positive, colour negative, b&w positive, and b&w negative), camera body (e.g. SLR, TLR, rangefinder), or lens (e.g. zoom, prime).

The film format. Recommended values are APS, 35mm (or 135), 120 or 220 for medium format, and the film size for large format.

The film expiry (expiration in the US) date. The format is YYYY-MM since film expiry dates usually only specify a year and month.

A description of the film processing.

The number of the double/triple check tag affixed to the film by the lab.

A date, represented in the format YYYY[-MM[-DD]].

A time, represented in the format hh[:mm[:ss[.ss*]]]. The optional zone attribute represents the time zone in the format (+|-)hh[:mm].

The lab that developed the film. The optional href attribute represents the laboratory web page.

The address of a person or business.

The phone number of a person or business.

The fax number of a person or business.

The email address of a person or business.

A description of the development stage of processing.

The number of stops push or pull applied during processing.

The development method, e.g. daylight tank, tray etc.

Description of the agitation during development.

The temperature of the developer solution (in degrees Celcius by default).

The amount of time the film spent in the developer, represented in the form %m:%s (minutes:seconds).

The developer solution used.

The dilution of the developer solution.

Film loading details.

Film unloading details.

A container allowing the scope of defaults elements to be restricted to the contained set of frame elements.

The frame element describes a single frame in a roll of film or sequence of digital photos, and also describes the single frame on a piece of sheet film. The id attribute should be an identifying number assigned in chronological sequence (e.g. 01, 02 etc.). If the actual frame number marked on the film differs from the id, it may be recorded using the fn attribute. The fn attribute is also useful in other situations, e.g. when the camera exposes film beginning at the end, so the the id numbers increase in chronological order while the fn values decrease. A frame that is not a child of a digital element should not have a digimage child element.

The physical size of the frame. The value may be specified as actual physical dimensions in the format <width>x<height> (e.g. a value of "24x36" with units "mm" for standard 135 (35mm) film frames, or a value of "56x41.5" with units "mm" for 645 frames on 120 film), in which case the units attribute must be specified, or as standard frame size designations (e.g. "645", "6x6", "6x7", etc. on 120 film, or "4x5", "8x10" etc. large format film), in which case the units attribute must be omitted as an indication that the value does not represent an actual physical measurement.

A description of any damage, such as scratches, to a frame.

The index-image allows the specification of the location of an index image suitable for viewing in an image index, and should therefore be small enough for convenient display in a web browser (for example), but larger than a thumbnail. This facility is useful for constructing indices of frame descriptions, or, within digimage elements, when the actual digital image being described is too large for convenient display in this context.

The name and other details of the photographer. The optional href attribute represents the photographer's web page.

Intellectual Property Rights details

A copyright statement

Details of the copyright owner. The optional href attribute represents the owner's web page.

A description of the scene depicted in the frame

A short descriptive caption for the photograph.

The genre of the scene, e.g. portrait, landscape, sport, travel, macro etc.

Keywords relevant to the description of the scene.

A description of when the photograph was taken.

A description of the event at which the photo was taken.

A description of the location at which the photo was taken. The content model is intended to allow a wide range of locations to be described, but this flexibility also allows incoherent choices, which should be avoided. These descriptions will usually follow one of the patterns: country,region,...,city,... (indicating a location within the borders of some country), ocean,sea,island,... (indicating a location on an island that may be a possession of, but is not considered to be within the borders of, any country), ocean,sea,description (indicating a location removed from any land mass, e.g. on a ship at sea), continent,region,... (indicating a location on a continent that is not within the borders of any country - the continent in question will invariably be Antarctica). With the exception of the description element, child elements with text content should contain only the name of the associated location component, and not a descriptive sentence.

If the location is at sea, at a distance from a continent or island, the ocean may be specified.

The sea, if any, within the relevant ocean (e.g. the Andaman Sea is part of the Indian Ocean).

An island within the specified ocean or sea. This element is intended for islands which may be posessions of, but are not considered an integral part of any country.

The continent of the location. This would usually be omitted, but would be used if the location is not part of any country (e.g. a part of Antarctica).

The country of the location.

A region within the location. The type attribute may be used to specify the type of region (e.g. province, state, etc.). For example, in the US, typical usage would be to use the region element to represent a state, and the subregion or district element to represent a county, while in Italy a region element would represent an official region, and a subregion element would represent a province.

A subdivision of the region. The type attribute may be used to specify the type of subdivision.

A subdivision of the subregion, when necessary. May also be a direct subdivision of the region when the subregion is omitted. The type attribute may be used to specify the type of subdivision.

The city of the location.

A subdivision of the city, such as a suburb, borough, or ward. The type attribute may be used to specify the type of subdivision (e.g. an arrondissement of Paris or a ku (ward) of Tokyo).

A subdivision of the subcity, when necessary (for example, Asakusa is a subdivision of Taito-ku, which is a ward of Tokyo). The type attribute may be used to specify the type of subdivision.

The area is intended for a level of detail below that of city, when a city is specified (e.g. `Central Park'), or below that of district when there is no relevant city (e.g. `Kruger National Park'). The type attribute may be used to specify the type of subdivision.

The subarea is intended for a level of detail below that of area (e.g. 'Conservatory Garden' when the area is 'Central Park', or 'Skukuza Camp' when the area is `Kruger National Park').

A road or city street.

The place is intended for a level of detail below that of area, when appropriate. The type attribute may be used to specify the type of subdivision.

The point is intended for a level of detail below that of place, when necessary.

The (latitude, longitude, altitude) coordinates (e.g. obtained from a GPS device) of the location. The datum attribute specifies the map datum for the coordinate system, which is WGS 84 by default. The relevance attribute specifies whether the coordinates represent an estimate of the specific point at which the photo was taken, or merely indicate the general area (e.g. if the photo was taken at a significant monument, the coordinates might be copies from the wikipedia entry for that monument). The uncertainty attribute provides an estimate of the uncertainty (in units of metres) of the coordinates. When the relevance is set to "area" and an uncertainty estimate is provided, the implication is that the unknown "point" coordinates lie within the uncertainty radius of the provided coordinates.

The location latitude.

The location longitude.

The location altitude (in metres by default). The optional reference attribute specifies whether the specified altitude is Above Mean Sea Level or Above Ground Level.

Details of the measurement of the location coordinates. Note that measurement implies the use of a GPS receiver or other navigation device, while estimation refers to a (usually) less reliable approach, by use of a map or satellite imagery with coordinates, or by comparison with a separate geotagged image of approximately the same scene. The optional association attribute indicates whether the location information was associated with the photo at the time of creation ("immediate"), by use of a GPS device tethered to a DSLR, for example, or at a later stage ("delayed"), by correlating a GPS log with an EXIF time stamp, for example.

Horizontal Dilution of Precision (of a GPS measurement).

Vertical Dilution of Precision (of a GPS measurement).

Positional Dilution of Precision (of a GPS measurement).

Details of the estimation of the coordinates, e.g. by locating relevant features on a map. Typically only one of the measurement or estimation elements will be specified, but if both are present, the implication is that the measured coordinates were modified based on some other method of estimating the position. For example, if GPS data are available, but are inaccurate due to poor reception, the coordinates may be estimated by using a recognised location on a map, but it may still be desired to record the measured location in case the estimate is later found to be poor.

If the coordinates are estimated by comparing the scene with another photo with known coordinates, and which has been assigned a group-id and frame-id, the source-frame element may be used to provide relevant information on the geotagged photo, and the group-id and frame-id attributes should provide its corresponding id tags.

If the approximate coordinates are obtained from some internet resource, the source-ref element may be used to describe the resource, and the href attribute should provide a link to the relevant resource (e.g. a wikipedia entry).

The direction in which the camera was pointed (i.e. from the viewpoint to the scene; coordinates are usually considered to be of the scene viewpoint, and always have this interpretation when direction is specified).

The compass direction of the scene from the viewpoint (e.g. "0" for North, "90" for East, etc.) in the range 0 to 360 (degrees).

The elevation angle of the scene from the viewpoint (e.g. "0" for horizontal, "90" for directly upwards, etc.) in the range -90 to 90 (degrees).

A detailed description of the scene content.

The optional href attribute represents the person's web page.

The optional type and href attributes represent the object type (e.g. building, vehicle) and a URL associated with the object (e.g. for a museum).

A segment of the scene. The label attribute allows identification of segments (e.g. foreground, upper-left, etc.

A description of the camera and associated equipment.

The camera body. While often fixed for a particular roll, it is included here since it forms part of the equipment, and is also not always fixed (e.g. APS mid-roll roll change).

An accessory attached to the body, e.g. motor-drive, multi-function back

A lens.

An accessory attached to the lens, e.g. teleconverter, extension-tube, diopter, filter, lens-hood.

An illumination source, e.g. flash.

A support, e.g. tripod leg set, ball-head, monopod.

A description of an item of equipment. The optional type attribute represents the device type (e.g. filter, ball-head, flash).

The model number/code of a photographic product.

The serial number/code of a photographic product.

The firmware version.

A description of film exposure and camera metering settings.

The lens aperture in f/-stops.

The shutter speed in seconds.

Exposure compensation in EV units.

Flash usage description.

Flash exposure compensation in EV units.

ISO speed setting of the camera (useful if different from the actual film ISO speed, or for a digital camera).

Exposure mode (e.g. program, manual, shutter priority) for an automated camera.

Metering mode (e.g. matrix, centre-weighted, spot).

Information relevant to lens focus.

The lens focal length (useful when the lens doesn't have a fixed focal length), in millimeters by default.

The focal distance (in metres by default).

An evaluation of the merits of the frame. If a score attribute is specified, it represents the aggregate rating for the frame, independent of the score values for child elements; if it is not specified, the aggregate score should be computed as a weighted average of the score attributes of child elements.

An evaluation of the artistic merits of the frame. The element content is a comment on the evaluation, and a numeric rating is provided by the score attribute.

An evaluation of the technical merits (focus, depth of field, etc.) of the frame. The element content is a comment on the evaluation, and a numeric rating is provided by the score attribute.

The details of an individual digital image. The optional href attribute represents the location of the digital image file being described. The group-id attribute is the id of the roll, sheet, or digital element in which the corresponding photographic frame is described, the frame-id attribute is the id of that frame element, and the image-id provides an id number for the specific digital file representing that frame (e.g. two scans of the same film frame would have the same group-id and frame-id, but different image-id.

A container allowing the scope of defaults elements to be restricted to the contained set of digimage elements.

Details of the image properties.

The image width in pixels

The image height in pixels

The bit depth of a sample, commonly 8 or 12 bits per colour band per pixel.

The image format. This may either be described by using the std attribute within an empty element, or omitting the std attribute and describing the format within the element content. When possible, the former approach is preferred.

The ICC profile for the image colour space. The optional href refers to the relevant ICC profile specification file.

The result of a hash function applied to the image file. Not as reliable as the hash value of the image content (i.e. the raw decoded bitmap representation of the image, which is not dependent on the specific image file format), but may be faster to compute in some circumstances, and therefore useful for an initial match test.

The result of a hash function applied to the image content. Useful for ensuring a correct match between the image description and the image data file.

Details of the creation and editing history of the image. More than one editing element is allowed so that multiple stages of editing, using different software, may be described.

Details of the origin of the image; either a film scanner or digital camera, or source image(s) from which it is derived via editing (multiple source images are possible when, for example, a panoramic image is composed of a number of smaller images).

Details of the editing operations applied to the image.

The details of the scanner and scanning process.

The details of the digital camera.

A description of the source image to which editing operations were applied to derive the image described by the image element. The group-id and frame-id attributes should only be used when they differ from the respective values of the image element.

The software used to perform the editing.

The details of the editing operations.

The details of the camera or scanner hardware.

The details of the camera, scanner, or editing software settings.

The name of the company that developed the software.

The version number of the software.

The details of an individual edit. In addition to the text description, further details may be specified by providing the relevant command line when editing was performed via a command shell, or settings for operations applied via a GUI.

The command line used to apply the edit.

The setting element describes software configuration settings during scanning. The name attribute should contain the name of the setting (e.g. multi-pass, ICE), and the element content represents the corresponding value.