Native Image Format Metadata Queries

This topic provides an overview of the metadata query language queries for reading and writing metadata supported by GIF, PNG, TIFF and JPEG images.It includes metadata that is specific to each image format, as well as metadata that is supported by multiple formats.

This topic contains the following sections.

Prerequisites

To understand this topic, you should be familiar with the Windows Imaging Component (WIC) metadata system as described in the WIC Metadata Overview. You should also be familiar with the query language used to read and write metadata, as described in Metadata Query Language Overview.

Photo Metadata Policy Expression

In addition to supporting the metadata query language, WIC also accepts canonical property names from the Windows Property System. WIC supports a subset of the Windows property namespace that is relevant to image formats, as described in Photo Metadata Policies. A Windows property that is used as a WIC metadata query is referred to as a photo metadata policy expression.

For example, the photo metadata policy expression for the EXIF orientation flag is:

In general, policy expressions are recommended over native metadata queries for common image metadata items that are covered by the Windows property namespace. The metadata query language is best suited for cases where low-level access to specific image metadata items is needed, or for custom or advanced metadata items that are not supported by the Windows property system. For more information, see Photo Metadata Policy Expressions.

File Format Specific Metadata

The following sections contain tables that list the available metadata queries for each image file type. Each table has the following columns:

  • Path - The query path used to retrieve the metadata item.
  • Name - The name of the metadata item.
  • Type - The type of the metadata item retrieved from the query path. Metadata retrieved by WIC is returned in the form of PROPVARIANT, which reports the data type using the VARTYPE enumeration.on.

The query paths are used by the WIC metadata API to access the embedded metadata of an image. The following example code demonstrates using an IWICMetadataQueryReader to query for a JPEG's IFD metadata block.

// Not shown: image decoding 
IWICMetadataQueryReader *pQueryReader = NULL;
IWICMetadataQueryReader *pIFDReader = NULL;

// Get the query reader.
if (SUCCEEDED(hr))
{
    hr = pFrameDecode->GetMetadataQueryReader(&pQueryReader);
}

if (SUCCEEDED(hr))
{
    // Get the nested IFD reader.
    hr = pQueryReader->GetMetadataByName(L"/app1/ifd", &value);
    if (value.vt == VT_UNKNOWN)
    {
        hr = value.punkVal->QueryInterface(IID_IWICMetadataQueryReader, (void **)&pIFDReader);
    }
    PropVariantClear(&value); // Clear value for new query.
}

GIF Metadata

The Graphics Interchange Format (GIF) image format supports both global and frame level metadata. The following two sections provide the metadata query paths available for GIF's global and frame level metadata.

Note

For a full list of GIF metadata along with more detailed information, see the GIF standard on the W3C website.

 

Global Metadata

The following table provides the available metadata query paths that can be used to access global GIF metadata.

Path Name Type
/commentext or /[*]commentext where * = 0 to N Comment Extension VT_UNKNOWN - A query reader/writer
/commentext/TextEntry VT_LPSTR
/logscrdesc Logical Screen Description VT_UNKNOWN - A query reader/writer
/logscrdesc/Signature VT_UI1 | VT_VECTOR
/logscrdesc/Height VT_UI2
/logscrdesc/GlobalColorTableFlag VT_UI2
/logscrdesc/ColorResolution VT_BOOL
/logscrdesc/SortFlag VT_UI1
/logscrdesc/GlobalColorTableSize BOOL
/logscrdesc/BackgroundColorIndex VT_UI1
/logscrdesc/PixelAspectRatio VT_UI1
/appext or /[*]appext where * = 0 to N Application Extension VT_UNKNOWN - A query reader/writer
/appext/Application VT_UI1 | VT_VECTOR
/appext/Data VT_UI1 | VT_VECTOR

 

Frame Metadata

The following table provides the available metadata query paths that can be used to access frame level GIF metadata.

Path Name Type
/grctlext Graphic Control Extension VT_UNKNOWN - query reader/writer
/grctlext/Disposal VT_UI1
/grctlext/UserInputFlag VT_BOOL
/grctlext/TransparencyFlag VT_BOOL
/grctlext/Delay VT_UI2
/grctlext/TransparentColorIndex VT_UI1
/imgdesc Image Descriptor VT_UNKNOWN - query reader/writer
/imgdesc/Left VT_UI2
/imgdesc/Top VT_UI2
/imgdesc/Width VT_UI2
/imgdesc/Height VT_UI2
/imgdesc/LocalColorTableFlag VT_BOOL
/imgdesc/InterlaceFlag VT_BOOL
/imgdesc/SortFlag VT_BOOL
/imgdesc/LocalColorTableSize VT_UI1

 

PNG Metadata

The Portable Network Graphics (PNG) image format supports frame level metadata.

Note

For a full list of PNG metadata along with more detailed information, see the PNG standard on the W3C website.

 

Frame Metadata

The following table provides the available metadata query paths that can be used to access frame level PNG metadata.

Path Name Type
/tEXt or /[*]tEXt where * = 0 to N Text Chunk VT_UNKNOWN - tEXt query reader/writer
/tEXt/{str=*} where * = identifying keyword for text VT_LPSTR
/gAMA Gama Chunk VT_UNKNOWN - gAMA query reader/writer
/gAMA/ImageGamma VT_UI4
/iTXt or /[*]iTXt where * = 0 to N IText Chunk VT_UNKNOWN - iTXt query reader/writer
/iTXt/Keyword VT_LPSTR
/iTXt/CompressionFlag VT_UI1
/iTXt/LanguageTag LPSTR
/iTXt/TranslatedKeyword LPWSTR
/iTXt/TextEntry LPWSTR
/cHRM HRM Chunk VT_UNKNOWN - cHRM query reader/writer
/cHRM/WhitePointX VT_UI4
/cHRM/WhitePointY VT_UI4
/cHRM/RedX VT_UI4
/cHRM/RedY VT_UI4
/cHRM/GreenX VT_UI4
/cHRM/GreenY VT_UI4
/cHRM/BlueX VT_UI4
/cHRM/BlueY VT_UI4
/sRGB sRGB Chuck VT_UNKNOWN - sRGB query reader/writer
/sRGB/RenderingIntent VT_UI1
/tIME Time Chunk VT_UNKNOWN - tIME query reader/writer
/tIME/Year VT_UI2
/tIME/Month VT_UI1
/tIME/Day VT_UI1
/tIME/Hour VT_UI1
/tIME/Minute VT_UI1
/tIME/Second VT_UI1
/bKGD Background Chunk VT_UNKNOWN - bKGB query reader/writer
/bKGD/BackgroundColor VT_UI1, VT_UI2 or VT_UI2 | VT_VECTOR
/hIST hIST Chunk VT_UNKNOWN - hIST query reader/writer
/hIST/Frequencies VT_VECTOR | VT_UI2
/iCCP iCCP Chunk VT_UNKNOWN - iCCP query reader/writer
/iCCP/ProfileName VT_LPSTR
/iCCP/ProfileData VT_VECTOR | VT_UI1

 

TIFF Metadata

The Tagged Image File Format (TIFF) image format supports frame level metadata.

Note

For a full list of TIFF metadata along with more detailed information, see the TIFF standard.

 

Frame Metadata

The following table provides the available metadata query paths that can be used to access frame level TIFF metadata.

Path Name Type
/ifd 0 IFD VT_UNKNOWN - A query reader/writer
/ifd/{ushort=*} where * = 0 to 65535 IFD Entry by ID Variable
/ifd/thumb or /ifd/{ushort=330} Thumbnail IFD VT_UNKNOWN - A query reader/writer
/ifd/xmp or /ifd/{ushort=700} XMP VT_UNKNOWN - A query reader/writer
/ifd/exif or /ifd/{ushort=34665} EXIF VT_UNKNOWN - A query reader/writer
/ifd/gps or /ifd/{ushort=34853} GPS VT_UNKNOWN - A query reader/writer
/ifd/exif/interop or /ifd/exif/{ushort=40965} Interop VT_UNKNOWN - A query reader/writer
/ifd/iptc or /ifd/{ushort=33723} IPTC VT_UNKNOWN - A query reader/writer
/ifd/iptc/{str=*} where * = IPTC keyword IPTC Entry Variable
/ifd/irb/8bimiptc/iptc IPTC VT_UNKNOWN - A query reader/writer
/ifd/irb/8bimiptc/iptc/{str=*} IPTC Entry Variable

 

JPEG Metadata

The JPEG image format supports frame level metadata.

Note

For full list of JPEG metadata along with more detailed information, see the EXIF JPEG standard.

 

Frame Metadata

The following table provides the available metadata query paths that can be used to access frame level JPEG metadata.

Path Name Type
/app0 App0 VT_UNKNOWN - App0 Query Reader/Writer
/app0/{ushort=0} Version VT_UI2
/app0/{ushort=1} Units VT_UI1
/app0/{ushort=2} DpiX VT_UI2
/app0/{ushort=3} DpiY VT_UI2
/app0/{ushort=4} Xthumbnail VT_UI1
/app0/{ushort=5} Ythumbnail VT_UI1
/app0/{ushort=6} ThumbnailData VT_BLOB
/app1 App1 VT_UNKNOWN - App1 Query Reader/Writer
/app1/ifd/ or /app1/{ushort=0} 0 IFD VT_UNKNOWN - IFD Query Reader/Writer
/app1/ifd/exif or /app1/ifd/{ushort=34665} EXIF IFD VT_UNKNOWN – EXIF Query Reader/Writer
/app1/thumb/ or /app1/{ushort=1} Thumbnail IFD VT_UNKNOWN - SubIFD Query Reader/Writer
/app13 App13 VT_UNKNOWN - App13 Query Reader/Writer
/app13/irb or /app13/{ushort=0} IRB VT_UNKNOWN - IRB Query Reader/Writer
/app13/irb/{ulonglong=*} where * = IRB Identifier (see IRB spec) IRB Entry VT_UNKNOWN - Unknown Query Reader/Writer
/app13/irb/{ulonglong=*}/{} IRB Entry Contents VT_BLOB
/app13/irb/8bimiptc or /app13/irb/{ulonglong=61857348781060} 8BIMIPTC VT_UNKNOWN - 8BIMIPTC Query Reader/Writer
/app13/irb/8bimiptc/iptc IPTC VT_UNKNOWN - IPTC Query Reader/Writer
/app13/irb/8bimiptc/iptc/{str=*} IPTC Entry Variable
/app13/irb/8bimResInfo or /app13/irb/{ulonglong=61857348781037} 8BIM Resolution Info VT_UNKNOWN - Query Reader/Writer
/app13/irb/8bimResInfo/PString VT_LPSTR
/app13/irb/8bimResInfo/HResolution VT_UI4
/app13/irb/8bimResInfo/VResolution VT_UI4
/app13/irb/8bimResInfo/WidthUnit VT_UI2
/app13/irb/8bimResInfo/HeightUnit VT_UI2
/app13/irb/8bimResInfo/HResolutionUnit VT_UI2
/app13/irb/8bimResInfo/VResolutionUnit VT_UI2
/com JPEG Comment VT_UNKNOWN - Comment Query Reader/Writer
/com/TextEntry LPSTR
/luminance Luminance VT_UNKNOWN - Luminance Query Reader/Writer
/luminance/TableEntry VT_UI1 | VT_VECTOR
/chrominance Chrominance VT_UNKNOWN - Chrominance Query Reader/Writer
/chrominance/TableEntry VT_UI1 | VT_VECTOR
/xmp XMP VT_UNKNOWN - XMP Query Reader/Writer

 

File Format Independent Metadata

The following sections contain information concerning metadata formats that are supported by multiple image formats. Each table has the following columns:

  • Relative Path - The query path used to retrieve the metadata item, relative to the metadata block.
  • Name - The name of the metadata item.
  • Type - The type of the metadata item retrieved from the query path. Metadata retrieved by WIC is returned in the form of PROPVARIANT, which reports the data type using the VARTYPE enumeration.

Note

The tables here only provide the relative path to access a metadata item within the particular metadata format. To get the fully qualified metadata query, append this relative path to the metadata block query for the particular metadata format.

 

For example, to access the Orientation flag in a JPEG file, use the following expression:

  • /app1/ifd/{ushort=274}

In a TIFF file, use the following expression:

  • /ifd/{ushort=274}

In this example, note that different image formats may store a particular metadata block differently, and so the fully qualified metadata query to access a particular metadata item may be image format specific. See each format’s table to find the appropriate metadata query to access a particular metadata block.

IFD Metadata

An IFD, or Image File Directory, is a data structure defined in the TIFF standard that can contain image metadata. It identifies each metadata item using a tag of type ushort. JPEG, TIFF, and JPEG-XR support IFD metadata. Third party formats, like some camera raw formats, may also support IFD metadata.

The table here provides relative metadata query paths to access some commonly used IFD metadata items. The IFD data structure allows for third party extensibility and this table is not an exhaustive list. See the TIFF standard for more information.

Note

Although JPEG and other formats support the IFD data structure, they may not use all of the metadata items that it defines. Refer to each format’s standard for more information.

 

Note

Certain metadata items in the table here require additional interpretation or information to properly use, refer to the TIFF standard. For example, the PhotometricInterpretation metadata item returns a PROPVARIANT of type VT_UI2. However, according to the TIFF standard it is interpreted as an enumeration. See the TIFF standard for more information.

 

Relative Path Name Type
/{ushort=256} ImageWidth VT_UI2 or VT_UI4
/{ushort=257} ImageLength VT_UI2 or VT_UI4
/{ushort=258} BitsPerSample VT_UI2
/{ushort=259} Compression VT_UI2
/{ushort=262} PhotometricInterpretation VT_UI2
/{ushort=274} Orientation VT_UI2
/{ushort=277} SamplesPerPixel VT_UI2
/{ushort=284} PlanarConfiguration VT_UI2
/{ushort=530} YCbCrSubSampling VT_VECTOR | VT_UI2
/{ushort=531} YCbCrPositioning VT_UI2
/{ushort=282} XResolution VT_UI8
/{ushort=283} YResolution VT_UI8
/{ushort=296} ResolutionUnit VT_UI2
/{ushort=306} DateTime VT_LPSTR
/{ushort=270} ImageDescription VT_LPSTR
/{ushort=271} Make VT_LPSTR
/{ushort=272} Model VT_LPSTR
/{ushort=305} Software VT_LPSTR
/{ushort=315} Artist VT_LPSTR
/{ushort=33432} Copyright VT_LPSTR
/{ushort=338} ExtraSamples VT_UI2
/{ushort=254} NewSubfileType VT_UI4
/{ushort=278} RowsPerStrip VT_UI2 or VT_UI4
/{ushort=279} StripByteCounts VT_VECTOR | VT_UI2 or VT_VECTOR | VT_UI4
/{ushort=273} StripOffsets VT_VECTOR | VT_UI2 or VT_VECTOR | VT_UI4

 

EXIF Metadata

EXIF metadata is defined as part of the EXIF JPEG specification. EXIF metadata is based on the IFD data structure as defined in the TIFF standard, and provides additional attributes such as information about the devices and photographic attributes used to create the image. It identifies each metadata item using a tag of type ushort. JPEG, TIFF, and JPEG-XR support EXIF metadata. Third party formats, such as some camera raw formats, may also support EXIF metadata.

The following table provides relative metadata query paths to access some commonly used EXIF metadata items. The EXIF data structure allows for third party extensibility and this table is not an exhaustive list; refer to the EXIF standard for more information.

Note

Many EXIF metadata items are defined in the EXIF standard as type "RATIONAL" or "SRATIONAL". A "RATIONAL" consists of a numerator and denominator, both of which are 32 bit unsigned integers. The numerator is contained in the high 32 bits, and the denominator in the low 32 bits. In WIC, these are returned as PROPVARIANT with a type of VT_UI8 or VT_I8, respectively; the actual value is stored as ULARGE_INTEGER or LARGE_INTEGER, respectively. To access the numerator and denominator, read the HighPart and LowPart members of the ULARGE_INTEGER or LARGE_INTEGER value.

 

Note

Certain metadata items in the below table require additional interpretation or information to properly use. For example, the ColorSpace metadata item returns a PROPVARIANT of type VT_UI2. However, according to the EXIF standard it is interpreted as an enumeration. See the EXIF standard for more information.

 

Relative Path Name Type
/{ushort=36864} ExifVersion VT_BLOB
/{ushort=40960} FlashpixVersion VT_BLOB
/{ushort=40961} ColorSpace VT_UI2
/{ushort=40962} PixelXDimension VT_UI2 or VT_UI4
/{ushort=40963} PixelYDimension VT_UI2 or VT_UI4
/{ushort=37500} MakerNote VT_BLOB
/{ushort=37510} UserComment VT_LPWSTR
/{ushort=36867} DateTimeOriginal VT_LPSTR
/{ushort=36868} DateTimeDigitized VT_LPSTR
/{ushort=42016} ImageUniqueID VT_LPSTR
/{ushort=42032} CameraOwnerName VT_LPSTR
/{ushort=42033} BodySerialNumber VT_LPSTR
/{ushort=42034} LensSpecification VT_VECTOR | VT_UI8
/{ushort=42035} LensMake VT_LPSTR
/{ushort=42036} LensModel VT_LPSTR
/{ushort=42037} LensSerialNumber VT_LPSTR
/{ushort=33434} ExposureTime VT_UI8
/{ushort=33437} FNumber VT_UI8
/{ushort=34850} ExposureProgram VT_UI2
/{ushort=34852} SpectralSensitivity VT_LPSTR
/{ushort=34855} PhotographicSensitivity VT_VECTOR | VT_UI2
/{ushort=34856} OECF VT_BLOB
/{ushort=34864} SensitivityType VT_UI2
/{ushort=34865} StandardOutputSensitivity VT_UI4
/{ushort=34866} RecommendedExposureIndex VT_UI4
/{ushort=34867} ISOSpeed VT_UI4
/{ushort=34868} ISOSpeedLatitudeyyy VT_UI4
/{ushort=34869} ISOSpeedLatitudezzz VT_UI4
/{ushort=37377} ShutterSpeedValue VT_I8
/{ushort=37378} ApertureValue VT_UI8
/{ushort=37379} BrightnessValue VT_I8
/{ushort=37380} ExposureBiasValue VT_I8
/{ushort=37381} MaxApertureValue VT_UI8
/{ushort=37382} SubjectDistance VT_UI8
/{ushort=37383} MeteringMode VT_UI2
/{ushort=37384} LightSource VT_UI2
/{ushort=37385} Flash VT_UI2
/{ushort=37386} FocalLength VT_UI8
/{ushort=37396} SubjectArea VT_VECTOR | VT_UI2
/{ushort=41483} FlashEnergy VT_UI8
/{ushort=41484} SpatialFrequencyResponse VT_BLOB
/{ushort=41486} FocalPlaneXResolution VT_UI8
/{ushort=41487} FocalPlaneYResolution VT_UI8
/{ushort=41488} FocalPlaneResolutionUnit VT_UI2
/{ushort=41492} SubjectLocation VT_VECTOR | VT_UI2
/{ushort=41493} ExposureIndex VT_UI8
/{ushort=41495} SensingMethod VT_UI2
/{ushort=41728} FileSource VT_BLOB
/{ushort=41729} SceneType VT_BLOB
/{ushort=41730} CFAPattern VT_BLOB
/{ushort=41985} CustomRendered VT_UI2
/{ushort=41986} ExposureMode VT_UI2
/{ushort=41987} WhiteBalance VT_UI2
/{ushort=41988} DigitalZoomRatio VT_UI8
/{ushort=41989} FocalLengthIn35mmFilm VT_UI2
/{ushort=41990} SceneCaptureType VT_UI2
/{ushort=41991} GainControl VT_UI8
/{ushort=41992} Contrast VT_UI2
/{ushort=41993} Saturation VT_UI2
/{ushort=41994} Sharpness VT_UI2
/{ushort=41995} DeviceSettingDescription VT_BLOB
/{ushort=41996} SubjectDistanceRange VT_UI2

 

GPS Metadata

GPS metadata contains geolocation information and is defined as part of the EXIF JPEG specification. It identifies each metadata item using a tag of type ushort. JPEG, TIFF, and JPEG-XR support GPS metadata; third party formats, like some camera raw formats, may also support GPS metadata.

The following table provides relative metadata query paths to access some commonly used GPS metadata items. This table is not an exhaustive list; refer to the EXIF standard for more information.

Note

Many GPS metadata items are defined in the EXIF standard as type "RATIONAL". A "RATIONAL" consists of a numerator and denominator, both of which are 32 bit unsigned integers. The numerator is contained in the high 32 bits, and the denominator in the low 32 bits. In WIC, these are returned as PROPVARIANT with a type of VT_UI8. The actual value is stored as ULARGE_INTEGER. To access the numerator and denominator, read the HighPart and LowPart members of the ULARGE_INTEGER value.

 

Note

Certain metadata items in the table here require additional interpretation or information to properly use. For example, the GPSLatitudeRef metadata item returns a PROPVARIANT of type VT_LPSTR. According to the EXIF standard this string is either "N" or "S", representing North or South latitude. See the EXIF standard for more information.

 

Relative Path Name Type
{ushort=0} GPSVersionID VT_VECTOR | VT_UI1
{ushort=1} GPSLatitudeRef VT_LPSTR
{ushort=2} GPSLatitude VT_VECTOR | VT_UI8
{ushort=3} GPSLongitudeRef VT_LPSTR
{ushort=4} GPSLongitude {ushort=4} GPSLongitude VT_VECTOR | VT_UI8
{ushort=5} GPSAltitudeRef VT_UI1
{ushort=6} GPSAltitude VT_UI8
{ushort=7} GPSTimeStamp VT_VECTOR | VT_UI8
{ushort=8} GPSSatellites VT_LPSTR
{ushort=9} GPSStatus VT_LPSTR
{ushort=10} GPSMeasureMode VT_LPSTR
{ushort=11} GPSDOP VT_UI8
{ushort=12} GPSSpeedRef VT_LPSTR
{ushort=13} GPSSpeed VT_UI8
{ushort=14} GPSTrackRef VT_LPSTR
{ushort=15} GPSTrack VT_UI8

 

XMP Metadata

XMP is an XML-based, extensible metadata standard. Metadata items can be hierarchical and contain complex data structures. JPEG, TIFF, and JPEG-XR support XMP metadata. Third party formats, like some camera raw formats, may also support XMP metadata.

The XMP standard can be obtained from: https://www.adobe.com/devnet/xmp.html.

XMP and allows third party entities to publish their own schemas, or namespaces, which allow them to define new metadata items without having to modify the XMP standard. An XMP schema is uniquely identified by a URL, but WIC provides a set of friendly identifiers for well-known schemas.

XMP metadata items are identified by a string name as well as a schema identifier. As a best practice, every XMP metadata query should specify both the schema and name. If the schema identifier is missing, then JPEG will attempt to match the metadata name across all of the namespaces present within the XMP metadata packet.

For example, to obtain the Rating property as defined by the XMP schema in a JPEG image, use the following query:

  • /xmp/{wstr=https://ns.adobe.com/xap/1.0/}:Rating

The first part, "/xmp", retrieves the XMP metadata reader/writer for the image. "https://ns.adobe.com/xap/1.0/" is the URL of the XMP schema, as defined in the XMP standard. The URL is enclosed in a data expression to allow the use of characters such as a forward slash (/). Finally, "Rating" is the actual metadata item name as defined by the XMP schema and it is separated from the schema identifier by a colon (:).

In this example, WIC provides a friendly identifier for the XMP schema which can be used in place of the full URL. So, the previous query can be rewritten as:

  • /xmp/xmp:Rating

WIC provides friendly schema prefixes for the following commonly used schemas:

Schema Prefix Schema URL Link to Standard
rdf https://www.w3.org/1999/02/22-rdf-syntax-ns\ https://www.w3.org/TR/REC-rdf-syntax/
dc https://purl.org/dc/elements/1.1/ https://www.adobe.com/devnet/xmp.html
xmp https://ns.adobe.com/xap/1.0/ https://www.adobe.com/devnet/xmp.html
xmpidq https://ns.adobe.com/xmp/Identifier/qual/1.0/ https://www.adobe.com/devnet/xmp.html
xmpRights https://ns.adobe.com/xap/1.0/rights/ https://www.adobe.com/devnet/xmp.html
xmpMM https://ns.adobe.com/xap/1.0/mm/ https://www.adobe.com/devnet/xmp.html
xmpBJ https://ns.adobe.com/xap/1.0/bj/ https://www.adobe.com/devnet/xmp.html
xmpTPg https://ns.adobe.com/xap/1.0/t/pg/ https://www.adobe.com/devnet/xmp.html
pdf https://ns.adobe.com/pdf/1.3/ https://www.adobe.com/devnet/xmp.html
photoshop https://ns.adobe.com/photoshop/1.0/ https://www.adobe.com/devnet/xmp.html
tiff https://ns.adobe.com/tiff/1.0/ https://www.adobe.com/devnet/xmp.html
exif https://ns.adobe.com/exif/1.0/ https://www.adobe.com/devnet/xmp.html
stDim https://ns.adobe.com/xap/1.0/sType/Dimensions\ https://www.adobe.com/devnet/xmp.html
xapGImg https://ns.adobe.com/xap/1.0/g/img/ https://www.adobe.com/devnet/xmp.html
stEvt https://ns.adobe.com/xap/1.0/sType/ResourceEvent\ https://www.adobe.com/devnet/xmp.html
stRef https://ns.adobe.com/xap/1.0/sType/ResourceRef\ https://www.adobe.com/devnet/xmp.html
stVer https://ns.adobe.com/xap/1.0/sType/Version\ https://www.adobe.com/devnet/xmp.html
stJob https://ns.adobe.com/xap/1.0/sType/Job\ https://www.adobe.com/devnet/xmp.html
aux https://ns.adobe.com/exif/1.0/aux/ https://www.adobe.com/devnet/xmp.html
crs https://ns.adobe.com/camera-raw-settings/1.0/ https://www.adobe.com/devnet/xmp.html
xmpDM https://ns.adobe.com/xmp/1.0/DynamicMedia/ https://www.adobe.com/devnet/xmp.html
Iptc4xmpCore https://iptc.org/std/Iptc4xmpCore/1.0/xmlns/ https://www.iptc.org/cms/site/index.html?channel=CH0099
MicrosoftPhoto https://ns.microsoft.com/photo/1.0/ People Tagging Overview
MP https://ns.microsoft.com/photo/1.2/ People Tagging Overview
MPRI https://ns.microsoft.com/photo/1.2/t/RegionInfo\ People Tagging Overview
MPReg https://ns.microsoft.com/photo/1.2/t/Region\ People Tagging Overview

 

If there is no friendly schema prefix for a particular schema, for example if an image contains XMP metadata using a custom third party schema, the metadata query should use the full schema URL.

Conceptual

Windows Imaging Component Overview

WIC Metadata Overview

Metadata Query Language Overview

Metadata Extensibility Overview

How-to: Re-encode a JPEG Image with Metadata