Manage metadata of your digital assets
Adobe Experience Manager Assets keeps metadata for every asset. It allows easier categorization and organization of assets and it helps people who are looking for a specific asset. With the ability to extract metadata from files uploaded to Experience Manager Assets, metadata management integrates with the creative workflow. With the ability to keep and manage metadata with your assets, you can automatically organize and process assets based on their metadata.
Why we need metadata
Metadata means data about data. In this regard, data refers to your digital asset, say an image. Metadata is critical for efficient asset management.
Metadata is the collection of all the data available for an asset but that is not necessarily contained in that image. Some examples of metadata are:
- Name of the asset.
- Time and date of last modification.
- Size of the asset as it was stored in the repository.
- Name of the folder it is contained in.
- Related assets or applied tags.
The above are the basic metadata properties that Experience Manager can manage for assets, which allows users to see all assets. For example, ordering assets by last modification date is useful when trying to discover recently added assets.
You can add more high-level data to digital assets, for example:
- Type of asset (is it an image, a video, an audio clip, or a document?).
- Owner of the asset.
- Title of the asset.
- Description of the asset.
- Tags assigned to an asset.
More metadata helps you further categorize assets and is helpful as the amount of digital information grows. It is possible to manage a few hundred files based on just the filenames. However, this approach is not scalable. It falls short when the number of people involved and the number of assets managed increase.
With the addition of metadata, the value of a digital asset grows, because the asset becomes,
- More accessible - systems and users can find it easily.
- Easier to manage - you can find assets with the same set of properties easier and apply changes to them.
- Complete - asset carries more information and context with more metadata.
For these reasons, Assets provides you with the right means of creating, managing, and exchanging metadata for your digital assets.
Types of metadata
The two basic types of metadata are technical metadata and descriptive metadata.
Technical metadata is useful for software applications that are dealing with digital assets and should not be maintained manually. Experience Manager Assets and other software automatically determine technical metadata and the metadata may change when the asset is modified. The available technical metadata of an asset depends largely on the file type of the asset. Some examples of technical metadata are:
- Size of a file.
- Dimensions (height and width) of an image.
- Bit rate of an audio or video file.
- Resolution (level of detail) of an image.
Descriptive metadata is metadata concerned with the application domain, for example, the business that an asset is coming from. Descriptive metadata cannot be determined automatically. It is created manually or semi-automatically. For example, a GPS-enabled camera can automatically track the latitude and longitude and add geotag the image.
The cost of manually creating descriptive metadata information is high. So, standards are established to ease the exchange of metadata across software systems and organizations. Experience Manager Assets supports all relevant standards for metadata management.
There are various ways to embed metadata in files. A selection of encoding standards are supported:
- XMP: used by Assets to store the extracted metadata within the repository.
- ID3: for audio and video files.
- Exif: for image files.
- Other/Legacy: from Microsoft Word, PowerPoint, Excel, and so on.
Extensible Metadata Platform (XMP) is an open standard that is used by Experience Manager Assets for all metadata management. The standard offers universal metadata encoding that can be embedded into all file formats. Adobe and other companies support XMP standard as it provides a rich content model. Users of XMP standard and of Experience Manager Assets have a powerful platform to build upon. For more information, see XMP .
Data stored in these ID3 tags is displayed when you play back a digital audio file on either your computer or a portable MP3 player.
ID3 tags are designed for the MP3 file format. Additional information on formats:
- ID3 tags work in MP3 and mp3PRO files.
- WAV has no tags.
- WMA has proprietary tags that do not allow open-source implementation.
- Ogg Vorbis uses Xiph Comments embedded in the Ogg container.
- AAC uses a proprietary tagging format.
Exchangeable image file format (Exif) is the most popular metadata format used in digital photography. It provides a way of embedding a fixed vocabulary of metadata properties in many file formats, such as JPEG, TIFF, RIFF, and WAV. Exif stores metadata as pairs of a metadata name and a metadata value. These metadata name-value-pairs are also called tags, not to be confused with the tagging in Experience Manager. Modern digital cameras create Exif metadata and modern graphics software support it. Exif format is the lowest common denominator for metadata management especially for images.
A major limitation of Exif is that a few popular image file formats such as BMP, GIF, or PNG do not support it.
Metadata fields defined by Exif are typically technical in nature and are of limited use for descriptive metadata management. For this reason, Experience Manager Assets offers mapping of Exif properties into common metadata schemata and into XMP.
Other metadata that can be embedded from files include Microsoft Word, PowerPoint, Excel, and so on.
Manage metadata of your digital assets
Enterprise Manager Assets lets you edit the metadata of multiple assets simultaneously so you can quickly propagate common metadata changes to assets in bulk. Use the Properties page to change metadata properties to a common value or add or modify tags. To customize the metadata Properties page, including adding, modifying, deleting metadata properties, use the Schema editor.
The bulk editing methods work for assets available in a folder or a collection. For the assets that are available across folders or match a common criteria, it is possible to bulk update the metadata after searching .
- Navigate to the location of the assets that you want to edit.
- Select the assets for which you want to edit common properties.
- From the toolbar, tap/click Properties to open the Properties page for the selected assets.When you select multiple assets, the lowest common parent form is selected for the assets. In other words, the Properties page only displays metadata fields that are common across the Properties pages of all the individual assets.
- Modify the metadata properties for selected assets under the various tabs.
- To view the metadata editor for a specific asset, deselect the remaining assets in the list. The metadata editor fields are populated with the metadata for the particular asset.
- In the Properties page, you can remove assets from the asset list by deselecting them. The asset list has all the assets selected by default. The metadata for assets that you remove from the list is not updated.
- At the top of assets list, select the check box near Title to toggle between selecting the assets and clearing the list.
- To select a different metadata schema for the assets, tap/click Settings from the toolbar, and select the desired schema. Save the changes.
- To append the new metadata with the existing metadata in fields that contain multiple values, select Append mode . If you do not select this option, the new metadata replaces the existing metadata in the fields. Tap/click Submit .For single-value fields, the new metadata is not appended to the existing value in the field even if you select Append mode .
Configure limit for bulk metadata update
To prevent DOS-like situation, AEM limits the number of parameters supported in a Sling request. When updating metadata of many assets in one go, you may reach the limit and the metadata does not get updated for more assets. AEM generates the following warning in the logs:
org.apache.sling.engine.impl.parameters.Util Too many name/value pairs, stopped processing after 10000 entries
To change the limit, access Web Console ( Tools > Operations > Web Console ) and change the value of Maximum POST Parameters in Apache Sling Request Parameter Handling OSGi configuration.
Metadata schemas are predefined sets of metadata property definitions that can be used in various applications. Properties are always associated with an asset, meaning that the properties are 'about' the resource.
You can also design your own metadata schemata if none exists that meet your needs. Do not duplicate existing information. Within an organization, separating schemata makes it easier to share metadata. Experience Manager provides you with a default list of the most popular metadata schemata. The list helps you to jumpstart your metadata strategy and quickly pick the metadata properties that you need.
The supported metadata schemata supported are listed below.
- DC - Dublin Core is an important and widely used set of metadata.
- DICOM - Digital Imaging and Communications in Medicine.
- Iptc4xmpCore and iptc4xmpExt - International Press Communications Standard contains many subject-specific metadata.
- RDF - Resource Description Framework - for generic semantic web metadata.
- XMP - Extensible Metadata Platform.
- xmpBJ - Basic Job Ticketing.
The application-specific metadata includes technical and descriptive metadata. If you use such metadata, other applications may not be able to use the metadata. For example, a different image-rendering application may not be able to access Adobe Photoshop metadata. You can create a workflow step that changes an application-specific property to a standard property.
- ACDSee - Metadata managed by the ACDSee program. See www.acdsee.com/ .
- Album - Adobe Photoshop Album.
- CQ - Used by Experience Manager Assets.
- DAM - Used by Experience Manager Assets.
- DEX - Optima SC Description explorer is a collection of tools for metadata and file management for Windows operating systems.
- CRS - Adobe Photoshop Camera Raw .
- LR - Adobe Lightroom.
- MediaPro - iView MediaPro .
- MicrosoftPhoto and MP - Microsoft Photo.
- PDF and PDF/X.
- Photoshop and psAux - Adobe Photoshop.
Digital Rights Management metadata
- CC - Creative Commons.
- PLUS - Picture Licensing Universal System .
- PRL - PRISM Rights Language.
- PUR - PRISM Usage Rights.
- xmpPlus - Integration of PLUS with XMP.
- Exif - Technical information from camera, including GPS position.
- CRS - Camera Raw schema.
- iptc4xmpCore and iptc4xmpExt .
- TIFF - image metadata (not only for TIFF images).
- PDF and PDF/X - Adobe PDF and third-party applications.
- XMP - Extensible Metadata Platform.
- xmpPG - XMP metadata for paged text.
- xmpDM - Dynamic Media.
- xmpMM - Media Management.
Creating metadata-driven workflows help you automate some processes, which improves efficiency. In a metadata-driven workflow, the workflow management system reads the workflow and as a result performs some pre-defined action. For example, some of the ways you could use metadata-driven workflows:
- The workflow can check whether an image has a title or not. If it does not, the system notifies to add a title.
- The workflow can check whether a copyright notice on an asset allows for distribution or not. So, the system sends the asset to one server or the other.
- A workflow can check for assets without pre-defined, mandatory metadata or assets with invalid metadata.