Since its version FastTrack 7.2, Nuxeo natively lets you read/write metadata, using exiftool by default. As always with Nuxeo, the fetaure is configurable, so you can customize the metadata you want to get/set, you have operations to handle the metadata, ...

You can find the documentation on our website, and the source code on GitHub.

So, now that the feature is in Nuxoe, this plug-in will not be maintained, please use Nuxeo native feature instead.

This plug-in allows to use ImageMagick, GraphicsMagic or ExifTool to read any binary metadata, and ExifTool to write metadata

nuxeo-binary-metadata is a plug-in for the nuxeo platform. It allows to read/write metadata stored in blobs (basically, a file on disk), letting nuxeo developers to store these information in the document, for easy search, display and reporting. It uses the ìm4java tool for this purpose, which, itself, encapsulates calls to ImageMagick and, possibly, ExifTool and GraphicsMagick.

Each tool has a home page and documentation explaining the usage of tags.

WARNING Tags are not the same depending on the tool you use.

Requirements:

• For reading metadata, the plug-in lets you pickup the tool you want to use, so make sure this tool is installed on your server. It is either ImageMagick, GraphicsMagic or ExifTool. Actually, you can use the 3 of them if you wish, and switch from one to another when reading metadata (for example, maybe one tool can read a very specific metadata that the others cant')
• For writing metadata, only ExifTool is used, so if you want to write metadata, you must have ExifTool installed on your server.

• Operations
  • Document: Extract Binary Metadata
  • Blob: Extract XMP
  • Blob: Write Metadata
  • Document: Write Blob Metadata
• Build-Install
• Third Party Tools Used
• License
• About Nuxeo

Receives a Document as input and put the requested metadata in fields, and optionally save the document.

• xpath is the xpath to the binary, in the document. It is set by default to file:content, which means the default main binary.
• When the save box is checked then the document will be automatically saved. Not checking this box is interesting when the next operations, for example, will also update some fields (we some time want to avoid saving the document in the database, triggering events, etc.)
• tool lets you select which tool must be used: ImageMagick (default), GraphicsMagick or ExifTool.
• The properties parameter is a list a key=value elements (separated by a line), where key is the XPATH of a field and value is the exact name (case sensitive) of a picture metadata field, as returned by too used.
  • When used with ImageMagick/GraphicsMagick tool, the plug-in calls identify -verbose command. Sub-properties use a colon as separator (image statistics:Overall:standard deviation for example).
  • With ExifTool, the plug-in calls the -all tag.
  • WARNING Tags are not the same depending on the tool you use

Here is an example of properties used with ImageMagick:

dc:format=Format
a_schema_prefix:a_field=Units
another_schema_prefix:some_field=Number pixels
my_channel:red=Channel depth:red
my_channel:red=Channel depth:green
my_channel:red=Channel depth:blue
... etc ...

In this example, the plugin will store in dc:format the value of the Format field, in my_channel:red the value of Channel depth:red, etc.

• Special value
  
• all: If a value is set to "all" (dc:description=all for example), then all the available values are returned as a raw result, formatted by the tool used. This is a good way to check what kind of values you can expect. The whole values could also be stored in a string field and full-text indexed.

Receives a Blob as input and fill a context variable which will be filled with all the XMP metadata (as a XML string)

WARNING: This operation uses ExifTool (no choice in the tool to use).

• Expects one required parameter, varName, which will be filled with the raw XML of the XMP metadata stored in the blob. If the blob has no XMP metadata, the variable is set to the empty string, "".

An example of Automation Chain using this operation would be:

Fetch > Context Document(s)
Files > Get Document File
Files > Extract XMP
  varName: theXMP
. . .

The theXMP context variable be used. For example, an MVEL expression could check it is is empty (no XMP in the file) or not: @{theXMP.isEMpty()}

Receives a Blob as input and set the its metadata using a properties list.

WARNING: This operation uses ExifTool (no choice in the tool to use).

• workOnACopy: If ture, the blob is first duplicated. The metadata is written in this copy, and it is this copy that is returned by the operation. If set to false, then the blob received as input is modified and returned.
• properties is a list a key=value elements (separated by a line), where key is the name of the tag and value is, well, the value so set.
  • Notice that setting an empty value removes the tag (keywords= for example)
  • An example of use could be:

Keywords=nuxeo, awesome, amazing
Title=How cool is nuxeo
Subject=cf. the title

Receives a Document as input and sets the metadata of its embedded blob

• xpath if the xpath of the field holding the binary. Default value is file:content
• When the save box is checked then the document will be automatically saved. Not checking this box is interesting when the next operations, for example, will also update some fields (we some time want to avoid saving the document in the database, triggering events, etc.)
• • properties is a list a key=value elements (separated by a line), where key is the name of the tag and value is, well, the value so set.
  • Notice that setting an empty value removes the tag (keywords= for example)
• See the example for Blob: Write Metadata

Assuming maven (min. 3.2.1) is installed on your computer:

# Clone the GitHub repository
cd /path/to/where/you/want/to/clone/this/repository
git clone https://github.com/ThibArg/nuxeo-binary-metadata
# Compile
cd nuxeo-binary-metadata
mvn clean install

• The plug-in is in nuxeo-binary-metadata/nuxeo-binary-metadata-plugin/target/, its name is nuxeo-binary-metadata-plugin-{version}.jar.
• The Marketplace Package is in nuxeo-binary-metadata/nuxeo-binary-metadata-mp/target, its name is nuxeo-binary-metadata-mp-{version}.zip.

If you want to import the source code in Eclipse, then after the first build, cd nuxeo-binary-metadata-plugin and mvn eclipse:eclipse. Then, in Eclipse, choose "File" > "Import...", select "Existing Projects into Workspace" navigate to the nuxeo-binary-metadata-plugins folder and select this folder.

• im4java
im4java (http://im4java.sourceforge.net) is used as the main tool to extract the metadata from the images. It is a very good and powerful tool which saves a lot of development time by having already everything requested.
  im4java is licensed under the LGPL

• Other tools depend up on you: ImageMagick, GraphicsMagic and ExifTool.

(C) Copyright 2014 Nuxeo SA (http://nuxeo.com/) and others.

All rights reserved. This program and the accompanying materials are made available under the terms of the GNU Lesser General Public License (LGPL) version 2.1 which accompanies this distribution, and is available at http://www.gnu.org/licenses/lgpl-2.1.html

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

Contributors: Thibaud Arguillere (https://github.com/ThibArg)

Nuxeo provides a modular, extensible Java-based open source software platform for enterprise content management and packaged applications for Document Management, Digital Asset Management and Case Management. Designed by developers for developers, the Nuxeo platform offers a modern architecture, a powerful plug-in model and extensive packaging capabilities for building content applications.