exifreader

ExifReader

ExifReader is a JavaScript library that parses image files and extracts the metadata. It can be used either in a browser or from Node. Supports JPEG files with tags encoded using Exif, IPTC, and XMP.

ExifReader supports module formats AMD, CommonJS and globals and can therefore easily be used from Webpack, RequireJS, Browserify, Node etc. Since it is written using ES2015, you can also import the ES2015 module directly from your own ES2015 project.

Installation

Easiest is through npm or Bower:

npm install exifreader --save

bower install exifreader --save

If you want to clone the git repository instead:

git clone [e-mail]:mattiasw/ExifReader.git
cd ExifReader
npm install

After that, the transpiled, concatenated and minified ES5 file will be in the dist folder together with a sourcemap file.

Type definitions

Type definitions for TypeScript are included in the package.

Usage

Importing

ES modules:

import ExifReader from 'exifreader';

CommonJS/Node modules:

const ExifReader = require('exifreader');

AMD modules:

requirejs(['/path/to/exif-reader.js'], function (ExifReader) {
    ...
});

script tag:

<script src="/path/to/exif-reader.js"></script>

Loading tags

const tags = ExifReader.load(fileBuffer);
const imageDate = tags['DateTimeOriginal'].description;
const unprocessedTagValue = tags['DateTimeOriginal'].value;

By default, Exif, IPTC and XMP tags are grouped together. This means that if e.g. Orientation exists in both Exif and XMP, the first value (Exif) will be overwritten by the second (XMP). If you need to separate between these values, pass in an options object with the property expanded set to true:

const tags = ExifReader.load(fileBuffer, {expanded: true});

Notes

Some XMP tags have processed values as descriptions. That means that e.g. an Orientation value of 3 will have Rotate 180 in the description property. If you would like more XMP tags to have a processed description, please file an issue or do a pull request.

Some text tags use TextDecoder to decode their content. If your specific environment does not support it at all or a specific encoding, you will not be able to see the decoded value. One example is when Node.js wasn't compiled with support for the specific encoding.

Client/Browser Support

The library makes use of the DataView API which is supported in Chrome 9+, Firefox 15+, Internet Explorer 10+, Edge, Safari 5.1+, Opera 12.1+. If you want to support a browser that doesn't have DataView support, you should probably use a polyfill like jDataView.

Node.js has had support for DataView since version 0.12 but ExifReader will also try to polyfill it for versions before that (this is not well tested though).

Examples

A full HTML example page is located in the examples/html/ directory. The example uses the FileReader API which is supported by the latest versions of all the major browsers.

Also, there is a Node.js example in the examples/nodejs/ directory.

Tips

• After parsing the tags, consider deleting the MakerNote tag if you know you will load a lot of files and storing the tags. It can be really large for some manufacturers. See the examples folder to see how you can do that.

Testing

Testing is done with Mocha and Chai. Run with:

npm test

Issues

• The descriptions for UserComment, GPSProcessingMethod and GPSAreaInformation are missing for other encodings than ASCII.

License

ExifReader uses the Mozilla Public License 2.0 (MPL-2.0). In short that means you can use this library in your project (open- or closed-source) as long as you mention the use of ExifReader and make any changes to ExifReader code available if you would to distribute your project. But please read the full license text to make sure your specific case is covered.

Changelog

• January 2019:
  • For Node.js, remove dependency of jDataView and explicit dependency of XMLDOM.
  • Add type definitions for TypeScript.
• February, 2018:
  • Change license to Mozilla Public License 2.0 (MPL-2.0).
• December, 2017:
  • Add option to separate different tag groups (Exif, IPTC and XMP).
• February, 2017:
  • Add support for XMP tags.
• December, 2016:
  • Merge IPTC branch.
  • Convert project to JavaScript (ECMAScript 2015) from CoffeeScript, transpiling to ES5 using Babel.
  • Remove need to instatiate the ExifReader object before use.
  • Add UMD support (CommonJS, AMD and global).
  • Publish as npm package.
• September 17, 2014:
  • Lower memory usage by unsetting the file data object after parsing.
  • Add deleteTag method to be able to delete tags that use a lot of memory, e.g. MakerNote.
• September 9, 2013:
  • Make parsing of APP markers more robust. Fixes problems with some pictures.
• July 13, 2013:
  • Throw Error instead of just strings.
• April 23, 2013:
  • Support hybrid JFIF-EXIF image files.
• April 22, 2013:
  • Registered with Bower.
• January 8, 2013:
  • Updated text about browser support.
• January 19, 2012:
  • Added text descriptions for the tags.
• January 1, 2012:
  • First release.