exif-js

What is exif-js?

The exif-js npm package is a JavaScript library that allows you to extract EXIF (Exchangeable Image File Format) metadata from image files. This metadata can include information such as the camera model, exposure time, GPS location, and more.

What are exif-js's main functionalities?

Extract EXIF Data

This feature allows you to extract all EXIF metadata from an image file. The code reads an image file and uses the `getData` method to extract the metadata, which is then logged to the console.

const EXIF = require('exif-js');
const fs = require('fs');

fs.readFile('path/to/image.jpg', (err, data) => {
  if (err) throw err;
  EXIF.getData(data, function() {
    const allMetaData = EXIF.getAllTags(this);
    console.log(allMetaData);
  });
});

Get Specific EXIF Tag

This feature allows you to extract a specific EXIF tag from an image file. The code reads an image file and uses the `getTag` method to extract the 'Make' tag, which is then logged to the console.

const EXIF = require('exif-js');
const fs = require('fs');

fs.readFile('path/to/image.jpg', (err, data) => {
  if (err) throw err;
  EXIF.getData(data, function() {
    const make = EXIF.getTag(this, 'Make');
    console.log('Camera Make: ' + make);
  });
});

Get GPS Data

This feature allows you to extract GPS data from an image file. The code reads an image file and uses the `getTag` method to extract the 'GPSLatitude' and 'GPSLongitude' tags, which are then logged to the console.

const EXIF = require('exif-js');
const fs = require('fs');

fs.readFile('path/to/image.jpg', (err, data) => {
  if (err) throw err;
  EXIF.getData(data, function() {
    const gpsData = {
      latitude: EXIF.getTag(this, 'GPSLatitude'),
      longitude: EXIF.getTag(this, 'GPSLongitude')
    };
    console.log('GPS Data: ', gpsData);
  });
});

Other packages similar to exif-js

piexifjs

piexifjs is a JavaScript library for reading and writing EXIF metadata in JPEG images. Unlike exif-js, which focuses on reading EXIF data, piexifjs also allows you to modify and write EXIF data back to the image.

exifr

exifr is a modern JavaScript library for reading EXIF, IPTC, and XMP metadata from image files. It supports a wider range of metadata formats compared to exif-js and is optimized for performance.

jpeg-js

jpeg-js is a pure JavaScript library for decoding and encoding JPEG images. While it does not focus specifically on EXIF metadata, it can be used in conjunction with other libraries to handle image data and metadata.

README

Exif.js

A JavaScript library for reading EXIF meta data from image files.

You can use it on images in the browser, either from an image or a file input element. Both EXIF and IPTC metadata are retrieved. This package can also be used in AMD or CommonJS environments.

Note: The EXIF standard applies only to .jpg and .tiff images. EXIF logic in this package is based on the EXIF standard v2.2 (JEITA CP-3451, included in this repo).

Install

Install exif-js through NPM:

npm install exif-js --save    

Or Bower:

bower install exif-js --save

Then add a script tag in your an HTML in the best position referencing your local file.

<script src="vendors/exif-js/exif-js"></script>

Note: This repo has no .min.js. Do your own minification if you want that.

If you prefer another package manager you will probably manage :D. Or you can clone this GIT repository or download it's ZIP file and extract exif.js to your project.

Usage

The package adds a global EXIF variable (or AMD or CommonJS equivalent).

Start with calling the EXIF.getData function. You pass it an image as a parameter:

• either an image from a <img src="image.jpg">
• OR a user selected image in a <file type="input"> element on your page.

As a second parameter you specify a callback function. In the callback function you should use this to access the image with the aforementioned metadata you can then use as you want. That image now has an extra exifdata property which is a Javascript object with the EXIF metadata. You can access it's properties to get data like the image caption, the date a photo was taken or it's orientation.

You can get all tages with EXIF.getTag. Or get a single tag with EXIF.getTag, where you specify the tag as the second parameter. The tag names to use are listed in EXIF.Tags in exif.js.

Important: Note that you have to wait for the image to be completely loaded, before calling getData or any other function. It will silently fail otherwise. You can implement this wait, by running your exif-extracting logic on the window.onLoad function. Or on an image's own onLoad function. For jQuery users please note that you can NOT (reliably) use jQuery's ready event for this. Because it fires before images are loaded. You could use $(window).load() instead of $(document.ready() (please note that `exif-js has NO dependency on jQuery or any other external library).

JavaScript:

window.onload=getExif;

function getExif() {
    var img1 = document.getElementById("img1");
    EXIF.getData(img1, function() {
        var make = EXIF.getTag(this, "Make");
        var model = EXIF.getTag(this, "Model");
        var makeAndModel = document.getElementById("makeAndModel");
        makeAndModel.innerHTML = `${make} ${model}`;
    });

    var img2 = document.getElementById("img2");
    EXIF.getData(img2, function() {
        var allMetaData = EXIF.getAllTags(this);
        var allMetaDataSpan = document.getElementById("allMetaDataSpan");
        allMetaDataSpan.innerHTML = JSON.stringify(allMetaData, null, "\t");
    });
}

HTML:

<img src="image1.jpg" id="img1" />
<pre>Make and model: <span id="makeAndModel"></span></div>
<br/>
<img src="image2.jpg" id="img2" />
<pre id="allMetaDataSpan"></pre>
<br/>

Note there are also alternate tags, such the EXIF.TiffTags. See the source code for the full definition and use. You can also get back a string with all the EXIF information in the image pretty printed by using EXIF.pretty. Check the included example/index.html.

Please refer to the source code for more advanced usages such as getting image data from a File/Blob object (EXIF.readFromBinaryFile).

Contributions

This is an open source project. Please contribute by forking this repo and issueing a pull request. The project has had notable contributions already, like reading ITPC data. You can also contribute by filing bugs or new features please issue. Or improve the documentation. Please update this README when you do a pull request of proposed changes in base functionality.