How to Access JPEG EXIF Rotation Data Client-Side in JavaScript?

Accessing JPEG EXIF Rotation Data Client-Side in JavaScript

When dealing with JPEG images, accessing EXIF rotation data can prove invaluable for presenting photos in their proper orientation. To achieve this client-side, JavaScript provides a straightforward solution.

One approach is to utilize JavaScript's FileReader API. By reading the JPEG file as an ArrayBuffer, you can access the EXIF data as a binary stream. Using a DataView object, parse the stream to extract the orientation tag.

Here's a snippet that demonstrates this approach:

<code class="javascript">function getOrientation(file, callback) {
  var reader = new FileReader();
  reader.onload = function(e) {
    var view = new DataView(e.target.result);
    ...
    // Parse EXIF data and extract orientation tag
    ...
    callback(orientation);
  };
  reader.readAsArrayBuffer(file);
}</code>

Alternatively, if you need only the orientation tag, a more efficient approach involves directly extracting the tag without parsing the entire EXIF data. This can be achieved with the following code:

<code class="javascript">function getOrientation(file, callback) {
  ...
  // Read orientation tag directly
  ...
  callback(orientation);
}</code>

By implementing this client-side solution, you can access JPEG EXIF rotation data effortlessly, enabling you to display photos in their intended orientation directly within the browser.

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