Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

Accessing JPEG EXIF rotation data in JavaScript on the client side

People also ask

How do I view EXIF orientation?

1 Answer. Show activity on this post. When you go to File > File Info, select Raw Data. The data will be available under Orientation as a number.

How do I view EXIF data on a JPEG?

Just right-click on the photo in question and select “Properties”. Click on the “Details” tab and scroll down—you'll see all kinds of information about the camera used, and the settings the photo was taken with.

What is EXIF Extractor?

BR's EXIFextracter. BR's EXIFextractor is a simple freeware program that will extract the EXIF meta information from all digital photos (JPEG and TIFF files only) in a folder (optionally including subfolders) and saves the data in a CSV-file (Comma Separated Values).

Does JPEG have EXIF data?

Basically, Exif file format is the same as JPEG file format. Exif inserts some of image/digicam information data and thumbnail image to JPEG in conformity to JPEG specification. Therefore you can view Exif format image files by JPEG compliant Internet browser/Picture viewer/Photo retouch software etc.


If you only want the orientation tag and nothing else and don't like to include another huge javascript library I wrote a little code that extracts the orientation tag as fast as possible (It uses DataView and readAsArrayBuffer which are available in IE10+, but you can write your own data reader for older browsers):

function getOrientation(file, callback) {
    var reader = new FileReader();
    reader.onload = function(e) {

        var view = new DataView(e.target.result);
        if (view.getUint16(0, false) != 0xFFD8)
        {
            return callback(-2);
        }
        var length = view.byteLength, offset = 2;
        while (offset < length) 
        {
            if (view.getUint16(offset+2, false) <= 8) return callback(-1);
            var marker = view.getUint16(offset, false);
            offset += 2;
            if (marker == 0xFFE1) 
            {
                if (view.getUint32(offset += 2, false) != 0x45786966) 
                {
                    return callback(-1);
                }

                var little = view.getUint16(offset += 6, false) == 0x4949;
                offset += view.getUint32(offset + 4, little);
                var tags = view.getUint16(offset, little);
                offset += 2;
                for (var i = 0; i < tags; i++)
                {
                    if (view.getUint16(offset + (i * 12), little) == 0x0112)
                    {
                        return callback(view.getUint16(offset + (i * 12) + 8, little));
                    }
                }
            }
            else if ((marker & 0xFF00) != 0xFF00)
            {
                break;
            }
            else
            { 
                offset += view.getUint16(offset, false);
            }
        }
        return callback(-1);
    };
    reader.readAsArrayBuffer(file);
}

// usage:
var input = document.getElementById('input');
input.onchange = function(e) {
    getOrientation(input.files[0], function(orientation) {
        alert('orientation: ' + orientation);
    });
}
<input id='input' type='file' />

values:

-2: not jpeg
-1: not defined

enter image description here

For those using Typescript, you can use the following code:

export const getOrientation = (file: File, callback: Function) => {
  var reader = new FileReader();

  reader.onload = (event: ProgressEvent) => {

    if (! event.target) {
      return;
    }

    const file = event.target as FileReader;
    const view = new DataView(file.result as ArrayBuffer);

    if (view.getUint16(0, false) != 0xFFD8) {
        return callback(-2);
    }

    const length = view.byteLength
    let offset = 2;

    while (offset < length)
    {
        if (view.getUint16(offset+2, false) <= 8) return callback(-1);
        let marker = view.getUint16(offset, false);
        offset += 2;

        if (marker == 0xFFE1) {
          if (view.getUint32(offset += 2, false) != 0x45786966) {
            return callback(-1);
          }

          let little = view.getUint16(offset += 6, false) == 0x4949;
          offset += view.getUint32(offset + 4, little);
          let tags = view.getUint16(offset, little);
          offset += 2;
          for (let i = 0; i < tags; i++) {
            if (view.getUint16(offset + (i * 12), little) == 0x0112) {
              return callback(view.getUint16(offset + (i * 12) + 8, little));
            }
          }
        } else if ((marker & 0xFF00) != 0xFF00) {
            break;
        }
        else {
            offset += view.getUint16(offset, false);
        }
    }
    return callback(-1);
  };

  reader.readAsArrayBuffer(file);
}

You can use the exif-js library in combination with the HTML5 File API: http://jsfiddle.net/xQnMd/1/.

$("input").change(function() {
    var file = this.files[0];  // file
        fr   = new FileReader; // to read file contents

    fr.onloadend = function() {
        // get EXIF data
        var exif = EXIF.readFromBinaryFile(new BinaryFile(this.result));

        // alert a value
        alert(exif.Make);
    };

    fr.readAsBinaryString(file); // read the file
});

Firefox 26 supports image-orientation: from-image: images are displayed portrait or landscape, depending on EXIF data. (See sethfowler.org/blog/2013/09/13/new-in-firefox-26-css-image-orientation.)

There is also a bug to implement this in Chrome.

Beware that this property is only supported by Firefox and is likely to be deprecated.


https://github.com/blueimp/JavaScript-Load-Image is a modern javascript library that can not only extract the exif orientation flag - it can also correctly mirror/rotate JPEG images on the client side.

I just solved the same problem with this library: JS Client-Side Exif Orientation: Rotate and Mirror JPEG Images