Rotates JPEG images based on EXIF orientation.

• What does it do
• Installation
• Usage
  • CLI
  • Node module
    • Sample usage
    • Error handling
  • Options
• Changelog
• License
• Credits

This tool applies the right orientation to a JPEG image, based on its EXIF tag. More precisely, it:

• Rotates the pixels
• Rotates the thumbnail, if there is one
• Writes 1 in the Orientation EXIF tag (this is the default orientation)
• Updates the PixelXDimension and PixelYDimension EXIF values
• Does not alter the other EXIF tags

It may be useful, if:

• You need to compress your image with a tool that strips EXIF data without rotating the pixels (like the great ImageOptim)
• You need to upload the image, but the destination application does not support EXIF orientation (like WordPress)
• You just want to get rid of the orientation tag, while leaving the other tags intact

More information about EXIF:

• EXIF Orientation Handling Is a Ghetto
• Standard EXIF Tags

Install with npm:

$ npm install jpeg-autorotate --global
# --global isn't required if you plan to use the node module

# Rotates a single image
$ jpeg-autorotate /Users/johan/IMG_1234.jpg
# Rotates a set of images
$ jpeg-autorotate /Users/johan/images/IMG_*.jpg

The tool is available as a Node module. It will load the image, apply the rotation, and return the binary data as a Buffer, allowing you to:

• Save it on disk
• Load it in an image processing module (like jimp, lwip, gm...)
• ...

var jo = require('jpeg-autorotate');
var options = {quality: 85};
jo.rotate('/Users/johan/IMG_1234.jpg', options, function(error, buffer, orientation)
{
    if (error)
    {
        console.log('An error occurred when rotating the file: ' + error.message);
        return;
    }
    console.log('Orientation was: ' + orientation);
    // ...
    // Do whatever you need with the buffer
    // ...
});

The error object returned in the callback contains a readable message, but also a code for better error handling. Available codes are the following:

var jo = require('jpeg-autorotate');

jo.errors.read_file; // File could not be opened
jo.errors.read_exif; // EXIF data could not be read
jo.errors.no_orientation; // No orientation tag was found
jo.errors.unknown_orientation; // The orientation tag is unknown
jo.errors.correct_orientation; // The image orientation is already correct
jo.errors.rotate_file; // An error occurred when rotating the image

Sample usage:

var jo = require('jpeg-autorotate');
jo.rotate('/image.jpg', function(error, buffer, orientation)
{
    if (error && error.code === jo.errors.correct_orientation)
    {
        console.log('The orientation of this image is already correct!');
    }
});

The following options are available.

To use options with the CLI:

$ jpeg-autorotate /image.jpg --jobs=100 --quality=85

This project uses semver.

This project is released under the MIT License.

• piexifjs
• jpeg-js
• exif-orientation-examples
• async
• colors
• yargs
• FontAwesome
• Chai
• Mocha