神刀安全网

Rotating JPEG images based on their EXIF orientation with node

Rotating JPEG images based on their EXIF orientation with node Rotating JPEG images based on their EXIF orientation with node Rotating JPEG images based on their EXIF orientation with node Rotating JPEG images based on their EXIF orientation with node Rotating JPEG images based on their EXIF orientation with node

Rotating JPEG images based on their EXIF orientation with node

Rotates JPEG images based on EXIF orientation.

What does it do

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

Installation

Install with npm :

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

Usage

CLI

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

Node module

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 (likejimp, lwip ,gm…)

Sample usage

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     // ... });

Error handling

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!');     } });

Options

The following options are available.

Option Context Default value Description
quality CLI, module 100 Quality of the JPEG – Uncompressed by default, so the resulting image may be bigger than the original one
jobs CLI 10 Max number of concurrent processes, when loading several images

To use options with the CLI:

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

Changelog

This project uses semver .

Version Date Notes
1.1.0 2016-04-23 Adds test suite, removes lwip dependency
1.0.3 2016-03-29 Displays help when no path given in CLI
1.0.2 2016-03-21 Adds missing options in CLI help
1.0.1 2016-03-21 Fixes NPM publishing fail ^_^
1.0.0 2016-03-21 Initial version

License

This project is released under theMIT License.

Credits

转载本站任何文章请注明:转载至神刀安全网,谢谢神刀安全网 » Rotating JPEG images based on their EXIF orientation with node

分享到:更多 ()

评论 抢沙发

  • 昵称 (必填)
  • 邮箱 (必填)
  • 网址