Exif orientation

Get orientation (rotation and flipping) info from Exif-ed JPEG or Update orientation code.

Usage

npm install @ginpei/exif-orientation

import * as exif from '@ginpei/exif-orientation';

const orientation = await exif.getOrientation(fileOrBuffer);
console.log(
  `${orientation.rotation} degree,`,
  orientation.flipped ? 'flipped' : 'not flipped',
);

import * as exif from '@ginpei/exif-orientation';

await exif.updateOrientationCode(fileOrBuffer, exif.OrientationCode.deg90Flipped);

Examples

See https://github.com/ginpei/exif-orientation-example.

Read file from <input type="file">

// get file accessor
const elFile = document.querySelector<HTMLInputElement>('#file');
const file = elFile.files[0];

// get orientation
const orientation = await exif.getOrientation(file);

Read file from fs.readFile()

// read file as buffer
const buffer = fs.readFileSync(path);

// get orientation
const orientation = await exif.getOrientation(buffer);

API References

import

import * as exif from '@ginpei/exif-orientation';

This package does not have default.

To import in TypeScript, you need to set moduleResolution option. Find detail in Q&A section below.

function getOrientation(input: File | Buffer | ArrayBuffer): Promise<IOrientationInfo | undefined>

• input: File | Buffer | ArrayBuffer : JPEG file data.

If the input is not JPEG file with Exif containing orientation information, it returns undefined.

function updateOrientationCode (input: File | Buffer | ArrayBuffer, orientation: OrientationCode): Promise<void>

• input: File | Buffer | ArrayBuffer : JPEG file data.
• orientation: OrientationCode : Orientation number.

function readOrientationCode(input: File | Buffer | ArrayBuffer): Promise<OrientationCode>

• input: File | Buffer | ArrayBuffer : JPEG file data.

enum OrientationCode

• OrientationCode.original
• OrientationCode.deg90
• OrientationCode.deg180
• OrientationCode.deg270
• OrientationCode.flipped
• OrientationCode.deg90Flipped
• OrientationCode.deg180Flipped
• OrientationCode.deg270Flipped
• OrientationCode.unknown

function getOrientationInfo(orientation: OrientationCode): IOrientationInfo | undefined

• orientation: OrientationCode

interface IOrientationInfo

interface IOrientationInfo {
  rotation: number;
  flipped: boolean;
}

Q&A

Exif?

Exif is a kind of data format inside JPEG image file. It can contain rotation and flipping information.

If you see an image rotated weirdly, it might be caused by lacking logic for this Exif orientation information.

• Exif - Wikipedia

Following PDF file (Japanese) really helped to implement. Thanks!

• ディジタルスチルカメラ用 - DC-008-2012_J.pdf

Cannot find module '@ginpei/exif-orientation'

src/index.ts:1:23 - error TS2307: Cannot find module '@ginpei/exif-orientation'.

1 import * as exif from '@ginpei/exif-orientation';
                        ~~~~~~~~~~~~~~~~~~~~~~~~~~


Found 1 error.

You have to set moduleResolution in either way:

• In tsconfig.json: "moduleResolution": "node"
• From CLI: --moduleResolution node

See:

• Compiler Options · TypeScript

History

• 2021-10-22: v1.2.0
  • #20 Support images containing APP1 that is not Exif (Marcello Bastéa-Forte @marcello3d)
  • #22 Support images containing Exif without orientation
• 2020-07-13: v1.1.0
  • Add updateOrientationCode() (Tony Brobston @TonyBrobston)
• 2019-01-06: v1.0.0
  • First Release

License

• MIT License

Contact

• by Ginpei
• GitHub: ginpei/exif-orientation
• Twitter: @ginpei_en