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    exifer

    1.0.0-beta.2 • Public • Published

    exifer

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    A lightweight exif image meta-data decipher
    Exifer is a small module that read JPEG/TIFF meta-data.

    Exif tags/fields are used to encode additional information into images taken by digital still cameras. The exif meta information is organized into different Image File Directories (IFD's) within the image. It contains useful information like image rotation, GPS coordinates, times stamps. ISO, etc.

    Learn more about exif tags

    Features

    • 📦 Lightweight: Small with zero Dependencies
    • 🔍 Extract Exif, GPS, XMP and IPTC
    • 📷 Files: Support both JPEG and TIFF files
    • 📚 Add-ons: Extra tags and parsers available
    • ♻️ Isomorphic: Works in node.js and the browser

    This module exposes three module definitions:

    • ES Module: dist/exifer.mjs
    • UMD: dist/exifer.umd.js
    • CommonJS: dist/exifer.js

    Install

    $ npm install exifer
    

    The script can also be directly included from unpkg.com:

    <script src="https://unpkg.com/exifer"></script>

    Usage

    import exifer from 'exifer'
    import fs from 'fs';
     
    const buffer = fs.readFileSync('photo.jpg');;
    const tags = await exifer(buffer);
    // {
    //   Make: 'Apple',
    //   Model: 'iPhone X',
    //   Orientation: 6,
    //   Software: '12.4',
    //   ModifyDate: '2019:08:25 15:07:02',
    //   ... and so on
    // }

    API

    exifer(input, [opts])

    Returns: object <Promise>

    Takes a JPEG or JIFF image as input and returns an object with extracted meta-data. A Promise is returned that resolves to an hash-map of tag/value pairs.

    Exifer only reads the most essential tags out of the box – which should cover 99% of all use cases. Tags are by default interpreted as ASCII strings.

    To read or parse more tags chekcout opts.tags.

    input

    Type: Buffer|ArrayBuffer|File

    Example running in the browser reading a File (ArrayBuffer):

    import exifer from 'exifer';
     
    /**
     * Assume 'input' is the value coming from an input field:
     * <input type="file" accept="image/*" id="input" >
     */
     
    const input = document.getElementById('#input').files[0];
    const tags = await exifer(input);

    Example running in node.js reading a JPEG Buffer:

    import exifer from 'exifer';
    import fs from 'fs';
     
    const buffer = fs.readFileSync('photo.jpg');;
    const tags = await exifer(buffer);

    opts.tags

    Type: object

    Exifer does not extract more than the most essential tags.

    You can extract additional tags, or overwrite the default tags, if you want to read more tags or write custom parsers. You can do this by passing tag objects to either tags.exif, tags.gps and/or tags.iptc.

    The key for additional IFD image tags is the IFD field code in hexadecimal notation. The value is a tag object with at least a name property.

    Here's an example where two custom gps tag objects passed as tags.gps:

    import exifer from 'exifer';
    import fs from 'fs';
     
    // try to read more GPS tags and parse timestamp
    const gps = {
      0x0001: {name: 'GPSLatitudeRef'},
      0x0007: {name: 'GPSTimeStamp', parse: x => {
        return new Date(Date.UTC(1970, 0, 1, x[0], x[1], x[2]));
      }}
    }
     
    const buffer = fs.readFileSync('photo.jpg');
    const parsed = await exifer(buffer, {tags: { gps }});
    // {
    //    ...
    //    GPSLatitudeRef: 'N',
    //    GPSTimeStamp: 1970-01-01T19:06:58.000Z
    //    ...
    // }
    }
    opts.tags.exif

    Type: object
    default: {}

    Hash-map with additonal exif tags.

    OBS: Find list of exif tags here

    opts.tags.iptc

    Type: object
    default: {}

    Hash-map with additonal IPTC tags.

    OBS: Find list of IPTC tags here

    opts.tags.gps

    Type: object
    default: {}

    Hash-map with additonal GPS tags.

    OBS: Find list of exif tags here

    Add-ons

    If you want to read all tags the following exifer add-on packages have you covered:

    To read and parse all exif and tiff tags using add-ons, you simply import and pass them to the corresponding tags option:

    import exifer from 'exifer';
    import iptc from '@exifer/iptc';
    import exif from '@exifer/exif';
    import fs from 'fs';
     
    const buffer = fs.readFileSync('photo.jpg');
    const parsed = await exifer(buffer, {tags: { exif, iptc }});

    options.skipexif

    Type: boolean
    Default: false

    Skip exif tags.

    options.skipiptc

    Type: boolean
    Default: false

    Skip IPTC tags.

    options.skipxmp

    Type: boolean
    Default: false

    Skip XMP tags.

    Tag

    Type: Object

    Exifer only comes with a few built-in tags. None of the default tag objects have parsers associated with them.

    Example with a rather useless parser:

    {name: 'ModifyDate', raw: false, parse: x => `date is ${x}`}

    tag.name

    Type: String

    Required tag name. This is used as the key in the returned result object from exifer.

    OBS: name is the only required porperty.

    tag.raw

    Type: Boolean
    Default: false

    By default all tags are interpreted as ASCII strings. Set raw to true to get the raw tag value.

    tag.parse

    Type: Function

    Custom parser function. Use this to transform tag values. Input is a ASCII string unless raw is true.

    The returned output is used in the final result object returned by exifer.

    Credit

    Inspired by exif-orientation and ExifReader.

    License

    MIT © Terkel Gjervig

    Install

    npm i exifer

    DownloadsWeekly Downloads

    959

    Version

    1.0.0-beta.2

    License

    MIT

    Unpacked Size

    60.3 kB

    Total Files

    5

    Last publish

    Collaborators

    • terkelg