@chriscdn/exif

Motivation

EXIF metadata can be inconsistent, particularly when it comes to timestamps and location data. Many images store dates in local time without specifying a time zone, making it difficult to determine precisely when a photo was taken.

This library, built on exifreader, extracts metadata from photos and aims to normalize:

• Location – Extracts GPS coordinates and identifies the time zone.
• Date & Time – Uses the time zone to determine the UTC time of the photo.
• Dimensions – Retrieves the image width and height.

Attempts are made to normalize the results from exifr, which can vary among image types.

Note: This package has only been tested with HEIC, PNG, and JPG files.

This package addresses a personal use case, but perhaps someone else will find it useful.

Installation

Using npm:

npm install @chriscdn/exif

Using yarn:

yarn add @chriscdn/exif

Usage

import { exif, type ExifData } from "@chriscdn/exif";

// Node.js
const image = "./path/to/file.jpg";
const data: ExifData = await exif(image);

// Browser
const file: File;
const data: ExifData = await exif(file);

The ExifData return value

This is an opinionated return value which addresses my use case. Pull requests are welcome if you require other fields to be added.

Fields are null when the data isn't available.

• latitude (number|null): Decimal degrees, rounded to 6 significant digits.
• longitude (number|null): Decimal degrees, rounded to 6 significant digits.
• timeZone (string|null): Time zone derived from latitude/longitude.
• localTime (string|null): ISO 8601 local time (e.g., "2023-01-01T09:45:64").
• timestamp (number|null): Unix timestamp in milliseconds.
• title (string|null): Image title.
• caption (string|null): Image description.
• width (number): Image width in pixels.
• height (number): Image height in pixels.
• city (string|null): City where taken.
• state (string|null): State or region where taken.
• country (string|null): Country where taken.
• countryCode (string|null): ISO country code.
• location (string|null): Location.
• rating (number|null): Numeric rating.
• mimetype (string|null): MIME type (e.g., image/jpeg).
• keywords (string[]): Associated tags; empty array if none.

License

MIT