Image Meta JS

An npm package to parse EXIF data from images with a simple to use interface and minimal dependencies (currently only works with JPEG images)

Getting Started

Install

using npm

npm install --save image-meta-js

Usage

The constructor expects a DataView to be passed in, DataViews can be created from ArrayBuffers that can be fetched from files many ways. For example allows running using the Node 'fs' package or FileReader in the web browser

let imageMeta = new ImageMeta(imageDataView)
let data = imageMeta.data(); // returns object of all found data

// e.g. get exposure triangle
data.FNumber      // 2.8
data.ExposureTime // 1/100
data.ISO          // 800

Node:

file = fs.readFileSync('./test/img.jpg');
let imageArrayBuffer = file.buffer
let imageDataView = new DataView(imageArrayBuffer);
let imageMeta = new ImageMeta(imageDataView)

Browser:

let reader = new FileReader();
reader.onload = () => {
  let imageArrayBuffer = reader.result;
  let imageDataView = new DataView(imageArrayBuffer);
  let imageMeta = new ImageMeta(imageDataView);
}
reader.readAsArrayBuffer(file);

The full possible tag list can be found here

Tests

Tests using Mocha and automated on commits using Travis-CI They are simple tests using images with known values and ensuring that the format handling is working as expected

License

This project is licensed under the MIT License

Useful Resources

• Image format resource - Breaks down the image binary into sections
• All possible tags resource - Lists all tags according to the spec and their types
• Sample images - sample images with some very specific data such as MakerNote section or GPS tags, useful for testing