What is tracking.js?

Tracking.js is a JavaScript library that brings computer vision capabilities into web browsers. Computer vision is the field of software that lets a program analyze and interpret what it sees in an image or video, and this library makes some of those techniques available directly in a webpage without requiring a server or any special plugins. The two main features are color tracking and object tracking. Color tracking watches a video feed and identifies areas that match a specific color, which can be used to build things like gesture-controlled interfaces where you wave a colored object to trigger actions. Object tracking uses a technique called Viola-Jones to detect faces in real-time video from a webcam. The library core is about 7 kilobytes, which is small enough to include on a webpage without meaningfully slowing it down. It works by attaching to standard HTML elements: canvas elements for static images, video elements for live camera feeds, and img elements for photos. The library reads pixel data from those elements and runs its detection algorithms against them. Browser support covers Internet Explorer 9 and later, plus current versions of Chrome, Firefox, Opera, and Safari, though live camera support depends on a browser feature (getUserMedia) with slightly narrower availability. The library can be installed through npm or Bower, or downloaded as a zip file. The README includes links to interactive demo pages showing face detection and color-based drawing applications. There is also a set of lower-level utilities available for developers who want to work directly with image processing operations like edge detection, blurring, and feature detection. The project appears to have been active primarily between 2014 and 2017, and the README links to an open issue that likely tracks the project's current maintenance status. It is released under a BSD license.