Annotating An Image In JavaScript – Annotorious
Annotorious is a simple yet feature-rich JavaScript image annotation library that adds custom comments, notes, tags to a specific part of an image.
JavaScript & CSS image marker
JavaScript Library For Annotating Images With Full-size Overlay – target.js
target.js is a pure JavaScript library used for adding custom markers and notes to images that will expand into a full-sized overlay with custom text when hover over.