Kinetic Js
KineticJS is an HTML5 Canvas JavaScript library that extends the 2D context by enabling canvas interactivity for desktop and mobile applications.
Im.js
Image Match - Project to allow compare different images pixel by pixel with good performance
Isomer
Simple isometric graphics library for HTML5 canvas
W Paint
jQuery Paint Plugin
Noisy
A jQuery plugin that adds random noise to the background of a given element.
Proton
A particle engine for html5
J Query.black and White
Clientside grayscale images on any browser
jQuery QR Code
qrcode generation standalone (doesn't depend on external services)
Jcrop
Jcrop (official) - Image Cropping Plugin for jQuery
Obelisk.js
JavaScript Engine for Building Isometric Pixel Element with HTML5 Canvas
Pixastic
JavaScript Image Processing Library
Rimg
A responsive image solution for browsers that support mediaqueries. Pure javascript and no server-side code.
Html2canvas
Screenshots with JavaScript
Vintage JS
vintageJS - add a retro/vintage effect to images using the HTML5 canvas element
Color
JavaScript color conversion and manipulation library
Focal Point
A small set of CSS classnames to help keep images cropped on the focal point for responsive designs. Using only HTML/CSS, web authors can specify an image's focal point, which stays as the image's primary focus, while the image's available width changes on responsive webpages. Crop and re-size images depending on available width and let CSS to do all of the work, and without any JavaScript.
Drawingboard.js
A canvas based drawing app that you can integrate easily on your website.