jsfeat is a computer vision library with a rich and varied feature set. It can perform tasks such as: edge detection, image processing (grayscale, blur, etc.), corner detection, object detection, optical flow detection, etc.
Code Libraries: Image processing
CamanJS is a canvas manipulation library offering many tools for pixel-level canvas manipulation. It can crop and resize images, apply blending modes and a host of filters such as: gamma, greyscale, noise, hue, saturation, etc. Unlike with CSS3 filters, the resulting image can be saved. The library can be used in the browser or in a Node.js compatible environment.