Photo Picker+ a new free library for iOS that replaces the native photo chooser to let users select a photo from Facebook, Picasa, Flickr, or Instagram, in addition to the local Camera Roll or Photo Stream. It returns the photo in the exact same format as the native image picker on iOS and Android so it is very simple to integrate.

The GPUImage framework is a BSD-licensed iOS library that lets you apply GPU-accelerated filters and other effects to images, live camera video, and movies. In comparison to Core Image (part of iOS 5.0), GPUImage allows you to write your own custom filters, supports deployment to iOS 4.0, and has a simpler interface. However, it currently lacks some of the more advanced features of Core Image, such as facial detection.

Dragonfly is a new(-ish!) ruby gem for handling images and other content in Ruby web apps (including Rails). “What – another one?!”.. I hear you exclaim. While using Dragonfly in Rails is similar to using, say, Paperclip, a significant difference is that images are generated on the fly, as opposed to when uploaded.

Grabs the dominant color or a representative color palette from an image. Uses javascript and canvas.

is is an image editor written using WebGL for HackNY 2011. WebGL is GPU programming for the web, and allows JavaScript web applications to attain performance that wouldn't otherwise be possible.

IOS UIImage processing functions using the vDSP/Accellerate framework for speed.

ImageOptim optimizes images — so they take up less disk space and load faster — by finding best compression parameters and by removing unnecessary comments and color profiles. It handles PNG, JPEG and GIF animations.

[pimiø] is a Javascript library to apply photo effects to the images on a website. It's currently under development but you can look at the source code of this page if you're interested.

Image Processing Lab is a simple tool for image processing, which includes different filters and tools to analyze images available in the AForge.NET framework. It's easy to develop your own filters and to integrate them with the code or use the tools in your own application.