Sirv - Dynamic image processing, hosting and rich-media for retailers and eCommerce.
Pixaven - Modern GPU-powered image processing API
Cloudimage - Cloudimage.io is the easiest way to resize, store, and deliver your images to your customers through a rocket fast CDN.
tiny.pictures - Real-time image-processing, optimization, and Content Delivery Network
imgix - Real-time Image Processing. Resize, crop, and process images on the fly, simply by changing their URLs.
Face++ - API for face detection – also detects gender, age, pose