OpenCV - OpenCV is the world's biggest computer vision library
imgix - Real-time Image Processing. Resize, crop, and process images on the fly, simply by changing their URLs.
Microsoft Computer Vision API - Extract rich information from images and analyze content with Computer Vision, an Azure Cognitive Service.
Cloudimage - Cloudimage.io is the easiest way to resize, store, and deliver your images to your customers through a rocket fast CDN.
Google Vision AI - Cloud Vision API provides a comprehensive set of capabilities including object detection, ocr, explicit content, face, logo, and landmark detection.
Sirv - Dynamic image processing, hosting and rich-media for retailers and eCommerce.