GraphicsMagick vs Piio: What are the differences?
GraphicsMagick: The swiss army knife of image processing. GraphicsMagick is the swiss army knife of image processing. Comprised of 267K physical lines (according to David A. Wheeler's SLOCCount) of source code in the base package (or 1,225K including 3rd party libraries) it provides a robust and efficient collection of tools and libraries which support reading, writing, and manipulating an image in over 88 major formats including important formats like DPX, GIF, JPEG, JPEG-2000, PNG, PDF, PNM, and TIFF; Piio: Generates responsive images so you don't have to optimize. Piio automatically generates real-time responsive images for your website visitors and delivers them at maximum speed. (lazy loading feature included).
GraphicsMagick and Piio can be categorized as "Image Processing and Management" tools.