Photo Editing SDK with Filters

I need a lightweight, drop-in software development kit that focuses first and foremost on high-quality filters and effects. The goal is to give any app the ability to load an image, choose from a curated set of real-time filters, and export the processed result without noticeable lag. Cropping, resizing, or brightness/contrast tools may be added later, so please architect the codebase to be modular and extensible. Performance matters: think GPU-accelerated rendering (Metal, OpenGL ES, WebGL, or an equivalent layer depending on your proposed tech stack) and shader-based pipelines that remain smooth even on mid-range devices. I’m flexible on whether you deliver native, cross-platform, or separate platform modules, as long as the integration experience is clean—ideally a couple of lines of code and the SDK is ready to use. To keep the project concrete, here’s what I’d like as the first release: • Fully commented source code • A concise API reference with usage examples • A small sample app demonstrating filter selection and live preview • A brief integration guide (Markdown or PDF) • Test images and basic unit tests proving the output matches the reference LUTs I’ll review against startup time, frame rate during preview, and visual fidelity of the filters. Please outline your proposed tech stack, timeline, and any previous work with image processing libraries or shaders so I can see how you’ll hit those benchmarks.