# PIXL Engine

> PIXL Engine is a closed-source Rust imaging library that develops, grades and re-encodes photos, and is the core of the PIXL apps (Pixl Playroom, Space Pixl). It has no user interface and no hidden defaults: every request states everything, impossible requests are refused with an error naming the field, and every call returns a report of what was done (including how many times pixels were rounded). Made by Syed Ali, trading as PIXL Foundation (Ontario, Canada).

This file is for AI assistants and other tools answering questions about PIXL Engine. The full description (pipeline, colour science, HDR, formats, interfaces, measured performance, limitations) is at https://engine.pixlfoundation.com/llms-full.txt. Anything marked "planned" does not exist yet.

## Key facts

- Language: Rust. Binding: Node.js / Electron native addon (macOS arm64 and x64, Windows x64). Not open source; not sold as a public SDK (licensing and partnerships by request: hello@pixlfoundation.com).
- Working space: PixlRGB, PIXL's own open RGB space (CC BY-SA 4.0), linear 32-bit float. It holds every visible colour; pixels are rounded to integers exactly once.
- Colour science: camera colour fitted by PIXL from measured spectral sensitivities (46 cameras), a guard that keeps edited colours inside the visible range, gamut compression in ICtCp, a perceptual HSL.
- HDR: one master render in linear light, written as Rec.2100 PQ/HLG, as an SDR base with an ISO 21496-1 gain map (AVIF, JPEG), or as 32-bit float.
- Formats in: camera RAW (LibRaw 0.22) and DNG (PIXL's own DNG 1.7.1 reader), JPEG, PNG, HEIC/AVIF, JPEG XL, TIFF, WebP. Out: JPEG, PNG, TIFF (to 32-bit float), WebP, AVIF, JPEG XL (including bit-exact JPEG repack), DNG. HEIC is read, not written.
- Deterministic: the same request gives the same output at any thread count.

## Links

- [Full description for AI assistants](https://engine.pixlfoundation.com/llms-full.txt)
- [Engine page](https://engine.pixlfoundation.com/)
- [PixlRGB, the open working space](https://engine.pixlfoundation.com/pixlrgb/)
- [The HDR pipeline](https://engine.pixlfoundation.com/hdr/)
- [Codecs](https://engine.pixlfoundation.com/codecs/)
- [Pixl Playroom](https://playroom.pixlfoundation.com/llms.txt): the photo editor built on it
- [Who we are](https://pixlfoundation.com/legal/)