Sxz Reference Implementation
Sxz is a hybrid vector/raster binary image format designed for low-entropy(non-photographic) images. Sxz can attain superior compression over PNG in some cases, but not all due to the immaturity of the encoder. Two decoders are provided in C# and Javascript for demonstration.The Sxz Reference Implementation is released under LGPL license. The Sxz Polyfill in Javascript is released under MIT license. The Polyfill demos are released on CC0 license.
Sxz is a patent-unecumbered, royalty free image format.
Sxz draws heavily from PNG. It has no built in compression relying on an outside mechanism such as gzip. It uses paletted index only color storage, but allows for multiple palettes per image. Each image consists of one or more frames with one or more chunks in each frame. The interpretation of each frame is left to the decoder. Sxz supports two important features of responsive imaging. It can do clickable image maps using the data in the image itself without the need for an extra map file. It can also scale parts of itself differently to achieve art direction. By splitting the image into separate frames, each frame can be treated differently by the decoder. Tested on Firefox 29+ and Chrome 36 Demos are located in the Polyfill folder along with the Javascript raster sxz.js.