wtf is miniwtpc?

miniwtpc, short for Wavelet Thumbnail and Preview Codec, is a small image compression format built for producing tiny thumbnails and preview images. It is written as a single header C library, similar in style to the popular stb_image libraries, so it can be dropped into a project without a build system. The format targets extremely small file sizes, from as little as 200 bytes up to about 36 kilobytes, at resolutions around 256 by 256 pixels. The main use case is generating a thumbnail small enough to fit inside a single network packet, so a user sees something on screen while a larger, higher quality preview is still downloading. The codec offers two encoding modes: a faster Huffman based mode, and a slower but more efficient mode called EBCOT-lite, which is a simplified version of a technique used in JPEG 2000. The library's C API lets you encode raw RGB or RGBA pixel data either to a target quality level or to a specific target file size, in which case it automatically searches for the quality setting that gets closest to that size. It also supports an optional chroma subsampling mode that reduces color detail slightly to save more bytes. The README includes a detailed benchmark comparing miniwtpc against JPEG, JPEG 2000, and JPEG XL at many different target file sizes, using both a numeric quality score and a visual similarity score. According to these results, miniwtpc consistently produces sharper looking images than the other formats at very small file sizes, and it also encodes and decodes faster in most cases. The README notes this test used a small dataset of about 3000 images, and that its own quantization settings are tuned specifically for these very low bitrates. The full README is longer than what was shown.