Exoquant 0.1.0

Exoquant is a very high quality image quantization library written in Rust featuring code for basic color quantization, K-Means palette optimization and remapping and dithering with Floyd-Steinberg and ordered ditherers.

This version of the library is a much improved rewrite of a C library of the same name written back in 2004.

Basic API:

For simple use cases, there is a convenience function that simply takes true color image data + a few options as input and returns the palette and indexed image data as output:

```rust use exoquant::*; let image = testdata::test_image();

let (palette, indexeddata) = convertto_indexed(&image.pixels, image.width, 256, &optimizer::KMeans, &ditherer::FloydSteinberg::new()); ```

Low-Level API:

The low-level API gives you full control over the quantization workflow. It allows for use-cases like:

• only create a palette and do the remapping in your own custom code
• remap images to an existing palette or one created with a different library
• generating a single palette for multiple input images (or, say, frames of a GIF)
• implement your own custom ditherer (also usable with the basic API)

Using the low-level API to quantize an image looks like this:

```rust use exoquant::*; use exoquant::optimizer::Optimizer;

let image = testdata::test_image();

let histogram = image.pixels.iter().cloned().collect();

let colorspace = SimpleColorSpace::default(); let optimizer = optimizer::KMeans; let mut quantizer = Quantizer::new(&histogram, &colorspace); while quantizer.numcolors() < 256 { quantizer.step(); // very optional optimization, !very slow! // you probably only want to do this every N steps, if at all. if quantizer.numcolors() % 64 == 0 { quantizer = quantizer.optimize(&optimizer, 4); } }

let palette = quantizer.colors(&colorspace); // this optimization is more useful than the above and a lot less slow let palette = optimizer.optimize_palette(&colorspace, &palette, &histogram, 16);

let ditherer = ditherer::FloydSteinberg::new(); let remapper = Remapper::new(&palette, &colorspace, &ditherer); let indexed_data = remapper.remap(&image.pixels, image.width); ```