Crate a_sixel

Expand description

A-Sixel library for encoding sixel images.

§Basic Usage

use a_sixel::ADUSixelEncoder;
use image::RgbImage;

let img = RgbImage::new(100, 100);
println!("{}", <ADUSixelEncoder>::encode(&img));

§Choosing an Encoder

I want fast encoding with good quality:
- Use ADUSixelEncoder
- BitSixelEncoder can also produce pretty good results for 256 colors depending on the image while being over 10x faster.
I’m time constrained:
- Use ADUSixelEncoder or BitSixelEncoder. You can customize ADU by lowering the STEPS parameter to run faster if necessary while still getting good results.
I’m really time constrained and can sacrifice a little quality:
- Use BitSixelEncoder<NoDither>.
I want high quality encoding, and don’t mind a bit more computation:
- Use FocalSixelEncoder.
- This matters a lot less if you’re not crunching the palette down below 256 colors.
- Note that this an experimental encoder. It will likely produce better results than just ADUSixelEncoder, but it may not always do so. On the test images, for my personal preferences, I think it’s slightly better - particularly at small palette sizes.
  
  How it works
  
  Under the hood, it is a modified version of the ADUSixelEncoder that uses a weighted selection algorithm for its sample pixels. These weights are determined based on saliency maps and measures of statistical noise in the image.
  
  In addition to the weighted selection, the distance metric used to determine which cluster to place a pixel into also incorporates the weight. Similar pixels with different weights will be nudged towards clusters with similar weights. This is a mild effect, but it seems to improve things over basic clustering when there are a lot of similar colors in an image.

Modules§

dither

Structs§

ADUPaletteBuilder: Use Adaptive Distributive Units to “learn” the image’s color properties and select palette entries.
BitPaletteBuilder: Encodes a palette by bucketing bit ranges into a power of two number of buckets. This is very fast and produces ok results for most images at larger palette sizes (e.g. 256).
FocalPaletteBuilder: Use weighted pixels based on the image’s spectral properties to select input to ADU.
MedianCutPaletteBuilder: https://en.wikipedia.org/wiki/Median_cut
SixelEncoder: The main type for performing sixel encoding.

Traits§

PaletteBuilder

Crate a_sixelCopy item path

§Basic Usage

§Choosing an Encoder

Modules§

Structs§

Traits§

Type Aliases§

Crate a_sixel