qoi-img

Typescript bindings for encoding an decoding the Quite Ok Image format. Since this uses the QOIxx c++ library, instead of javascript, it is much faster than other libraries. It also uses qoi-stream for the streaming api, which is written in C. So this library is also very fast.

https://qoiformat.org/

Documentation

Encoding

You can encode an image to the qoi-img format by using the QOIEncode function. The pixels are ordered as either RGB or RGBA, depending on what you specify in the channels parameter.

function QOIencode(
  pixels: Buffer,
  options: {
    width: number;
    height: number;
    channels: QOIChannels;
    colorspace?: QOIColorSpace;
  },
) => Buffer;

Decoding

Decoding is just as easy. You can decode an image by using the QOIDecode function. If you leave the convertChannels parameter empty, the channels will automatically be inferred from the image. However if you set it to either RGB or RGBA, it will convert the image to the correct channels.

function QOIDecode(data: Buffer, convertChannels?: QOIChannels) => {
  pixels: Buffer;
  width: number;
  height: number;
  channels: QOIChannels;
  colorspace: QOIColorSpace;
}

Stream Encoding

You can also encode a stream of pixels into a qoi image using the streaming api. This is useful if you want to encode a large image without having to load it all into memory.

const input = fs.createReadStream("input.rgb");
const output = fs.createWriteStream("output.qoi");

const encoder = new QOIStreamEncoder({
  width: 64,
  height: 64,
  channels: QOIChannels.RGB,
  colorspace: QOIColorSpace.SRGB,
});

input.pipe(encoder).pipe(output);

const info = encoder.getInfo();

console.log("Width:", info.width);
console.log("Height:", info.height);
console.log("Channels:", info.channels);
console.log("Colorspace:", info.colorspace);

Stream Decoding

The streaming api is also available for decoding qoi images. Here you can also override the channels to either add or remove the alpha channel.

const input = fs.createReadStream("input.qoi");
const output = fs.createWriteStream("output.rgba");

const decoder = new QOIStreamDecoder(QOIChannels.RGBA);

input.pipe(decoder).pipe(output);

const info = decoder.getInfo();

console.log("Width:", info.width);
console.log("Height:", info.height);
console.log("Channels:", info.channels);
console.log("Colorspace:", info.colorspace);

Release notes

• [v2.1.2]
  • Fix build for MacOS and Windows
• [v2.1.1]
  • Improve documentation
  • Update dependencies
• [v2.1.0]
  • Add sharp integration for streams
• [v2.0.0]
  • Added support for the streaming api
  • Updated qoixx
  • Updated dependencies
• [v1.2.0]
  • Update dependencies
  • Remove building with -march=native
• [v1.1.0]
  • Add RGB/RGBA conversion, add tests
• [v1.0.0]
  • Initial release