wasm-go-image-to-ascii

README

wasm-go-image-to-ascii

Convert image to ascii on the web using Webassembly ported from golang. Golang Library: image2ascii

Building wasm

cd ./wasm

make build

Install goexec

go get -v -u github.com/shurcooL/goexec

make start-server

This will start the server at port 8080

Usage

To convert image to ascii the function convert is exposed from go to javascript. It takes image Uint8Array and configuration to convert to ascii.

array = new Uint8Array(arrayBuffer);

let text = convert(array, {
	fixedWidth: 140
	fixedHeight: 20
	colored: false
	reversed: false
}) // this returns ansi characters

// converting in to html
var ansi_up = new AnsiUp(); // https://github.com/drudru/ansi_up

var html = ansi_up.ansi_to_html(txt);

• Reading image in javascript: FileReader API
• Image to Ascii configuration: image2ascii
• Ansi to html: AnsiUp

Example Use case

// Instantiate wasm
const go = new Go();
WebAssembly.instantiateStreaming(fetch("main.wasm"), go.importObject).then(
  (result) => {
    go.run(result.instance);
  }
);
// Listen to file change i.e when user selects a file to upload.
document.querySelector("#file").addEventListener(
  "change",
  function () {
    const reader = new FileReader();
    reader.onload = function () {
      const arrayBuffer = this.result,
        array = new Uint8Array(arrayBuffer);
      // Call wasm exported function
      const txt = convert(
        array,
        JSON.stringify({
          fixedWidth: 100,
          colored: true,
          fixedHeight: 40,
        })
      );
      const ansi_up = new AnsiUp();
      const html = ansi_up.ansi_to_html(txt);
      const cdiv = document.getElementById("console");
      cdiv.innerHTML = html;
    };
    reader.readAsArrayBuffer(this.files[0]);
  },
  false
);

License

This project is under the MIT License. See the LICENSE file for the full license text.