ishihara

Generate Ishihara test plate images for color vision deficiency testing.

Installation

npm i @mtillmann/ishihara

Usage

The async ishihara function takes an options-object (see below) and returns an instance of CirclePacker from the circlepacker-package.

Use any of CirclePacker's output helper methods to render the image.

You can pass a CirclePacker-options-object inside the options.circlePackerOptions property.

Using a Bundler

import ishihara from '@mtillmann/ishihara';

const image = (await ishihara()).asCanvas();
document.body.appendChild(image);
//or
ishihara().then((image) => {
  document.body.appendChild(image.asCanvas());
});

Module Script Tag

<script type="module">
  import ishihara from '.../@mtillmann/ishihara/dist/index.bundle.js';

  const image = (await ishihara()).asCanvas();
  document.body.appendChild(image);
</script>

Classic Script Tag

<script src=".../@mtillmann/ishihara/dist/index.bundle.iife.js"></script>
<script>
  const image = (await ishihara()).asCanvas();
  document.body.appendChild(image);
</script>

Options

The ishihara function takes an options object with the following properties:

| Option | Type | Default | Description | | ------------------- | ---------------------------- | ----------------------- | ------------------------------------------------------------------------------ | | circlePackerOptions | Partial<circlePackerOptions> | {} | Options for the CirclePacker | | textColors | string[] | ['#ffffff'] | Colors for the text | | backgroundColors | string[] | ['#000000'] | Colors for the background | | text | string | '8' | Text to display, max 2 characters | | font | string | 'bold 256px sans-serif' | Font for the text (see) | | radius | number|'auto' | 'auto' | Radius of the circles, 'auto' will calculate the radius based on the text size | | padding | number|string | '20%' | Padding around the text, can be a number or a percentage | | margin | number|string | '10%' | Margin around the image, can be a number or a percentage | | debug | boolean | false | renders debug image with same output api as CirclePacker |