MapA11y

MapA11y is a React-based accessibility tool for map applications and general
websites that provides various color filters to enhance visualization for people
with visual impairments (e.g., Protanomaly and Tritanomaly). The filters are
optimized for integration into mapping applications like OpenLayers.
This plugin is still under constant development
Features - February 2025
- Protanomaly Filter: Adjusts colors for individuals with Protanomaly (red
color blindness).
- Deuteranomaly Filter: Adjusts colors for individuals with Deuteranomaly
(green color blindness).
- Tritanomaly Filter: Adjusts colors for individuals with Tritanomaly (blue
color blindness).
- Grayscale Filter: Converts the visualization into grayscale.
Installation
First, install the package and its peer dependencies in your project:
npm install @terrestris/mapa11y
Then import and use the FilterMenu component in your application:
import { FilterMenu } from '@terrestris/mapa11y';
import '@terrestris/mapa11y/dist/mapa11y.css';
const App = () => {
return (
<>
{/* Your other components */}
<FilterMenu />
</>
);
};
export default App;
To add the mapa11y translations to an exisitng i18n instance use
import { addTranslations } from '@terrestris/mapa11y';
await addTranslations(i18n);
Otherwise, the plugin uses its own i18n instance.
The filter menu is then displayed in the application and can be applied to the
content of the entire website.
Usage
Basic Integration
To integrate the accessibility filters into your React application, import the
FilterMenu component.
Development
Local Setup
To run the project locally, clone the repository and install dependencies:
git clone git@github.com:terrestris/mapa11y.git
cd mapa11y
npm install
npm run dev
Then open http://localhost:5173/ in your browser. Here the plugin is
integrated into a map application.
Build
To build the package:
npm run build
Further Details
See also
https://developer.mozilla.org/en-US/docs/Web/SVG/Element/feColorMatrix and
https://www.ashleysheridan.co.uk/blog/Testing+Colour+Blindness+Effects+Online+with+SVG+Filters
for further details about SVG matrix and color blindness.
See also
https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/color-blindness/types-color-vision-deficiency
for more information about the types of color vision deficiency.
License
This project is licensed under the BSD 2-Clause License. See the
LICENSE file for details.
Logo source:
ISO 7001 PI PF 049
This file is made available under the Creative Commons CC0 1.0 Universal Public
Domain Dedication.