This example uses OpenLayers v10.9.0. The latest is v.
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#### Zoomify

zoomify 1 deepzoom 1 IIP 1 pixel 2 projection 14

#####

Example of a Zoomify source.

Zoomify is a format for deep-zooming into high resolution images. This example shows how to use the Zoomify source with a pixel projection. Internet Imaging Protocol (IIP) with JTL extension is also handled.

##### main.js

    import Map from 'ol/Map.js';
    import View from 'ol/View.js';
    import TileLayer from 'ol/layer/Tile.js';
    import Zoomify from 'ol/source/Zoomify.js';

    const imgWidth = 4000;
    const imgHeight = 3000;

    const zoomifyUrl = 'https://ol-zoomify.surge.sh/zoomify/';

    const source = new Zoomify({
      url: zoomifyUrl,
      size: [imgWidth, imgHeight],
      crossOrigin: 'anonymous',
      zDirection: -1, // Ensure we get a tile with the screen resolution or higher
    });
    const extent = source.getTileGrid().getExtent();

    const retinaPixelRatio = 2;
    const retinaSource = new Zoomify({
      url: zoomifyUrl,
      size: [imgWidth, imgHeight],
      crossOrigin: 'anonymous',
      zDirection: -1, // Ensure we get a tile with the screen resolution or higher
      tilePixelRatio: retinaPixelRatio, // Display retina tiles
      tileSize: 256 / retinaPixelRatio, // from a higher zoom level
    });

    const layer = new TileLayer({
      source: source,
    });

    const map = new Map({
      layers: [layer],
      target: 'map',
      view: new View({
        // adjust zoom levels to those provided by the source
        resolutions: layer.getSource().getTileGrid().getResolutions(),
        // constrain the center: center cannot be set outside this extent
        extent: extent,
        constrainOnlyCenter: true,
      }),
    });
    map.getView().fit(extent);

    const control = document.getElementById('zoomifyProtocol');
    control.addEventListener('change', function (event) {
      const value = event.currentTarget.value;
      if (value === 'zoomify') {
        layer.setSource(source);
      } else if (value === 'zoomifyretina') {
        layer.setSource(retinaSource);
      }
    });

##### index.html

    <!DOCTYPE html>
    <html lang="en">
      <head>
        <meta charset="UTF-8">
        <title>Zoomify</title>
        <link rel="stylesheet" href="node_modules/ol/ol.css">
        <style>
          .map {
            width: 100%;
            height: 400px;
          }
        </style>
      </head>
      <body>
        <div id="map" class="map"></div>
        <div class="controls">
          <select id="zoomifyProtocol">
            <option value="zoomify">Zoomify</option>
            <option value="zoomifyretina">Zoomify Retina</option>
          </select>
        </div>

        <script type="module" src="main.js"></script>
      </body>
    </html>

##### package.json

    {
      "name": "zoomify",
      "dependencies": {
        "ol": "10.9.0"
      },
      "devDependencies": {
        "vite": "^3.2.3"
      },
      "scripts": {
        "start": "vite",
        "build": "vite build"
      }
    }