This example uses OpenLayers v10.9.0. The latest is v.
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#### GeoTIFF tile pyramid

cog 15 tilepyramid 1 stac 2

#####

Rendering a COG tile pyramid as layer group.

Data from a Cloud Optimized GeoTIFF (COG) tile pyramid can be rendered as a set of layers. In this example, a pyramid of 3-band GeoTIFFs is used to render RGB data. The `ol/source.sourcesFromTileGrid` helper function creates sources from this pyramid on demand. The GeoTIFFs used by those sources have a resolution range that matches the range of a single z of the pyramid tile grid.

##### main.js

    import Map from 'ol/Map.js';
    import View from 'ol/View.js';
    import WebGLTileLayer from 'ol/layer/WebGLTile.js';
    import {sourcesFromTileGrid} from 'ol/source.js';
    import GeoTIFF from 'ol/source/GeoTIFF.js';
    import TileGrid from 'ol/tilegrid/TileGrid.js';

    // Metadata from https://s2downloads.eox.at/demo/EOxCloudless/2019/rgb/2019_EOxCloudless_rgb.json

    // Tile grid of the GeoTIFF pyramid layout
    const tileGrid = new TileGrid({
      extent: [-180, -90, 180, 90],
      resolutions: [0.703125, 0.3515625, 0.17578125, 8.7890625e-2, 4.39453125e-2],
      tileSizes: [
        [512, 256],
        [1024, 512],
        [2048, 1024],
        [4096, 2048],
        [4096, 4096],
      ],
    });

    const pyramid = new WebGLTileLayer({
      sources: sourcesFromTileGrid(
        tileGrid,
        ([z, x, y]) =>
          new GeoTIFF({
            sources: [
              {
                url: `https://s2downloads.eox.at/demo/EOxCloudless/2019/rgb/${z}/${y}/${x}.tif`,
              },
            ],
          }),
      ),
    });

    const map = new Map({
      target: 'map',
      layers: [pyramid],
      view: new View({
        projection: 'EPSG:4326',
        center: [0, 0],
        zoom: 0,
        showFullExtent: true,
      }),
    });

##### index.html

    <!DOCTYPE html>
    <html lang="en">
      <head>
        <meta charset="UTF-8">
        <title>GeoTIFF tile pyramid</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>

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

##### package.json

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