GeoTIFF image manipulation

Channel mapping

R

G

B

100% © Data provided by the European Space Agency

import { MapControls } from "three/examples/jsm/controls/MapControls.js";

import Extent from "@giro3d/giro3d/core/geographic/Extent.js";
import GeoTIFFSource from "@giro3d/giro3d/sources/GeoTIFFSource.js";
import Instance from "@giro3d/giro3d/core/Instance.js";
import ColorLayer from "@giro3d/giro3d/core/layer/ColorLayer.js";
import Interpretation from "@giro3d/giro3d/core/layer/Interpretation.js";
import Map from "@giro3d/giro3d/entities/Map.js";
import Inspector from "@giro3d/giro3d/gui/Inspector.js";

function bindNumericalDropDown(id, onChange) {
  const element = document.getElementById(id);
  if (!(element instanceof HTMLSelectElement)) {
    throw new Error(
      "invalid binding element: expected HTMLSelectElement, got: " +
        element.constructor.name,
    );
  }

  element.onchange = () => {
    onChange(parseInt(element.value));
  };

  const callback = (v) => {
    element.value = v.toString();
    onChange(parseInt(element.value));
  };

  return [callback, parseInt(element.value), element];
}

Instance.registerCRS(
  "EPSG:32611",
  "+proj=utm +zone=11 +datum=WGS84 +units=m +no_defs +type=crs",
);

const extent = new Extent("EPSG:32611", 666285, 668533.5, 3997174, 3998444);
const center = extent.centerAsVector3();

const instance = new Instance({
  target: "view",
  crs: extent.crs,
  backgroundColor: 0x0a3b59,
});

instance.view.camera.position.set(center.x, center.y, 2500);

const controls = new MapControls(instance.view.camera, instance.domElement);
controls.enableDamping = true;
controls.dampingFactor = 0.2;
controls.target.set(center.x, center.y + 1, center.z);
instance.view.setControls(controls);

const map = new Map({ extent });

instance.add(map);

// Data coming from the same source as
// https://openlayers.org/en/latest/examples/cog-math-multisource.html
const source = new GeoTIFFSource({
  url: "https://3d.oslandia.com/cog_data/20200428_211318_ssc8d1_0017_pansharpened.cog.tif",
  crs: extent.crs,
  channels: [0, 1, 2],
});

const layer = new ColorLayer({
  name: "color-layer",
  source,
  extent,
  interpretation: Interpretation.CompressTo8Bit(0, 900),
});

map.addLayer(layer);

bindNumericalDropDown("r-channel", (v) => {
  source.channels[0] = v;
  source.update();
});
bindNumericalDropDown("g-channel", (v) => {
  source.channels[1] = v;
  source.update();
});
bindNumericalDropDown("b-channel", (v) => {
  source.channels[2] = v;
  source.update();
});

Inspector.attach("inspector", instance);

<!doctype html>
<html lang="en">
  <head>
    <title>GeoTIFF image manipulation</title>
    <meta charset="UTF-8" />
    <meta name="name" content="cog_channel_mapping" />
    <meta
      name="description"
      content="Select which bands to view on GeoTIFFs with multiple bands."
    />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />

    <link rel="icon" href="https://giro3d.org/images/favicon.svg" />
    <link
      href="https://giro3d.org/assets/bootstrap-custom.css"
      rel="stylesheet"
    />
    <script src="https://giro3d.org/assets/bootstrap.bundle.min.js"></script>
    <link
      rel="stylesheet"
      type="text/css"
      href="https://giro3d.org/next/examples/css/example.css"
    />
  </head>

  <body>
    <div id="view" class="m-0 p-0 w-100 h-100"></div>
    <div
      id="inspector"
      class="position-absolute top-0 start-0 mh-100 overflow-auto"
    ></div>

    <div class="side-pane-with-status-bar">
      <div class="card">
        <div class="card-header">Channel mapping</div>

        <div class="card-body">
          <div class="input-group mb-3">
            <label class="input-group-text" for="r-channel">R</label>
            <select class="form-select" id="r-channel" autocomplete="off">
              <option value="0" selected>Band 1</option>
              <option value="1">Band 2</option>
              <option value="2">Band 3</option>
              <option value="3">Band 4</option>
            </select>
          </div>
          <div class="input-group mb-3">
            <label class="input-group-text" for="g-channel">G</label>
            <select class="form-select" id="g-channel" autocomplete="off">
              <option value="0">Band 1</option>
              <option value="1" selected>Band 2</option>
              <option value="2">Band 3</option>
              <option value="3">Band 4</option>
            </select>
          </div>
          <div class="input-group">
            <label class="input-group-text" for="b-channel" autocomplete="off"
              >B</label
            >
            <select class="form-select" id="b-channel">
              <option value="0" selected>Band 1</option>
              <option value="1">Band 2</option>
              <option value="2" selected>Band 3</option>
              <option value="3">Band 4</option>
            </select>
          </div>
        </div>
      </div>
    </div>

    <script type="module" src="index.js"></script>
    <script>
      /* activate popovers */
      const popoverTriggerList = [].slice.call(
        document.querySelectorAll('[data-bs-toggle="popover"]'),
      );
      popoverTriggerList.map(
        // bootstrap is used as script in the template, disable warning about undef
        // eslint-disable-next-line no-undef
        (popoverTriggerEl) =>
          new bootstrap.Popover(popoverTriggerEl, {
            trigger: "hover",
            placement: "left",
            content: document.getElementById(
              popoverTriggerEl.getAttribute("data-bs-content"),
            ).innerHTML,
            html: true,
          }),
      );
    </script>
  </body>
</html>

{
    "name": "cog_channel_mapping",
    "dependencies": {
        "@giro3d/giro3d": "git+https://gitlab.com/giro3d/giro3d.git"
    },
    "devDependencies": {
        "vite": "^3.2.3"
    },
    "scripts": {
        "start": "vite",
        "build": "vite build"
    }
}