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                <canvas id="myCanvas" />


                canvas {
  border: 1px solid grey;


                let loadImageOnCanvasAndResizeCanvasToFitImage = (canvas, imageUrl) => {
  // Get the 2D Context from the canvas
  let ctx = canvas.getContext("2d");

  // Create a new Image
  let img = new Image();

  // Setting up a function with the code to run after the image is loaded
  img.onload = () => {
    // Once the image is loaded, we will get the width & height of the image
    let loadedImageWidth = img.width;
    let loadedImageHeight = img.height;

    // Set the canvas to the same size as the image.
    canvas.width = loadedImageWidth;
    canvas.height = loadedImageHeight;

    // Draw the image on to the canvas.
    ctx.drawImage(img, 0, 0);

  // Now that we have set up the image "onload" handeler, we can assign
  // an image URL to the image.
  img.src = imageUrl;

// Run code after the page is loaded
document.addEventListener("DOMContentLoaded", () => {
  // Setting up the canvas
  let theCanvas = document.getElementById("myCanvas");

  // Some image URL..
  let imageUrl =

  // Load image on the canvas & re-size the canvas based on the image size
  loadImageOnCanvasAndResizeCanvasToFitImage(theCanvas, imageUrl);