Pixelating a canvas image

pixelation.js

function.pixelate(image, canvas, context, pixelSize) {
  let wScaled, hScaled, scale;

  scale = 1/pixelSize;
  wScaled = canvas.width*scale;
  hScaled = canvas.height*scale;

  context.drawImage(image, 0, 0, wScaled, hScaled);
  context.mozImageSmoothingEnabled = false;
  context.imageSmoothingEnabled = false;
  context.drawImage(canvas, 0, 0, wScaled, hScaled, 0, 0, canvas.width, canvas.height);
}