图像大小调整为最大高度，但页面溢出

img {
  max-height: 100%;
  max-width: 100%;
  overflow: hidden;
}

window.onload = function() {
  var image = document.getElementById('image');
  var maxWidth = window.innerWidth;
  var maxHeight = window.innerHeight;
  
  var width = image.width;
  var height = image.height;
  
  var ratio = Math.min(maxWidth / width, maxHeight / height);
  
  image.style.width = width * ratio + 'px';
  image.style.height = height * ratio + 'px';
}