Result Size: 625 x 534
x
 
<!DOCTYPE html>
<html>
<head>
<style>
body {
  background-image: url('img_tree.png');
  background-repeat: no-repeat;
}
</style>
</head>
<body>
<button type="button" onclick="myFunction()">定位背景图片</button>
<script>
function myFunction() {
  document.body.style.backgroundPosition="top right"; 
}
</script>
</body>
</html>