<!DOCTYPE html>
<div style="position: absolute; top: 10px; left: 10px; width: 200px; height: 400px; outline: 1px solid blue;">
    <img style="background-color: yellow; width: auto; height: auto; max-width: 100%; max-height: 100%;" src="data:image/svg+xml,<svg width='600' height='300' xmlns='http://www.w3.org/2000/svg'><rect x='0' y='0' width='600' height='300'></rect></svg>">
</div>