I use
<img class="fullpage" alt="cover" [... etc] />
with
.fullpage {
height: 100%;
max-width: 100%
}
Alternatively, you can use svg:
Code:
<div>
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" height="100%" preserveAspectRatio="xMidYMid meet" version="1.1" viewBox="0 0 600 800" width="100%">
<image height="800" width="600" xlink:href="../Images/cover.jpeg"></image>
</svg>
</div>