I do not understand what result is needed, something like this?
.slanted-container {
--deg: 10deg;
--radius: 10px;
}
.slanted {
position: relative;
border: 4px solid purple;
width: 200px;
height: 100px;
transform: skew(var(--deg));
border-radius: var(--radius);
overflow: hidden;
}
.slanted2 {
border: 4px solid purple;
width: 200px;
height: 100px;
transform: skew(var(--deg));
border-radius: var(--radius);
overflow: hidden;
background: url(https://www.esiteanalytics.com/wp-content/uploads/GeographicBarrierMedian.jpg);
background-size: cover;
}
.slanted img {
display: block;
max-width: 100%;
}
<div class="slanted-container">
<div class="slanted">
<img src="https://www.esiteanalytics.com/wp-content/uploads/GeographicBarrierMedian.jpg" />
</div>
<div class="slanted2">
</div>
</div>