<div class="container">
    <div class="top"></div>
    <div>
        <img src="//via.placeholder.com/400x200">
    </div>
    <div class="bottom"></div>
</div>

.container {
  position: relative;
  width: 400px;
}
.top {
  position: absolute;
  top: 0;
  border-radius: 0% 0% 100% 100%/0% 0% 200% 200%;
  background-color: blue;
  width: 100%;
  z-index: 10;
  height: 20px;
}
div.img {
  z-index: 1;
}
.bottom {
  position: absolute;
  bottom: 0;
  background-color: red;
  width: 100%;
  height: 20px;
  z-index: 10;
  border-radius: 100% 100% 0% 0% / 200% 200% 0% 0%;
}