linear-motion

HTML

<div class="linear-motion">
</div>

SCSS

.linear-motion{
  height: 300px;
  content: "";
  background-color: transparent;
    background-image: url(http://lab.risewill.co.jp/images/web-design/naminami.jpg);
    background-position: center center,center 0%;
    background-size: cover;
    animation: linear-motion 50s linear infinite;
    background-attachment: scroll,fixed;
    @keyframes linear-motion {
      0% {
           background-position: 0 0,0 0;
      }
    100% {
       background-position: 1000vw 0,0 0;
    }
  }
}