背景の画像自動スライド・bgswitcher.js

<div class="bg-slider">
    <h1 class="bg-slider__title">BGSWITCHER DEMO PAGE</h1>
</div>

.bg-slider {
	width: 100vw;
	height: 100vh;
	background-position:center center;
	background-size: cover;
	display: flex;
	align-items: center;
	justify-content: center;
}
.bg-slider__title{
	color: #fff;
	font-size: 48px;
	line-height: 1.5;
	font-weight: bold;
	text-align:center;
	text-shadow: 1px 1px 1px #000;
}

<script src="//ajax.googleapis.com/ajax/libs/jquery/3.0.0/jquery.min.js"></script>
<script src="js/jquery.bgswitcher.js"></script>
<script>
jQuery(function($) {
    $('.bg-slider').bgSwitcher({
        images: ['img/bg1.jpg','img/bg2.jpg','img/bg3.jpg'], // 切り替える背景画像を指定
    });
});
</script>