画像

<div class="box">
  <p class="img">
    <img src="hogehoge.png" alt="hoge" />
  </p>
  <p class="title">
    テストテキストです。
  </p>  
</div>

<style>
.box{
  width: 80px;
  height: 80px;
  position: relative;
}

.img{
  width: 100%;
  height: 100%;
  position: relative;
}

.img:after{
  width: 100%;
  height: 100%;
  position: absolute;
  content: '';
  display: block;
  top: 0;
  right: 0;
  background: -moz-linear-gradient(top, rgba(255,255,255,0) 0%, rgba(51,51,51,0) 35%, rgba(51,51,51,0.2) 100%); /* FF3.6-15 */
  background: -webkit-linear-gradient(top, rgba(255,255,255,0) 0%,rgba(51,51,51,0) 35%,rgba(51,51,51,0.2) 100%); /* Chrome10-25,Safari5.1-6 */
  background: linear-gradient(to bottom, rgba(255,255,255,0) 0%,rgba(51,51,51,0) 35%,rgba(51,51,51,0.2) 100%); /* W3C, IE10+, FF16+, Chrome26+, Opera12+, Safari7+ */
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#00ffffff', endColorstr='#33333333',GradientType=0 );
}

.title{
  width: 100%;
  position: absolute;
  left: 0;
  bottom: 0;
}
</style>