CODE EXAMPLE FOR CSS

text background image css

.card-title {
  text-align: center;
  font-size: 50px;
  line-height: 50px;
  background-color: white;
  padding: 10% 0%;
  color: #000;
  /*mix-blend-mode: color-dodge;*/
  mix-blend-mode: screen;
}

/* HTML */
<div class="row">
  <div class="card bg-dark text-white">
    <img src="https://images.pexels.com/photos/1005417/pexels-photo-1005417.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=100&w=240" class="card-img" alt="...">
    <div class="card-img-overlay">
      <h5 class="card-title">B</h5>    
    </div>
  </div>
</div>