how to write on image bootstrap code example

Example 1: bootstrap Image thumbnails

In addition to our border-radius utilities, you can use 
.img-thumbnail to give an image a rounded 1px border appearance.

<img src="..." alt="..." class="img-thumbnail">

Example 2: image on text in bootstrap

<div class="text-center">
  <img src="..." class="rounded" alt="...">
</div>