You can use Bootstrap to render images with rounded corners or as a circle. This is achieved with the .rounded-* utility classes.
<img src="image_1.png" class="rounded" alt="rounded image">
<img src="image_2.png" class="rounded-circle" alt="rounded-circle image">
<img src="image_3.png" class="img-thumbnail" alt="img-thumbnil image">
<img src="image_4.png" class="rounded-top" alt="rounded-top image">
<img src="image_5.png" class="rounded-bottom" alt="rounded-bottom image">
<img src="image_6.png" class="rounded-0" alt="rounded-0 image">
