Rounded Corners
The .rounded class adds rounded corners to an image:
Circle
The .rounded-circle class shapes the image to a circle:
Thumbnail
The .img-thumbnail class creates a thumbnail of the image:
Aligning images
Use the float classes to float the image to the left or to the right:
Centered Image
Center an image by adding the utility classes .mx-auto (margin:auto) and .d-block (display:block) to the image: