positioning bootstrap images code example
Example 1: bootstrap Aligning images
Align images with the helper float classes or text alignment classes.
block-level images can be centered using the .mx-auto margin utility class.
<img src="..." class="rounded float-left" alt="...">
<img src="..." class="rounded float-right" alt="...">
<img src="..." class="rounded mx-auto d-block" alt="...">
Example 2: bootstrap image size
.top1 {
height:390px;
background-color:#FFFFFF;
margin-top:10px;
overflow: hidden;
}
.top1 img {
height:100%;
}