bootstrap thumbnail 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.

Example 2: bootstrap Image thumbnails

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

Example 3: bootstrap image size

.top1 {
    height:390px;
    background-color:#FFFFFF;
    margin-top:10px;
    overflow: hidden;
}

.top1 img {
    height:100%;
}