Answers for "img src bootstrap"

responsive image in bootstrap

<img src="..." class="img-responsive">

bootstrap img thumbnail

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

bootstrap img src

<img src="..." class="rounded mx-auto d-block" alt="...">

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">

bootstrap image size

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

.top1 img {
    height:100%;
}

Bootstrap turn an image into a thumbnail with Bootstrap

<img src="example.png" class="img-thumbnail">