css 图片上下左右居中且不变形

css:

.imgBox {
    width: 164px;
    display: block;
    height: 164px;
    text-align: center;
    border: 1px solid #bfbfbf;
}
.imgBox img {
    max-width: 100%;
    max-height: 100%;
    display: inline-block;
    vertical-align: middle;
}

image.png