Css Force Image Resize and Keep Aspect Ratio

img {  display: block;  max-width:230px;  max-height:95px;  width: auto;  height: auto;}

<p>This image is originally 400x400 pixels, but should get resized by the CSS:</p><img width="400" height="400" src="http://i.stack.imgur.com/aEEkn.png">

Force an image to fit and keep aspect ratio

You can try CSS3 object-fit, and see browser support tables.

CSS3 object-fit/object-position Method of specifying how an object (image or video) should fit inside
its box. object-fit options include "contain" (fit according to aspect
ratio), "fill" (stretches object to fill) and "cover" (overflows box
but maintains ratio), where object-position allows the object to be
repositioned like background-image does.

JSFIDDLE DEMO

.container {  width: 200px; /*any size*/  height: 200px; /*any size*/}
.object-fit-cover {  width: 100%;  height: 100%;  object-fit: cover; /*magic*/}

<div class="container">  <img class="object-fit-cover" src="https://i.stack.imgur.com/UJ3pb.jpg"></div>

max-width:100%;
max-height:100%;

img {
    max-width: 100%;
    max-height: 100%;
}

.portrait {
    height: 80px;
    width: 30px;
}

.landscape {
    height: 30px;
    width: 80px;
}

.square {
    height: 75px;
    width: 75px;
}

Portrait Div
<div class="portrait">
    <img src="http://i.stack.imgur.com/xkF9Q.jpg">
</div>

Landscape Div
<div class="landscape">
    <img src="http://i.stack.imgur.com/xkF9Q.jpg">
</div>

Square Div
<div class="square">
    <img src="http://i.stack.imgur.com/xkF9Q.jpg">
</div>