cubecolour

Add the [zoom] shortcode to a page, post or custom post-type post. If the post has a featured image it will displayed on the page, and when you move the cursor over the image, the image will be magnified with the image viewport remains constrained to the dimensions of the original image.
on a mobile/touch device the image will also be zoomable, but as there is no hover state this is achieved by means of a pinch & zoom action.
On my site you can see a <a href="https://cubecolour.co.uk/featured-image-zoom/" title="demo of Featured Image Zoom" rel="nofollow ugc">demo</a> of the plugin.
<h4>Usage:</h4>
Ensure that your post/page has a featured image defined.
Use a [zoom] shortcode to your page.
Some optional shortcode parameters can also be used.
=size= 
The large image is used by default for the unzoomed image. Use the size parameter to use a different defined image size.
eg ‘[zoom size=thumbnail]’
=zoomsize= 
The full image is used for the zoomed overlay. This can be changed using the zoomsize shortcode parameter.
eg ‘[zoom zoomsize=large]’
The image size definitions used for the the unzoomed and zoomed images should have the same aspect ratio and cropping.
=zoomin= 
This can be used to tweak the level of zoom. The value must be a positive integer. The default is 6 so if the zoom level results in too much magnification on hover, try a lower value.
eg ‘[zoom zoomin=2]’

Featured Image Zoom

Add a [zoom] shortcode to display a zoomable featured image.

Harshit Peer

Zooom is a useful plugin to have for product images on ecommerce websites, or if you just want people to be able to zoom into an image without spawning additional overlays or popup windows that may cover your content. This plugin is developed on top of a jquery plugin <a href="http://thdoan.github.io/magnify/" rel="nofollow ugc">Magnify</a> by Tom Doan.
<h4>Shortcode Example</h4>
<pre><code>[zooom normal_url="NORMAL_IMAGE_URL" big_url="BIG_IMAGE_URL" width="200px" height="200px" disable_on_click="on|off" alt="ALT_TEXT_OF_IMAGE (OPTIONAL)" class="CSS_CLASS (OPTIONAL)"/]
</code></pre>
<h4>Attribute Details</h4>
normal_url: The Base Image URL 
big_url: The Zoomed Image URL 
alt: Any alt tag you want to add to image 
class: Any CSS classes you might want to add 
width: Width of the magnify glass 
height: Height of the magnify glass 
disable_on_click: on|off Enable/disable the magnify glass on click

Zooom

Zooom is a simple, lightweight jQuery plugin that adds a magnifying glass style zoom functionality to images.

Featured Image Zoom vs Zooom