It can be easily done using html2canvas, try out the following,
try adding the div inside a html modal and call the model id using a jquery function. In the function you can specify the size (height, width) of the image to be displayed. Using modal is an easy way to capture a html div into an image in a button onclick.
for example have a look at the code sample,
`
<!-- Modal content-->
<div class="modal-content">
<div class="modal-header">
<div class="modal-body">
<p>Some text in the modal.</p>
`
paste the div, which you want to be displayed, inside the model. Hope it will help.