Yes, in fact, this entire task sounds like a JavaScript job. From JavaScript, someone can put a local image from a hard drive to appear on the web page. Then the user can crop it, resize it using JavaScript. See Croppic.js. Then inside a canvas object, the JavaScript can get the new resized image pixel by pixel and convert it into any kind of format and upload it to the other side where your Perl script handles it. The JavaScript side of it is done by the Croppic library, so most of the work is already done for you.