WIA Scanner Issue when hosted in server

If you're trying to scan at the client side, the browsers don’t have direct access to the devices attached to the PC. This is done to protect the client from malicious attacks from websites and is a necessary feature in all browsers. The only way to have something access the devices located on the clients machine is to have a client-side service that runs on the machine that will connect to the device and then the browser connects to the service.

This is the idea behind the LEADTOOLS web scanning demo that you can find here:
https://www.leadtools.com/sdk/twain/html5-web-scanning

Also, you can see this feature in action using the following online demo:
http://demo.leadtools.com/javascript/ScanningDemo/