Browse Image and pass it to popup window

I would like to browse an image in my HTML script and then open a popup window in which the browsed image will appear.

Right now he is opening the image in the original script. But how can I pass it to the ShowImage.html popup?

function newwindow(event){
           var pop = window.open("ShowImage.html", "Image","width=200, height=100");
           document.getElementById('output');
           output.src = URL.createObjectURL(event.target.files[0]);
        }

<label>
        Browse File
        <input id="Browse" type="file" style="display: none" checked= true onchange="newwindow(event)">
    </label>

    <img id="output"/>