mapSizer.js A script that resizes an image and page to specific dimensions, centers the image on the page and puts it on the map layer.

mapSizer.js

//usage - !mapSizer imageWidthInPixels imageHeightInPixels
on("ready",function(){   
    on("chat:message",function(msg){
        if(msg.type=="api" && msg.content.indexOf("!mapSizer")==0){
            var args = msg.content.split(" ");
            var mapWidth = Number(args[1]);
            var mapHeight = Number(args[2]);
            var selected = msg.selected;
            if(selected===undefined){
                sendChat("API","Please select a graphic");
                return;
            }
            if(isNaN(mapWidth)||isNaN(mapHeight)){
                sendChat("API","Please enter a valid number for width & height");
                return;
            }
            var map = getObj("graphic",selected[0]._id);
            var page = getObj("page",map.get("pageid"));
            
            page.set({
                width:mapWidth/70,
                height:mapHeight/70
            });
            
            map.set({
                width:mapWidth,
                height:mapHeight,
                top:mapHeight/2,
                left:mapWidth/2,
                layer:"map"
            });
        }
    });
});

This is great. I adjusted using your YT updates. I new to this coding thing so going to try to update that to any sizer instead of just maps.