Resize image proportionally javascript

function reSizeImageProportionally (imgObj,imgContainerId) {
    var container = $(imgContainerId);
   
    var imgRatio = imgObj.height / imgObj.width;
    var containerRatio = container.height() / container.width();
    var ratio = containerRatio / imgRatio;
   
    imgObj.style.height = ratio * container.height()+ "px";
    imgObj.style.width = ratio * container.width()+ "px";

    container.append(imgObj);

    return container;
};
  
Usage:
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var img= new Image();
img.src="http://localhost/Custom/USSI/Layers/Ticket/Legend.jpeg";
var result=reSizeImageProportionally(img,'.tl_tab_legend_panel_div'); //  Div id  or Class Name