JSFiddle - React, Tailwind, and code Playground

HTML

<img src="" width="150" height="100" />

JavaScript

function imageSize(img){
      var theImage = new Image();
      theImage.src = img.attr('src');
      var imgwidth = $(img).width();
      var imgheight = $(img).height();
    
      alert(imgwidth);
      alert(imgheight);
    }

$('img').each(function(){
    var imgsrc = jQuery(this);
    imageSize(imgsrc);
});