$(window).on('resize', function () {

  if ($('.ngx-gallery-active').length) {
    RedimensionarImagenPrincipal();
  }
});

$(document).on('DOMNodeInserted', '.ngx-gallery-active', function () {
  RedimensionarImagenPrincipal();
});

function RedimensionarImagenPrincipal() {
  var image_url = $('.ngx-gallery-active').css('background-image');

  if (image_url) {

    image_url = image_url.match(/^url\("?(.+?)"?\)$/);


    if (image_url[1]) {
      image_url = image_url[1];
      image = new Image();

      image.src = image_url;
      var mainWidth = $('ngx-gallery').width();

      // var newHeight = (parseFloat(mainWidth) * parseFloat(image.height) / parseFloat(image.width));// + 150;
      // var newHeight = parseFloat(image.height); // + 150;
      // if (newHeight > 600) newHeight = 600;

      var newHeight = (mainWidth / parseFloat(image.width) * parseFloat(image.height));

      if (newHeight > image.height) {
        newHeight = image.height;
      }

      if ($('.ngx-gallery-thumbnails').length) {
        newHeight += 150;
      }

      $('ngx-gallery').height(newHeight);

      if ( $('ngx-gallery').width() > image.width) {
        $('.ngx-gallery-image.ngx-gallery-active').width(image.width);
      }
    }
  } else {
    $('ngx-gallery').height(0);
  }
}