Size all selected images to similar visual gravity

resize-images.js

/*********
*
*  resize logos in custom galleries.
*
*/
window.addEventListener("load", function() {
	var images = document.querySelectorAll(".custom-gallery img");

	var adjustImageWidth = function (image) {
		var widthBase   = 250;
		var scaleFactor = 0.525;
		var imageRatio  = image.naturalWidth / image.naturalHeight;

		image.width = Math.pow(imageRatio, scaleFactor) * widthBase;
	}

	images.forEach(adjustImageWidth);

}, false);