Minimal image preload

preload.js

/*
 * Preload de imagens
 *
 * @param {array} imgs - Array com o path das imagens
 * @example preload(['img/foto1.jpg', 'img/foto2.jpg']);
 */

function preload( imgs, fn ) {

    var len = imgs.length,
        totalLoaded = 0;

    function loadImage() {

        var img = new Image();

        function noop() {}

        img.error = function() {
            preload();
        };
    
        img.onload = function() {

            totalLoaded++;

            try {
                delete img.onload; // liberando memoria
            } catch( err ) {
                img.onload = noop; // IE7
            }

            if ( totalLoaded === len ) {
                fn();
            }

        };

        img.src = imgs[ i ];

    }
    
    for ( var i in imgs ) {

        loadImage( i );

    }

}


preload(['http://www.site.com/img1.jpg', 'http://www.site.com/img1.jpg'], function() { 
  console.log('carregou'); 
});