Load all resources before loading Activity?

Load all resources before loading Activity?

I have an activity which has to grab heavy images, resize them and loads
into GridView. Since all this process of fetching, resizing is time
consuming, when I try to load this screen from another ACtivity, I get a
delay.
How can I first load the content of this "grid activity" and open it only
after all images have been loaded?
Using startActivityForResult? If this is a solution, how can I detect that
all images have been loaded since GridView load images on scroll.