It happens often that on the homescreen there are many images representing the content of the subpages. The images can not be the same as the ones in the subpages, since the homepage would take too long to load, especially for users with poor internet connection. Therefore for every single image, a thumbnail must be created. When wanting to create a thumbnail, the easiest possiblity is to open the image in a graphics editor and change the size manually. Nevertheless, when creating tens or hundred of thumbnails, this is not a solution.