The background map should be divided into several individual tiles

If the background map is to be displayed in full zoom level (approx. 15x), this image is very large and the calculation takes too long. For this reason it seems to make sense to divide this image into different tiles and to load only those tiles in the editor that are displayed. If necessary, a cache into the file system has to be implement of the scaled images and tiles, because a repeated zoom-in and zoom-out will cause a constant recalculation.