Software rasterized image viewer. This particular image has 272 megapixels (14108 x 19347) and ~1GB of raw size. A mipmap of the image is created ahead of time and saved as 1024x1024 tiles. The viewer runs in about 50MB of RAM, with 16 cached tiles of 1024x1024 pixels, loading tiles from the appropriate mipmap level on demand. Some prediction is still needed to avoid flickering.