we now use tiled images for our reader for extra large images.
displaying tiled images is a technique that is most commonly used in maps apps so that it can display a large map image at multiple zoom levels and we're the first one on appstore to bring this to a manga reader. actually, we go even further technical-wise by tiling images on-the-fly whereas maps would often have their map image pre-tiled on their server.
the benefits are:
first, we've seen the memory usage dropping up to 10x in some situations, preventing many of the out-of-memory crashes when viewing those particular mangas with long-long-long images.
second, the page loading performance also has improved up to 5-6x for particularly large images.
Competing apps tried to solve this same problem by down-scaling memory-intensive images to the point that texts become blurry.
Some other apps simply crashed on those same pages during our testing.