I am creating a simple android app to view a comic book. The pages are large(0.5-1 mb each), high quality .png's and I am loading them into a webview to make use of the built in zoom controls. So far I only have 17 files and the APK size is already about 16 mb. I'm looking to add over 200 files in future updates. I can't really reduce the quality too much because there is small text that must be zoomed-in on to read. Any suggestions? A similar question was posted here: How to reduce App (.apk) Size, but I don't want to lose the quality of the images. I'm not sure if it's appropriate to link to here, but you can have a look at my app by searching for Tracer (by Detour Mobile) on the android market if it helps at all. Thanks in advance.
You could compress them without using lossy compression- e.g. zipping/rarring them, but I don't believe this would gain you much more than a few kilobytes here and there. Otherwise, try using a more compact format than PNG, such as JPEG (you won't lose too much quality.) By the way, all of this was suggested in the referenced post.
If you do decide to scale down the images' size somewhat, be sure to use a method like bicubic sharper- it tends to look better than others when reducing image size.
Another option would be to download the images for the comic that is being read on-the-fly with pre-fetching so reading would not be interrupted as much.