jpg/png images on my app are too slow to download

[benlester]

I currently have a live app which downloads from a database. This includes jpg or png images which are typically up to 20KB. The images currently take too long to download which delays the user experience. Does anyone have advice on alternative image types which can be used on iphone apps?

[Orijnal]

I had the same issue... you don't need to look for an alternative to .jpg/.png files, you need to look into asynchronous image loading and image caching.

For the asynchronous image loading, look at this example:
URLCache project in the iOS Reference Library

Also, there's a nice tutorial on image caching, here in the forums:
Image Caching Tutorial

No worries - your app will perform significantly better once you've implemented a combination of these techniques. Good luck!

[smithdale87]

PNG is the best for the iphone. Consider using downsizing your images. If that's not possible, consider how you are downloading them. Are you doing it synchronously or async? Are you saving the downloaded images to disk so they only need to be downloaded once, or are you downloading them each time the app is launched?