How does color depth and/or compression level of images affect UI performance?

Question

To what extend do color depth and compression level of the original jpg and/or png images used as drawables have an effect on the app's UI performance, given the fact that all images are converted to bitmaps internally anyway. Especially considering i.e. images in list views for example.

Same question goes for png vs. xml shapes as drawables.

Edit: I found a similar question which addresses memory usage, but my focus is more on UI performance (i.e. scrolling long list views, etc.). http://stackoverflow.com/questions/2602282/android-is-decreasing-size-of-png-files-have-some-effect-to-resulted-bitmap-in

Larger images probably take longer for decompressing, but when they're cached properly (and i.e. asynchronous lazy loading), after initial loading, it shouldn't matter anymore.

Answer 1

If the images are indeed all are converted to bitmaps internally anyway, then I think you're right, the compression level of the original file makes no difference once the image is loaded.

Color depth of the image, on the other hand, would still be a preserved difference, right? I.e. image files of different color depth on disk can be loaded to in-memory images of different color depth. So I would expect "deeper" images to have an adverse effect on performance eventually.

But as always, you never know for sure about performance till you run tests.