How can I fix a display flash during a transition from background to foreground for my iPhone app

For an iPhone app I am working on, I reset the state if the app has been in the background too long. This is a lengthy process (1-2 seconds) so I display a progress indicator during the reset. Unfortunately, this causes the display to flash as the app transitions from the background to the foreground. The flash is caused by the switch from the default image that iOS snaps and the progress indicator that I display. I know I can display the progress indicator as the app initially enters the background state and eliminate the flash. However, I don't want to do this if the app wakes up after a short period of time. I want it t开发者_运维问答o use the default image the iOS snaps. I'm a little stuck on how to overcome this. Does anyone have any suggestions?

Thanks.

pmb