Clear memory used by UIImage — UIImageView.image = nil doesn't do it

Question

I have created an UIScrollView that contains photos, like in the Photos app.

Photos are downloaded. Images are set through:

imageView.image = [UIImage imageWithData:downloadedImageData];

To save memory, when the user goes far from a photo, I set

imageView.image = nil;

This doesn't clear the memory, though. "Memory Leaks" from Instruments doesn't show any memory leaks.

Can anyone recommend me how to optimize the memory used by images?

Answer 1

[UIImage imageWithData:] is autoreleased object, so it will be freed somewhere in run loop. To release it for sure, use alloc/init constructor.