We've developed a Photo Editing extension to edit user's photos. But the photos which user take have large high-resolution. When editing them in extension, it will cost about 100-200MB memory and extension get crashed. But we can't reduce user photo's resolution, how to apply more memory in Photo Editing extension?
I have the same problem. I'm writing an extension to complement my photo editing app. My filter pipeline is relatively complex; it uses a maximum of 6 image-sized textures at a time. However, in the main app I can even process the full camera image size of 8 MP (iPhone 5s) without running into memory issues.
In the extension, I use the display-sized image given by the framework for displaying the preview of the filter to the user, which works perfectly fine. But when I try to apply my filter to the original image as soon as the user taps Done, the extension crashes with the error message Terminated due to Memory Error (in Xcode). I even refactored my shaders and texture management code to only use half (!) of the previous amount of memory, but the extension keeps crashing.
I know Apples guide explicitly mentions lower memory limits:
Memory limits for running app extensions are significantly lower than the memory limits imposed on a foreground app. On both platforms, the system may aggressively terminate extensions because users want to return to their main goal in the host app. Some extensions may have lower memory limits than others: For example, widgets must be especially efficient because users are likely to have several widgets open at the same time. [...]
Keep in mind that the GPU is a shared resource in the system, and so app extensions don’t get top priority. For example, a Today widget that runs a graphics-intensive game may give users a bad experience on both platforms and is likely to be terminated because of memory pressures.
But I don't see how complex photo editing apps are supposed to work with that. The current memory constraints are clearly too high. The only option I see right now is to reduce the image size when saving results and prompt the user about it and tell him/her to use the main app for hi-res export ... which totally misses the point of the extension. I hope Apple will raise the limits before the final release of iOS 8.
I just updated to the iOS 8 GM release and the GM release of Xcode 6. Now everything works perfectly fine! I am able to process 8 MP images without any memory warning now.