Hello Serge, I use this work around for the Mobile edition of Memento.
Don't take the picture from within the Memento app. There have been changes to Android which saves the pictures in a hidden folder. Take it from your device's camera so the picture is saved to your Gallery. Edit it as you wish.
Then go to Picture folder in Memento and move your picture into this folder.
Open Memento, open your image field, navigate to Memento Picture folder on your device and select.
Please note:. You can still take pictures vin the Memento application, just can't locate the folder they are saved in. At least I haven't been able to find it.
Beth