Yesterday I tried to delete one photo from the Android application Gallery, found it's from the auto backup, cannot delete, there is no option to do so, I went to the auto backup website, found that photo had been already deleted before, then how come this photo is still there in the gallery? this made me confused. two steps to delete this photo in the gallery,
1, go to the auto backup google account to disable the auto synchronize. go to Settings->account->Google.
2, clear the data and cache in the Gallery settings, go to Settings->More->Application manager->Gallery. after clearing, the photo in the cache is deleted.