Five months after Facebook’s (FB) famous $1 billion Instagram purchase, Google (GOOG) is trying to get in on the photo-tweaking action too. The search giant has acquired Nik Software, the 17-year-old company behind photo-editing and filter app Snapseed. Though terms of the deal weren’t disclosed, it’s clearly not Instagram money. That said, Google is pouring cash into its widening battle with Facebook, adding more features to its still-scrappy (but growing) social network Google+. Snapseed is just the latest weapon in Google’s fight to lure Facebook users over to its side.