You know the scenario -- you try to take a creative photo by applying a filter and then hate how it turns out. You decide to snap another shot, but the moment is gone, and you are left with an ugly photo of a beautiful scene. If you used iOS 7 to snap your photo, then you are fortunate as you may be able to remove that offending filter. As originally described by MacObserver, just follow these few directions below.
If you are on an iPhone 4s, iPhone 5, iPhone 5s or an iPod touch (fifth gen), then you can easily undo the camera filter in a few short steps. Just open the image in the Photos app, and click on the "Edit" button in the bottom-middle of the toolbar. When you are in editing mode as shown above, you'll notice the tri-circle icon for the filters. Tap on the filters icon and then scroll to the left to select "None." Hit "Apply" in the upper-right-hand corner and, voila! The filter will be removed. You can also change the filter to another one as I did in the image below.