Using the filters in iOS 7's Camera app is a fun way to spruce a photo. For whatever reason, iOS 7 doesn't deselect a filter after you exit the Camera app, leading you to inadvertently filter some photos.
For example, if you take a pic using any of the available filters, exit the app, and then awhile later quickly launch the camera to catch an impromptu photo, the filter is still selected and thus applied to your photo.
Luckily, there's a quick and easy way built into iOS 7 that allows you to change or remove filters from a photo.
Putting filters on a photo is simple as pie. But taking one off can be a hassle, meaning you should have saved the original before changing it. iOS 7 has made it now, as simple as pie to change or remove filters from a photo.