A key for a CIVector object that specifies the center of the area, as x and y- coordinates, to be filtered.
Available in OS X v10.5 and later. Not available in iOS.
Availables Keys for input parameters to filters in iOS.
- kCIOutputImageKey;
- kCIInputBackgroundImageKey;
- kCIInputImageKey;
- kCIInputVersionKey;
So we need to accept the compiler's complaint