Implicit conversion from enumeration type 'enum CGImageAlphaInfo' to different enumeration type 'CGBitmapinfo' (aka) 'enum CGBitmapInfo')

The constants for specifying the alpha channel information are declared with the CGImageAlphaInfo type but can be passed to this parameter safely.

Just use a cast to suppress the warning:

CGBitmapInfo bitmapInfo =(CGBitmapInfo) kBitmapInfo;