pngData()
Returns a data object that contains the specified image in PNG format.
Declaration
func pngData() -> Data?Return Value
A data object containing the PNG data, or nil if there was a problem generating the data. This function may return nil if the image has no data or if the underlying CGImageRef contains data in an unsupported bitmap format.
Discussion
If the image object’s underlying image data has been purged, calling this function forces that data to be reloaded into memory.