cgImage
The CoreGraphics image object this image was created from, if applicable.
Declaration
var cgImage: CGImage? { get }Discussion
If this image was created using the init(cgImage:) or init(contentsOf:) initializer, this property’s value is the CGImage object that provides the image’s underlying image data. Otherwise, this property’s value is nil—in this case you can obtain a CoreGraphics image by rendering the image with the CIContext createCGImage(_:from:) method.