init(cgImage:pixelsWide:pixelsHigh:pixelFormatType:options:)

Construct image feature value from CGImage (orientation is assumed to be kCGImagePropertyOrientationUp)

convenience init(cgImage: CGImage, pixelsWide: Int, pixelsHigh: Int, pixelFormatType: OSType, options: [MLFeatureValue.ImageOption : Any]? = nil) throws