写真に対してVision.Frameworkで顔認識させる時の注意点

extension UIImage {

    func fixedOrientation() -> UIImage? {
        guard let cgImage = base.cgImage,
            let colorSpace = cgImage.colorSpace,
            let ctx = CGContext(data: nil,
                                width: Int(base.size.height), height: Int(base.size.width),
                                bitsPerComponent: cgImage.bitsPerComponent,
                                bytesPerRow: 0, space: colorSpace,
                                bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue) else { return nil }

        var transform: CGAffineTransform = CGAffineTransform.identity

        switch UIDevice.current.orientation {
        case .landscapeLeft:
            transform = transform.translatedBy(x: base.size.height, y: base.size.width)
            transform = transform.rotated(by: CGFloat.pi)
        default:
            break
        }

        ctx.concatenate(transform)
        ctx.draw(cgImage, in: CGRect(x: 0, y: 0, width: base.size.height, height: base.size.width))

        if let newCGImage = ctx.makeImage() {
            return UIImage.init(cgImage: newCGImage, scale: 1, orientation: .up)
        } else {
            return nil
        }
    }
}