CMSampleBuffer to UIImage in Swift

If you have an AVCaptureVideoDataOutputSampleBufferDelegate, then your captureOutput function will pass a CMSampleBuffer.

Oh yay, another image data type.

If you want to convert that CMSampleBuffer to a UIImage for display, for saving, or whatnot, then you may find your answer here on StackOverflow:

Make an UIImage from a CMSampleBuffer

Alternately, try the code below.

Note that my sample code includes the function imageWithCGImage(orientation:scale:). This is one of several cases in which creating a UIImage from other image type generates a UIImage without an underlying CGImage. Consequently this is only one of several conversion functions I use that returns an optional: UIImage? The function returns either a UIImage with a CGImage, or it returns nil if no CGImage can be created.

import UIKit
import AVFoundation

extension CMSampleBuffer {
    /// https://stackoverflow.com/questions/15726761/make-an-uiimage-from-a-cmsamplebuffer
    func image(orientation: UIImage.Orientation = .up, scale: CGFloat = 1.0) -> UIImage? {
        if let buffer = CMSampleBufferGetImageBuffer(self) {
            let ciImage = CIImage(cvPixelBuffer: buffer)

            return UIImage(ciImage: ciImage, scale: scale, orientation: orientation)
        }

        return nil
    }

    func imageWithCGImage(orientation: UIImage.Orientation = .up, scale: CGFloat = 1.0) -> UIImage? {
        if let buffer = CMSampleBufferGetImageBuffer(self) {
            let ciImage = CIImage(cvPixelBuffer: buffer)

            let context = CIContext(options: nil)

            guard let cg = context.createCGImage(ciImage, from: ciImage.extent) else {
                return nil
            }
            
            return UIImage(cgImage: cg, scale: scale, orientation: orientation)
        }

        return nil
    }
}