Why are my AVCapturePhotoOutput file outputs so large?

Question

I'm creating a camera app and everything is working well but the file-size of the photos that is being uploaded to Firebase are too big. They are in the 3MB category and I would like them to be in the ±600KB category.

I have set the AVCapturePhotoSettings.isHighResolutionPhotoEnabled to false but that does not appear to do anything and AVCapturePhotoOutput.quality.balanced only works for iOS13+ which is not going to work in my case.

Here is the delegate function that sends the image to my imageArray

extension NewPostFromPhoto: AVCapturePhotoCaptureDelegate {
    func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
    if let error = error {
        debugPrint (error)
    } else {

        photoData = photo.fileDataRepresentation()
        UIImageWriteToSavedPhotosAlbum(UIImage(data: photoData!)!, nil, nil, nil)
        self.imageArray.insert((UIImage(data: photoData!)?.fixOrientation())!, at:0)
        self.recentMediaCollection.reloadData()
    }
}

}

and here is my takePhoto() method:

func takeNewPhoto () {

    let settings = AVCapturePhotoSettings ()
    settings.isHighResolutionPhotoEnabled = false
    photoOutput?.capturePhoto(with: settings, delegate: self)
}

Ruben Nahatakyan · Accepted Answer · 2019-12-12T06:46:20.057

1

Using your code I got pngData about 20 MB. But when we take jpegData(), we got about 2.2 MB.

image.jpegData(compressionQuality: 0.8)

Here full code from delegate

func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
    guard let imageData = photo.cgImageRepresentation() else {
        self.captureFailed(error: error?.localizedDescription ?? "Can't take image from output")
        return
    }
    let cgimage = imageData.takeUnretainedValue()
    let orientation: UIImage.Orientation = captureDevice?.position == .front ? .leftMirrored : .right
    let image = UIImage(cgImage: cgimage, scale: 1, orientation: orientation)
    let data = image?.jpegData(compressionQuality: 0.8)
}

Hope its help

edited Dec 12 '19 at 06:46

answered Dec 12 '19 at 06:29

Ruben Nahatakyan

372
3
13

Thank you, Where does this go in the delegate? – Brewski Dec 12 '19 at 06:41
That sort of worked thank you, I had to update your solution a bit to work with my code: let image = UIImage(data: photoData!) and let smallerImage = UIImageJPEGRepresentation(image!, 0.8) - jpegData is deprecated. It didn't appear to make the image file-size a lot small but it does load faster and shaved about 20% off the file-size. – Brewski Dec 12 '19 at 07:08
I am using swift 5 and in here jpegData is not deprecated. But when i try to use `UIImageJPEGRepresentation` XCode was show error `'UIImageJPEGRepresentation' has been replaced by instance method 'UIImage.jpegData(compressionQuality:)'` Which version of swift you use? – Ruben Nahatakyan Dec 12 '19 at 07:24
strange, with me it says the opposite: "UIImage.jpegData(compressionQuality:) has been replaced by UIImageJPEGRepresentation" for now I'm going to close my eyes and pretend it is all fine :D – Brewski Dec 12 '19 at 07:27

Why are my AVCapturePhotoOutput file outputs so large?

1 Answers1