How to improve quality in terms of readability and resolution for images taken using AVCaptureVideoDataOutput()?

We are using AVCaptureVideoDataOutput() as photo output Instance, to capture images. But there was major reduction in the quality of the image as compared to UIImagePickerController which we were using previously. We cannot use AVCapturePhotoOutput or AVCaptureStillImageOutput for capturing the photoOutput as we need to capture  every  single frame of the camera for live filtering  with some filters.

Is there a way we can improve the quality of the images taken using AVCaptureVideoDataOutput(), and make the quality equivalent to the image taken using UIImagePickerController?

How to improve quality in terms of readability and resolution for images taken using AVCaptureVideoDataOutput()?
 
 
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