I am working on a computational photography research project involving multi-exposure HDR reconstruction using Bayer RAW and Apple ProRAW captures. I would like to clarify the radiometric interpretation of Apple ProRAW and the availability of Bayer RAW capture through AVFoundation.
My questions are:
On current iPhone Pro devices, is it possible for third-party apps to capture and export true Bayer-pattern RAW DNG files through AVFoundation, rather than Apple ProRAW linear DNG files? If so, which availableRawPhotoPixelFormatTypes correspond to Bayer RAW, and what device or format restrictions apply? Apple ProRAW appears to be demosaiced and computationally processed, and may include multi-frame fusion. Is the decoded ProRAW image intended to be radiometrically linear and scene-referred? For a bracketed ProRAW sequence captured with fixed ISO, white balance, lens, and focus, but different exposure times, can one assume that the decoded linear pixel values Y_i(p) satisfy an exposure-proportional model in non-saturated regions, such as Y_i(p) ≈ t_i R(p), across brackets?
This question is about radiometric consistency for algorithmic use, not about visual editing or tone mapping.
Thank you for your help.