Sustainability of Digital Formats: Planning for Library of Congress Collections

Apple ProRAW is a still image format introduced in 2020 with the release of Apple's iPhone 12 series and iOS 16.0.3. Apple ProRAW files are raw Adobe Digital Negative (DNG), Version 1.6 files with specific settings applied and store additional metadata. ProRAW files are built from multiple image frames.

Apple, Inc. announced and described the format on Apple Support Communities on December 14, 2020 for use on iPhone 12 Pro and later Pro models with iOS 14.3 or later. Apple, Inc. describes the format as a combination of the information of a standard RAW format along with iPhone image processing. On iPhone 14 Pro, Apple ProRAW images can be captured at two resolutions: 12 megapixels (approximately 25MB in size) or 48 megapixels (approximately 75MB).

Like DNG 1.6, ProRAW files have the DNG file extension. When editing and sharing the photo using the iOS Photos app, the photo will be a JPEG and have the JPG file extension. At and around the time of release, Apple ProRAW is not enabled on iOS by default, but it can be configured in the phone settings.

ProRAW incorporates the following DNG 1.6 features:

• Demosaiced: ProRAW stores results of computational photography pixel values after the demosaiced step, inside the file. Since ProRAW has already done the demosaicing step, it is technically not a RAW file.
• Profile Gain Table Map (link via Internet Archive): Apple worked with Adobe to introduce this new tag. As described by Lux, "this data gives your editor everything it needs to know to tone map your photo image and end up with results identical to the first party camera. Because it's separate data, you can turn down its strength, or turn it off completely."
• "Deep Fusion": ProRAW files are processed using machine learning that "do pixel-by-pixel processing of photos, optimizing for texture, details and noise in every part of the photo."
• " Semantic Masks" (link via Internet Archive): This is used for image segmentation, allowing masks (images) to be stored in the file. Files can store multiple masks. These masks can be used on faces or create background blur.

For more differences in DNG 1.6 compared to previous versions, see Adobe Digital Negative (DNG), Version 1.6.

Apple, Inc. announced and described the format at "About Apple ProRAW" on Apple Support Communities on December 14, 2020.

Apple Developer Documentation: "Capturing Photos in RAW and Apple ProRAW Formats".

See Adobe Digital Negative (DNG), Version 1.6.