[iPhone] Improve ProRaw image processing

There was a post earlier today comparing bayer raw vs ProRaw, and some folks (myself included) had some issues with the test. I figured I'd post a comparison where I edited them to have the same look, and do the same pic with my big camera (Canon R7). I manually made sure the exposure and white balance were the same, copied over additional settings(highlight/shadow tonemapping, profile/LUT, etc), and cropped them to match. And I threw in a straight-out-of-the-iPhone-camera HEIC at the end so you can also see that Apple's built in processing has...room for improvement First thing you'll probably notice...they don't look that different! The iPhone camera is really good! It takes fundamentally the same picture the R7 does, just with a few minor artifacts! If you look closely at the iPhone bayer raw, you'll notice it's clipped in some spots where the other two raws are not. There's a noticeable clipped spot on the left wall behind the printer and Magnezone (there's a Hue bar just off screen there) that you don't see in the other two. The colors on the blue LED strip behind the desk are somewhat more clipped and distorted. You see a little bit of that in the ProRaw, but it's not as severe, the ProRaw is closer to the Canon's result (slight note about the LED strip: it's addressable and not on constant color here, it really is somewhat darker and more purple as you move away from the center) The noise level in the bayer raw is also much higher than the other two. The ProRaw has some in-camera denoising and image stacking used to mitigate this. This gets the noise level more like the Canon raw, but at the cost of some "painterly" image artifacts/oversharpening. ProRaws can sometimes also contain noticeable image stitching artifacts, although I can't find any in this particular test Of course, the other two limitations compared to the big camera: can't put whatever lens you want on there, and lower resolution. 48MP ProRaw can fix the resolution somewhat, but the dynamic range is worse than using 12MP binned mode, so it becomes a tradeoff. The R7 will do 32MP at full quality. But hopefully this is helpful to people deciding whether to use ProRaw or not. Personally, I always use it and will never buy an iPhone without it! And for those who struggle to edit ProRaw to their liking, [try not using the profile aka the PGTM edits](https://www.dpreview.com/forums/threads/how-to-get-better-results-from-iphones-proraw-my-experiments-and-info.4814134/)