Max headroom in pixels
What's important to note, at this point, is that except for the outliers where a pixel's values are very different on both sides (massively out-of-focus areas?), most of your values here should be very small positive or negative numbers, with many pixel values being nearly all zeroes or ones. Encode a second image as the difference between the left + right images.
#MAX HEADROOM IN PIXELS FULL#
Encode one full image as the sum of the left + right images.It seems to me that they should have combined sum-difference encoding, sign-magnitude encoding, and run-length encoding, as follows: The result is that the auxiliary image takes a lot more space than it actually needs to. What were they thinking? They basically encoded (I think) the sum of the two images as the first image, plus one of the two images as the second (that's your one-stop difference). Compare two shots in Fine mode - taking the main frame from Dual Pixel raw (the left part of the picture below - the dual pixel raw and its histogram) and the "regular" Fine raw (the right part of the picture below - the "regular" raw and its histogram). Here is how you can check that the main subframe of the dual-pixel raw is the same as a regular raw. This confirms that the difference between the main and auxiliary subframes is nearly 2x, or 1 stop, and that the auxiliary subframe can be used for highlight recovery (again, an additional 1 stop of highlights is preserved in the auxiliary subframe while being clipped in the main subframe), effectively providing one more stop of headroom in the highlights and the dual-pixel raw file for this camera contains 15 bits of raw data, if you consider main and auxiliary subframes together. Channel averages for the selection on the main subframe vs.