Add new comment

This change will break

This change will break accurate per-channel black level calculation for (affected) Canon cameras.
It may be not your case (if your code uses own blacks calculated from raw data), but will affect other users and may result in excessive banding. So, no plans to implement this #ifdef in main LibRaw source code.

Taking into account the fact that margins may change with firmware update, it is better to change your application to handle this feature accurately.

-- Alex Tutubalin