It's surprising how little code [1] is needed to do this. On the other hand I feel this is quite dependent on the specific camera models and might not work on the RAW data downloaded from my phone. Happy to be corrected. [1] - https://github.com/cchen156/Learning-to-See-in-the-Dark/blob...
But, many DNN concepts (and ML concepts themselves) can be described with a few lines of pseudocode. CNNs, RNNs, etc. can all be described in a few lines.
It's really quite amazing, most of the work goes into first creating the net work from theory, then training and tuning it until you get good results.