Improve raw noise model for N5.
Replace the current raw noise model, calibrated using Android's
dng_noise_model.py script, with an improved noise model, using an
updated version of that script.
The new raw noise model has a different parameterization in terms
of ISO:
- The formula for 'S' scales with ISO. While shot noise should
be zero for a completely dark signal, we still include an offset
here to help compensate for black level variations with ISO.
- The new formula for 'O' scales with ISO^2, not ISO. This form is
required because 'O' corresponds to the *variance* due to read
noise. The new formula also treats analog and digital gain
separately. While pre-ADC read noise is affected by both types
of gain, post-ADC read noise is affected *only* by digital gain.
Bug: 16273313
Change-Id: If7d1e48138230a487a5b270e5686c699e80ff419
1 file changed
