I did not understand exactly what you want
Standard raw processing sequence is (for decoded/linearized data) in dcraw_process is
- black subtraction
- white balance
- demosaic
- data scaling to use full range
- conversion to output color space
Than, on output
- brightness correction
- gamma curve
What stages do you need and what is not?
BTW, besides demosaic, all other steps are trivial and very easy to implement.
I did not understand exactly what you want
Standard raw processing sequence is (for decoded/linearized data) in dcraw_process is
- black subtraction
- white balance
- demosaic
- data scaling to use full range
- conversion to output color space
Than, on output
- brightness correction
- gamma curve
What stages do you need and what is not?
BTW, besides demosaic, all other steps are trivial and very easy to implement.