COMP_GREEN1
COMPGAIN(COMP_GREEN1, currentexp, startexp);
sd->params.exposure.green1Comp = COMP_GREEN1;
startexp += EXP_FROM_COMP(COMP_GREEN1,
sd->params.exposure.green1Comp = COMP_GREEN1;
#define COMP_GREEN2 COMP_GREEN1
params->exposure.green1Comp = COMP_GREEN1;