These coefficients are stored in imgdata.color.cam_mul[4]
Depending of camera used, 4th coefficient ('second green') may be
- zero (use cam_mul[2] for second green or assume two greens in 2x2 matrix are same)
- same as cam_mul[2] (OK)
- different from cam_mul[2] (really 4 color camera, like old Olympus E-5xx series or Sony F-828, or CMYG camera like Nikon E5700 or Canon G1)
For 4-color cameras you need to use demosaic method suited for this case (4 color in 2x2 matrix, not two similar G and one R and one B).
These coefficients are stored in imgdata.color.cam_mul[4]
Depending of camera used, 4th coefficient ('second green') may be
- zero (use cam_mul[2] for second green or assume two greens in 2x2 matrix are same)
- same as cam_mul[2] (OK)
- different from cam_mul[2] (really 4 color camera, like old Olympus E-5xx series or Sony F-828, or CMYG camera like Nikon E5700 or Canon G1)
For 4-color cameras you need to use demosaic method suited for this case (4 color in 2x2 matrix, not two similar G and one R and one B).