libraw 0.20.0 returns incorrect D65 multipliers and rgb_cam for ERBG file

I noticed that for the Sony F828 that has an ERBG sensor, the Daylight white balance multipliers returned by 0.20.0 is 2.094020 0.917032 1.222377 0.000000. However, on 0.19.5, the values are 2.094020 0.917032 1.222377 1.203671.

Similarly rgb_cam on 0.20.0 is
1.6726 -0.5983 -0.0743 0
0.0080 1.4036 -0.4116 0
0.0046 -0.4089 1.4043 0

but on 0.19.5 it is
1.6374 -0.2528 -0.0035 -0.3811
0.0672 0.8224 -0.5306 0.6410
-0.0009 -0.3551 1.4153 -0.0593

Is this expected?



Your message subject: libraw

Your message subject: libraw 0.20.0 returns incorrect D65 multipliers and rgb_cam for ERBG file

Could you please clarify why you call 0.20.x data 'incorrect'?

What values do you think are correct and why?

-- Alex Tutubalin

0.20.0 behaviour

This file has four distinct sensors. However, when the multiplier for E is marked as 0, this would indicate that the E component is being discarded. Same with the rgb_cam having 0's for the E component.

I noticed that the cam_xyz is the same as the F828 entry in the adobe_coeff table is the same. This indicates there is a change in how the rgb_cam and hence the Daylight multipliers are derived in the code.

That being said, the 0.19.5 version has a very strong yellow cast on the image but the image definitely looks better in 0.20.0. Please find attached screenshots in the same drive location as above. I assume the 0.20.0 is the expected behaviour.


I also think the new version

I also think the new version is better.

That is why I do not understand why it was called incorrect.

-- Alex Tutubalin

BTW, I strongly suggest to

BTW, I strongly suggest to update to 0.20.2. raw-identify in 0.20.0 may display rgb_cam incorrect.

-- Alex Tutubalin


Apologies for jumping the gun and reporting the issue in 0.20.0 as a bug. I just saw that my tests had failed and assumed a regression. But I agree that 0.20.0 behaviour is better.

I will upgrade to 0.20.2 for the updated raw-identify behaviour.