Is there maybe some kind of tone mapping step applied after histogram1 is calculated? If yes, is it possible to disable that? Is my assumption that histogram1 is of the processed RGB image wrong?
When I turn the light so low that the camera is using maximum exposure time and maximum analogue gain, the histogram shows the image as accordingly darker, but the resulting image appears to be corrected. Is there a way to get the histogram of this corrected image using the ISP?
I also noticed that the digital gain setting doesn’t influence the histogram, but it doesn’t appear to be just that. I also observe the strange behaviour when digital gain is held constant.
Maybe you observed the behavior of the sample plugin instead of NVIDIA Auto Exposure.
Please try if ImageMetaData in 5.2.6 (mentioned in Getting histogram data in 5.2.0 - #16 by VickNV) works for you.
To ensure you have the right expectation, I also want you to know that image quality support is only for specific customers (not via forum). Thanks.