WDR support on Jetson Nano

Hi all,

We have some doubts about the WDR support on the Jetson boards. As far as we know the Jetson ISP supports the WDR combination on-sensor, it means that the long/short exposures are combined at the sensor side, and the 24-bit or 20-bit result is compressed with a PWL algorithm to 12-bits and sent over CSI-2. When the Jetson captures the frames, the ISP processes them applying the PWL decompression and finally applying a tone mapping algorithm, to achieve one single frame at the output of the ISP.

Is my understanding correct?

Is this the only HDR mode supported?

Does the Jetson Nano supports this functionality?

Thanks for your help in advance.

@CarlosR92

I did not have the time to dig deeper into HDR yet. Did you try it and do not get the results expected?

According to the kernel source, the pixel format should be set to “bayer_wdr_pwl_rggb12” for pwl compression. I have to try that and will do so soon. I am using an IMX390.

PWL support is listed in this document, I do not see a limitation that it should not work on the Nano there:

https://developer.download.nvidia.com/embedded/L4T/r32-2_Release_v1.0/Tegra_Linux_Driver_Package_SW_Features_R32.2.pdf

This document also mentions DOL support, which is a 10 bit HDR format - at least that’s what the pixelformat “bayer_wdr_dol_rggb10” in the l4t kernel suggests.

Pages 5 to 17 of the document are for Jetson Nano, and there are not reference about Nano supporting HDR/WDR. It seems that it was only tested in TX2 and Xavier so likely only those SoC support this feature.

WDR support only for the camera-partner. If you really need WDR sensor it’s better to contact with them.