MT9J001 only seeing 8 bit data with 12 bit config and python demo

I am using the MT9J001 camera board with UC391 Rev.E USB2.0 board. When I run the windows python demo ArduCam_Py_Demo.py with config file MT9J001_MONO_12b_3664x2748.cfg, I am only seeing 8 bit data. Inside the readImage_thread(), the image data is stored inside variable ‘data’ with: rtn_val,data,rtn_cfg = ArducamSDK.Py_ArduCam_readImage(handle)

When I print out data or the np.max(data), I only see 255 at most even with a saturated image? What else do I need to get 12 bit working on this camera?!

Thanks

I think you need to confirm the subsequent conversion process or the size of the entire data.
Because no matter how many bits the camera outputs, the data format is uint8_t but the total size will change.
For example, the size of 640x480 16bit is 640x480x2.