The 12 bits image pixel value is negative when shutter time is long

[samliu321]

    I use IMAQ 4.0 and PCIe-1429 and CVI, the image bit depth is 12 bit, the problem is when the shutter time is large enough and the pixel value is large than 4095 then all the pixel value of the image become negative,

   I had observed that someone met same issue before and he had solved it through change the attribute parameter inside MAX, but I don't know the detail,

   Can somebody tell me how to solve this issue and explain in more detail?

   Attached file is the icd file of the camera,

[toto26]

Hello,

The problem can be due to pixels signedness, U16 instead of I16, check your camera manual.

Or it can be due to pixel type. Your icd seems to be 12 bit, so it seems OK. But to be sure, send the command to your camera to force it in 12bit.

Regards