I am a graduate student working with the NVIDIA Jetson TX1 to collect some images for our HDR camera. I wanted to know if there is any way to give an ISO setting in Gstreamer while acquiring images.

We have a problem with a purple color cast on our low light images and based on my searches on the internet one of the reason might be the auto ISO setting.

I was wondering if there is a way to set the ISO then I can get rid of the purple color cast / purple hue on my low light images.

Thank you

hello bharat91,

  1. may I know which JetPack release, and which HDR sensor you’re working with?
  2. suggest you launching camera with argus_camera application, which have user-interface for sensor settings configuration.
    please refer to Camera Software Development Solution for details.
  3. you could get the sources of L4T Multimedia API through Jetson Download Center, you’ll need to compile these sources on the target for demonstration.
  4. please access L4T Multimedia API Reference for multimedia documentation. thanks

Hi Jerry,

We are using the image sensor IMX290 from leopard imaging. We are building our own custom HDR rig using those sensors. The JetPack version we used is 4.2 . Also we used jetpack only for loading the ISO. The rest of the drivers and stuff we followed the instructions from leopard imaging.

Also we were not able to find any ISO setting in the Argus GUI application. Is there something I am missing here? Here is the image of the Argus GUI which we use:

I will look into what you have said and hopefully find some solution. I have looked through some of the Gstreamer documentation but could not find anything on ISO settings though.

Let me know if you have more thoughts on the purple color cast or the ISO settings.

Thank you

hello bharat91,

  1. The effective ISO is the sensor’s gain multiplied by its nominal ISO sensitivity, hence you could adjust the gain settings to reflect the ISO settings.
    you may refer to documentation, [ISO 12232:2006] for the calculation of the ISO settings.
    in addition, you might also check about the difference between gain and ISO from the aspect of consumer camera devices.

  2. Let me know if you have more thoughts on the purple color cast or the ISO settings.
    suggest you share the abnormal capture results for reference.
    however, ISO settings should only affect the light sensitivity. color cast should be caused by post-processing.
    may I know your environment settings to capture color cast images?
    you should also contact with Leopard Imaging for further investigation.

  1. The way our HDR camera works in to have low gain settings so we are constrained to using a specific gain value based on our theoretical calculations.

  2. Here is the image with the purple cast: — the exposure for this image was 0.002 secs
    This picture was taken indoors in our lab. What kind of environment settings are you looking for?
    It does not make me believe its caused by post-processing because we don’t have this problem when we take an image in high exposure settings. Happens only in low exposure settings. But I might be wrong and we might be messing up our usage in the drivers or something.

hello bharat91,

indeed, your issue don’t seems caused by post-processing after checking your capture result.
according to your comments,

“using a specific gain value based on our theoretical calculations.”
could you please keep narrow down the issue,
couple of suggestion as below.

  1. please hard-core the gain values for checking.
  2. please exclude sensor digital gain for checking.

may I know your commands to launch camera for testing?
please also share the parameter settings if you’re working with argus_camera.