Color Incorrect with CSI Camera on Jetson

Issue Overview

Users are experiencing color issues when using a CSI camera with the Nvidia Jetson platform. The captured images appear to have an incorrect color balance, with a strong green tint. This problem occurs when using both GStreamer pipelines and OpenCV applications to capture and process images from the camera. The issue persists despite attempts to modify the pixel format and color space settings.

Possible Causes

1. Incorrect camera driver configuration: The camera driver might not be properly configured to handle the specific color format of the sensor.

2. Mismatched color space conversion: The pipeline or application might be using an incorrect color space conversion method for the camera’s output.

3. Improper ISP (Image Signal Processor) settings: The ISP configuration might not be optimized for the specific camera sensor being used.

4. Bayer pattern mismatch: The assumed Bayer pattern in the processing pipeline might not match the actual pattern output by the camera.

5. Incorrect pixel format interpretation: The system might be misinterpreting the raw pixel data from the camera sensor.

Troubleshooting Steps, Solutions & Fixes

1. Verify camera specifications:

   • Use the v4l2-ctl command to check the camera’s capabilities and current settings:

     v4l2-ctl -d /dev/video0 --all
     

   • Confirm that the pixel format and color space settings match the camera’s specifications.

2. Adjust GStreamer pipeline:

   • Experiment with different pixel formats in the GStreamer pipeline. For example:

     gst-launch-1.0 nvarguscamerasrc ! 'video/x-raw(memory:NVMM),width=1920, height=1080, framerate=30/1, format=(string)NV12' ! nvvidconv ! 'video/x-raw,format=(string)BGRx' ! videoconvert ! 'video/x-raw,format=(string)BGR' ! nvjpegenc ! filesink location=test.jpg
     

3. Modify OpenCV capture settings:

   • Update the OpenCV capture pipeline to explicitly set the color format:

     nvarguscamerasrc ! video/x-raw(memory:NVMM), width=(int)1920, height=(int)1080, format=(string)NV12, framerate=(fraction)30/1 ! nvvidconv ! video/x-raw, format=(string)BGRx ! videoconvert ! video/x-raw, format=(string)BGR ! appsink
     

4. Check ISP configuration:

   • Review the Image Signal Processor (ISP) settings for your specific camera model.
   • Consult the camera manufacturer’s documentation for recommended ISP configurations.

5. Update camera drivers:

   • Ensure you have the latest camera drivers installed for your Jetson platform.
   • Check the Nvidia Developer website for any available updates specific to your camera model.

6. Adjust camera controls:

   • Use v4l2-ctl to modify camera controls that might affect color reproduction:

     v4l2-ctl -d /dev/video0 --set-ctrl=exposure=<value>
     v4l2-ctl -d /dev/video0 --set-ctrl=gain=<value>
     

7. Implement custom color correction:

   • If the issue persists, consider implementing a custom color correction matrix in your application to compensate for the color shift.

8. Contact camera manufacturer:

   • As a last resort, reach out to the camera manufacturer for support.
   • Request the ISP definition file for your specific camera model.

9. Apply manufacturer-provided ISP definition:

   • Once you receive the ISP definition file from the camera manufacturer, apply it to your Jetson system.
   • Follow the manufacturer’s instructions for installing and configuring the ISP definition file.

10. Verify color correction:

    • After applying the ISP definition file, capture new images and verify that the color issues have been resolved.
    • If problems persist, consult with the camera manufacturer for further assistance.

By following these steps and applying the manufacturer-provided ISP definition file, users should be able to resolve the color inaccuracy issues with their CSI cameras on the Jetson platform.