Pixel Oversaturation Issue with IMX477 Camera on NVIDIA Jetson Orin Nano

Issue Overview

Users of the NVIDIA Jetson Orin Nano development board, specifically running Jetpack version 5.1.2, are experiencing pixel oversaturation problems when using the IMX477 camera module. The issue manifests in two main scenarios:

1. During daytime: The area around the sun becomes saturated.
2. At night: Car headlights and streetlights appear oversaturated.

The camera is operating in linear mode, suggesting that the problem may be related to the camera’s inability to handle high dynamic range scenes effectively. This issue significantly impacts the video quality and could potentially affect the performance of computer vision applications relying on this camera input.

Possible Causes

Several factors could contribute to the pixel oversaturation problem:

1. Limited Dynamic Range: The IMX477 sensor might have insufficient dynamic range to capture both bright and dark areas in high-contrast scenes.

2. Incorrect Exposure Settings: The camera’s automatic exposure control may not be optimized for high-contrast scenarios.

3. ISP Configuration: The Image Signal Processor (ISP) settings might not be properly tuned for the specific lighting conditions.

4. Driver Issues: There could be bugs or limitations in the camera driver that prevent proper handling of high-contrast scenes.

5. Firmware Limitations: The camera module’s firmware might lack advanced features for managing challenging lighting conditions.

6. Software Processing: Post-processing algorithms in the Jetpack software stack might not be effectively managing the raw sensor data.

Troubleshooting Steps, Solutions & Fixes

To address the pixel oversaturation issue with the IMX477 camera on the NVIDIA Jetson Orin Nano, consider the following approaches:

1. Update Jetpack and Camera Drivers:
   Ensure you’re running the latest version of Jetpack and have the most recent camera drivers installed. Check NVIDIA’s developer website for updates.

2. Adjust Camera Settings:

   • Experiment with different exposure settings to find a balance that reduces oversaturation.
   • Try enabling HDR (High Dynamic Range) mode if available for the IMX477 module.
   • Adjust the camera’s gain and ISO settings to optimize for high-contrast scenes.

3. ISP Tuning:

   • Access the ISP configuration files and adjust parameters related to exposure, contrast, and saturation.
   • Look for settings that control highlight and shadow recovery.

4. Implement Software-based HDR:
   If hardware HDR is not available, consider implementing a software-based HDR solution:

   import cv2
   import numpy as np
   
   def create_hdr_image(images, exposure_times):
       merge_debevec = cv2.createMergeDebevec()
       hdr = merge_debevec.process(images, times=np.array(exposure_times, dtype=np.float32))
       tonemap = cv2.createTonemap(2.2)
       ldr = tonemap.process(hdr)
       return ldr
   

5. Use External Image Processing Libraries:
   Implement additional image processing techniques using libraries like OpenCV to enhance dynamic range in software.

6. Check for Firmware Updates:
   Look for any available firmware updates for the IMX477 camera module that might address dynamic range issues.

7. Experiment with Different Camera Modes:
   If available, try switching between different camera modes (e.g., WDR, HDR, Night mode) to see if any built-in features can mitigate the oversaturation.

8. Implement Local Tone Mapping:
   Apply local tone mapping algorithms to enhance contrast in specific regions of the image without causing global oversaturation.

9. Consider Hardware Modifications:
   As a last resort, you might need to consider using a different camera module with better dynamic range capabilities or adding neutral density filters for extremely bright conditions.

10. Consult NVIDIA Developer Forums:
    Search for similar issues on the NVIDIA Developer Forums and consider posting your specific problem for additional support from the community and NVIDIA experts.

If none of these solutions resolve the issue, it may be necessary to file a bug report with NVIDIA or the camera module manufacturer for further investigation and potential firmware or driver updates.