Camera images contain motion blur

1. Symptoms

• Features smear in the image when the robot moves or turns.
• Feature tracking or visual odometry loses lock in motion.
• Straight edges look skewed (rolling-shutter effect).

2. Possible causes

• Long exposure in low light (auto-exposure picks a long time).
• Motion: speed, turning rate, vibration.
• Rolling shutter: rows exposed at different times skew moving scenes.
• Focus or lens problem mistaken for blur.
• Gain limited so exposure cannot be shortened.

3. Measurements to collect

• Exposure time and gain for each frame (from the driver or camera API).
• Blur length in pixels ≈ image motion speed (px/s) × exposure time.
• Robot speed and angular rate at the time.
• Light level in the scene.

4. Diagnostic commands

Commands are not executed by the site’s automated tests (they need a ROS 2 Jazzy installation or the robot).

ros2 topic hz /camera/image_raw
ros2 param list /camera_driver | grep -i -E "exposure|gain"
ros2 run rqt_image_view rqt_image_view

5. Step-by-step investigation

1. Read the exposure time and compute blur ≈ pixel speed × exposure.
2. Fix manual exposure to a short value (a few ms) and raise gain or add light; compare tracking.
3. Check the driver’s auto-exposure limits and set a maximum exposure.
4. Slow the motion temporarily to see if blur disappears.
5. Check the shutter type: a global shutter removes skew; with a rolling shutter lower the speed or use readout-time compensation in the estimator.
6. Check focus and lens on a static target.

6. Corrective actions

• Cap exposure and compensate with gain and lighting.
• Use a global-shutter camera for fast motion.
• Mount the camera on a vibration-isolated, stiff bracket.
• Use a faster frame rate with shorter exposure.
• Enable rolling-shutter-aware processing if the estimator supports it.

7. Validation after the fix

• Blur length below about one pixel (or the tracker’s limit) at the maximum speed.
• Feature tracking stays locked through the worst-case turn.
• Timestamps are exposure time (see the camera guide).

References

• sensor_msgs definitions (Jazzy): ros2/common_interfaces, read 2026-11-05. Image: header stamp should be the acquisition time.
• Related guide: cameras guide.