Manual Exposure when Synchronizing Multiple Azure Kinects

Question

Manual Exposure when Synchronizing Multiple Azure Kinects

Huai Tien 1

Manual exposure when synchronizing multiple Azure Kinects will not produce bright and clear images, but extremely dark ones. How can I solve this problem? I've tried to set manual exposure value from -11 to 1.

LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-09T23:50:44.793+00:00

Hi @Huai Tien , Welcome to Microsoft forum! Thanks for your query. Community SME's on this topic or our team will review your scenario and circle back at the possible earliest time.
Huai Tien 1 Reputation point

2023-01-10T03:19:16.227+00:00

Thanks!
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-10T22:09:42.537+00:00

Hi @Huai Tien , I am checking to see if you have also accounted for Avoiding interference between multiple depth cameras in addition to adjusting the manual exposure.
Huai Tien 1 Reputation point

2023-01-11T09:08:53.1566667+00:00

Hi @LeelaRajeshSayana-MSFT .Yes, I've set depth_delay_off_color_usec to -80 (subordinate) and 80 (master). Thanks for your reply.
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-12T23:15:38.58+00:00

Hi @Huai Tien thank you for the confirmation. We are working on this issue internally. I will update the thread as soon as we have more information on this. Please watch out for updates on this thread in the coming days.
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-17T22:11:36.3566667+00:00
Hi @Huai Tien, Greetings! I have an update from the team on this issue. Here is the feedback I got:

k4arecorder uses -11 to 1 as the range for exposure, but if you look into the code it does a conversion to an actual microsecond value for exposure. Link to GitHub repository

The absoluteExposureValue passed in has to be the exposure time in microseconds, not a value between -11 and 1

Can you provide more details on how you have tried to adjust the manual exposure value. I appreciate it if you can try to set the property in microseconds and see if that produces better image results.

Please keep us posted on your findings.
Huai Tien 1 Reputation point

2023-01-18T06:59:37.46+00:00

OK, @LeelaRajeshSayana-MSFT . For convenience, I use **Azure Kinect recorder **to test it. And the result is the same. I appreciate it if you can have a try and see how it works. Thank you so much.
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-18T21:54:19.4233333+00:00

Hi @Huai Tien Thank you for your response. Azure Kinect recorder uses the k4arecorder to capture videos. Please find the Record files samples provided in the article which uses k4arecorder. Here are the examples provided in the article.

I appreciate it if you can provide some details on how you are setting the manual exposure parameter.

Thank you.
Huai Tien 1 Reputation point

2023-01-19T06:22:59.6+00:00

Hi, @LeelaRajeshSayana-MSFT . I used these commands to get record files.

k4arecorder.exe --device 1 -l 8 --depth-delay -80 -r 30 --imu OFF --external-sync Subordinate -e -7 sub.mkv

k4arecorder.exe --device 0 -l 8 --depth-delay 80 -r 30 --imu OFF --external-sync Master -e -7 master.mkv

Thanks!
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-20T19:31:32.3033333+00:00

Hi @Huai Tien, Thank you for your response. I am working on this internally. Please allow me sometime to get back to you. Kindly watch this thread for updates next week.
Huai Tien 1 Reputation point

2023-01-31T05:11:14.9766667+00:00

Thanks @LeelaRajeshSayana-MSFT . I will have a try this week and check whether it works or not.
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-02-01T23:24:26.7566667+00:00
Hi @Huai Tien, Greetings! We have an update from the team on this issue.

When using 2 cameras, the commands you should be using are as follows:

k4arecorder.exe --device 1 -l 8 -r 30 --imu OFF --external-sync Subordinate --sync-delay 160 -e -7 sub.mkv k4arecorder.exe --device 0 -l 8 -r 30 --imu OFF --external-sync Master -e -7 master.mkv

Team has also recommended to use k4aviewer which provides options to Experiment with camera settings. Please refer the section RGB Camera of the Azure Kinect Viewer for more details on this. Please find the below list of options that are available through K4aviewer which might help with rendering better quality images.

I hope this helps addressing the issue you face.

Huai Tien 1

Hi, @LeelaRajeshSayana-MSFT . When I use your code

k4arecorder.exe --device 1 -l 8 -r 30 --imu OFF --external-sync Subordinate --sync-delay 160 -e -7 sub.mkv
k4arecorder.exe --device 0 -l 8 -r 30 --imu OFF --external-sync Master -e -7 master.mkv

and check, the images can be seen, but they are still a little dark and don't look like normal images even I set exposure time 1 as follows. Thanks for your reply.

k4arecorder.exe --device 1 -l 8 -r 30 --imu OFF --external-sync Subordinate --sync-delay 160 -e 1 sub.mkv
k4arecorder.exe --device 0 -l 8 -r 30 --imu OFF --external-sync Master -e 1 master.mkv

1 answer

Your answer

LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-09T23:50:44.793+00:00

Hi @Huai Tien , Welcome to Microsoft forum! Thanks for your query. Community SME's on this topic or our team will review your scenario and circle back at the possible earliest time.
Huai Tien 1 Reputation point

2023-01-10T03:19:16.227+00:00

Thanks!
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-10T22:09:42.537+00:00

Hi @Huai Tien , I am checking to see if you have also accounted for Avoiding interference between multiple depth cameras in addition to adjusting the manual exposure.
Huai Tien 1 Reputation point

2023-01-11T09:08:53.1566667+00:00

Hi @LeelaRajeshSayana-MSFT .Yes, I've set depth_delay_off_color_usec to -80 (subordinate) and 80 (master). Thanks for your reply.
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-12T23:15:38.58+00:00

Hi @Huai Tien thank you for the confirmation. We are working on this issue internally. I will update the thread as soon as we have more information on this. Please watch out for updates on this thread in the coming days.
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-17T22:11:36.3566667+00:00

Hi @Huai Tien, Greetings! I have an update from the team on this issue. Here is the feedback I got:

k4arecorder uses -11 to 1 as the range for exposure, but if you look into the code it does a conversion to an actual microsecond value for exposure. Link to GitHub repository

The absoluteExposureValue passed in has to be the exposure time in microseconds, not a value between -11 and 1

Can you provide more details on how you have tried to adjust the manual exposure value. I appreciate it if you can try to set the property in microseconds and see if that produces better image results.

Please keep us posted on your findings.
Huai Tien 1 Reputation point

2023-01-18T06:59:37.46+00:00

OK, @LeelaRajeshSayana-MSFT . For convenience, I use **Azure Kinect recorder **to test it. And the result is the same. I appreciate it if you can have a try and see how it works. Thank you so much.
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-18T21:54:19.4233333+00:00

Hi @Huai Tien Thank you for your response. Azure Kinect recorder uses the k4arecorder to capture videos. Please find the Record files samples provided in the article which uses k4arecorder. Here are the examples provided in the article.

I appreciate it if you can provide some details on how you are setting the manual exposure parameter.

Thank you.
Huai Tien 1 Reputation point

2023-01-19T06:22:59.6+00:00

Hi, @LeelaRajeshSayana-MSFT . I used these commands to get record files.

k4arecorder.exe --device 1 -l 8 --depth-delay -80 -r 30 --imu OFF --external-sync Subordinate -e -7 sub.mkv

k4arecorder.exe --device 0 -l 8 --depth-delay 80 -r 30 --imu OFF --external-sync Master -e -7 master.mkv

Thanks!
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-01-20T19:31:32.3033333+00:00

Hi @Huai Tien, Thank you for your response. I am working on this internally. Please allow me sometime to get back to you. Kindly watch this thread for updates next week.
Huai Tien 1 Reputation point

2023-01-31T05:11:14.9766667+00:00

Thanks @LeelaRajeshSayana-MSFT . I will have a try this week and check whether it works or not.
LeelaRajeshSayana-MSFT 17,601 Reputation points

2023-02-01T23:24:26.7566667+00:00

Hi @Huai Tien, Greetings! We have an update from the team on this issue.

When using 2 cameras, the commands you should be using are as follows:

k4arecorder.exe --device 1 -l 8 -r 30 --imu OFF --external-sync Subordinate --sync-delay 160 -e -7 sub.mkv k4arecorder.exe --device 0 -l 8 -r 30 --imu OFF --external-sync Master -e -7 master.mkv

Team has also recommended to use k4aviewer which provides options to Experiment with camera settings. Please refer the section RGB Camera of the Azure Kinect Viewer for more details on this. Please find the below list of options that are available through K4aviewer which might help with rendering better quality images.

I hope this helps addressing the issue you face.
Huai Tien 1 Reputation point

2023-02-13T12:00:56.0033333+00:00

Hi, @LeelaRajeshSayana-MSFT . When I use your code

k4arecorder.exe --device 1 -l 8 -r 30 --imu OFF --external-sync Subordinate --sync-delay 160 -e -7 sub.mkv k4arecorder.exe --device 0 -l 8 -r 30 --imu OFF --external-sync Master -e -7 master.mkv

and check, the images can be seen, but they are still a little dark and don't look like normal images even I set exposure time 1 as follows. Thanks for your reply.

k4arecorder.exe --device 1 -l 8 -r 30 --imu OFF --external-sync Subordinate --sync-delay 160 -e 1 sub.mkv k4arecorder.exe --device 0 -l 8 -r 30 --imu OFF --external-sync Master -e 1 master.mkv

Answer 1

This is an extremely late response, but I will leave it in here just in case someone else stumbles upon the same problem. I had a similar problem as OP, and I found in the documentation that the -e parameter is in microseconds. Thus, when setting manual exposure to work with multiple cameras (and using the out-of-the-box k4arecorder.exe tool), I usually set values in the order of tens of thousands. For a illuminated room with standard office lights, I found that 10000 exposure is good enough. Maybe this was changed in an update after OP's post?

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Manual Exposure when Synchronizing Multiple Azure Kinects

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